WO2021163459A1 - Mapper and sampler for autonomous analyte detection and recovery - Google Patents

Abstract

A survey and sampling system, and method of using same, including a host, an assessment payload, at least one sampler having at least one sample bottle and sample path. The system enabling in situ detection of at least one analyte and the recovery of fluid samples containing the at least one analyte. The method providing a rapid and inexpensive way to survey an area of interest in a fluid body, establishing local regions of interest where one or more analytes are present, and recovering un-contaminated fluid samples of the one or more analytes.

Description

Mapper and Sampler for Autonomous Analyte Detection and Recovery

CROSS-REFERENCE TO RELATED APPLICATION

[1] This application claims benefit to U.S. Provisional Patent Application No. 62/976,028, filed February 13, 2020, the disclosure of which is hereby incorporated by reference in its entirety.

FTEUD OF THE INVENTION

[2] This invention relates to sampling of a fluid body during a survey in that fluid body. More specifically this invention relates to an autonomous modular sampler utilizing an analyte-free sample path, with a capacity to take multiple fluid samples of the fluid body in conjunction with an autonomous survey.

BACKGROUND OF THE INVENTION

[3] Hydrocarbons enter ocean water from a variety of sources including natural seeps, spills from wells, pipelines, and surface activities. Underwater releases of hydrocarbons can be difficult to track. Responders to a hydrocarbon spill confront a rapidly-evolving three-dimensional (3D) mixture of fluids which changes with tidal and weather cycles; an area with high concentrations of hydrocarbons one day may be undetectable the next day. Water sampling is used to confirm qualitative observations of an oil slick and to measure concentrations of various classes of hydrocarbons.

[4] When released underwater, a hydrocarbon plume is transported by ocean currents and its own buoyancy. The plume may reach the surface, forming a surface expression, or “slick,” which can be detected from a ship, airplane or satellite, often using visible light or infrared cameras. Synthetic aperture radar (SAR) may also be used to detect the distinctive signatures of an oil slick (for example, differential solar heating, attenuated wave heights, and decreased microwave scattering). However, remote detection of oil is qualitative. Optical and radar images are susceptible to Took alikes’ patterns of water temperature or surface roughness that appear to be oil spills but are not. A remotely sensed oil slick may be verified only by surface water sampling and analysis.

[5] Underwater plumes are more challenging to detect, typically requiring towed or remotely operated underwater vehicles (ROVs). Some underwater plumes may be neutrally buoyant at depth with no obvious connection to a surface feature. In situ sensors produce immediate measurements, which have been essential during disaster response. One such sensor is the Seabird SeaOWL UV- A oil-in-water sensor, which detects dissolved organic material (FDOM) via fluorescence (excitation at 370 nm, emission at 460 nm). The Sea Owl also measures chlorophyll fluorescence (excitation at 470nm, emission at 690nm) and backscatter at 700nm, which can help to disambiguate hydrocarbons from other sources of FDOM. However, this sensor alone cannot differentiate classes of hydrocarbons and cannot measure concentrations. Other in situ sensors used to detect oil include sonar and holographic cameras, also are subject to ambiguities.

[6] While in situ sensors can detect the presence of hydrocarbons, only laboratory analysis of water samples allows for the measurement of type and concentration of hydrocarbons present in a plume. During the response to an oil spill, towed and tethered ROVs offer intuitive, immediate feedback to remote human operators, and the possibility for intervention which is an indispensable capability during disaster response. However, crewed surface vehicles and ROVs are costly and slow to deploy.

[7] Autonomous vehicles offer a complementary and ideal platform for monitoring underwater hydrocarbon plumes using optical in situ sensors at low cost. AUVs offer remote access while minimizing human exposure to hazardous environmental conditions. Capable AUVs can often be mobilized quickly, reaching a spill site in a day or two, while ROVs and submersibles may take longer to prepare. AUVs can work nonstop, night and day, and cover a large area, to find underwater hydrocarbons that may not be connected to any known surface expression. Autonomous vehicles extend the utility of limited ship time by allowing the ship to perform other tasks such as emergency response or mitigation, while an autonomous vehicle uploads its latest survey results periodically via a wireless connection (e.g., acoustics, radio connections, or satellite communications).

[8] AUVs can be programmed to dive in a pattern (e.g. lawnmower or sawtooth pattern), creating an XY grid map or YZ section view, both of which are impractical with a submersible or ROV. This type of mid-water survey is possible with a towed platform, though it monopolizes use of limited ship time. With each surfacing, an AUV can relay data via satellite to a land-based server for human consumption. AUVs can be programmed to perform a progressive search, first covering the search space with widely-spaced profiles, later re-tasking to areas of interest with a fine-scale survey. Zones of water with above-average fluorescence can be revisited automatically or programmatically. This multi-scale survey can be automated and is adaptable depending on mission objectives.

[9] Disaster response depends on the complementary observations of satellite and aerial remote sensing, shipboard measurements, remotely operated and autonomous vehicles, all of which have an important role in understanding flows of oil introduced into a fluid body (e.g., the ocean).

[10] However only analysis of water samples can measure concentration of hydrocarbon classes. A typical analysis using gas chromatography - mass spectroscopy (GC - MS) can identify and discriminate 91 well-known hydrocarbons, producing a fingerprint of the hydrocarbon source. Accurate concentration measurements are important in oil spill assessment, and are also used to interpret and calibrate in situ fluorometry.

[11] Challenges of oil-in-water sample collection. Water sampling in an oil spill is challenging due in part to limited platform availability and site access restrictions. Careful handling and decontamination procedures must also be followed to ensure accurate sample analysis. Water sampling has previously been done from a crewed surface ship. For depths to 10 meters (m), bottles or inlet tubing may be manually lowered over the side. Deeper samples may be collected in Niskin, Goflo or gas-tight bottles, mounted on a CTD rosette on an ROV. Directed water sampling is ideal for point sources such as a leaking tank or wellhead. However, hydrocarbon sources may be multiple, diffuse, or unknown. In these cases, a larger area may need to be sampled, which may not be feasible from a ship or ROV.

[12] Difficulties of collecting water without the sample container affecting it have been documented. Many samplers, including most Niskin bottles, are made of hydrocarbon-based plastics. If samples are temporarily stored in plastic bottles, hydrocarbons can leach from the bottle to the water sample, contaminating the sample.

[13] On the other hand, if water is collected in one bottle and then transferred to another, sampled oil may remain in the first bottle, stuck to the sides (i.e., an oil film), lowering the measured concentration or increasing a second sample collected in the same, first bottle. Volatile hydrocarbons may diffuse through a plastic bottle and escape before analysis. To minimize these effects, glass or metal bottles should be used for hydrocarbon sampling.

[14] Decontamination of sampling equipment can be a challenge, since clean water may be in short supply. Often site water is used for decontamination of equipment, even though this water may be contaminated with hydrocarbons. Similarly, a highly concentrated surface slick may coat collection equipment that is lowered from a ship to deeper water, causing oil to be detected at depths where there is none. If a common inlet tube is used to collect multiple samples at several locations, a high concentration of oil at one site may contaminate the inlet and then bleed into later samples. For analysis, water samples should be kept cold and returned to a lab within a few days for most accurate analysis of hydrocarbons.

[15] Previous attempts at water sampling. Several previous autonomous samplers inform the design of the present invention. Klump et al. 1992 used a peristaltic pump to collect water from hydrothermal vents, stored in one of 16 loops of rubber tubing, each 25 ml, selected by a multiport valve. Envirotech Instruments and Lamont Doherty developed the Aqualab sampler which uses plastic tubing and 49 ethylene-vinyl acetate (EVA) pouches for sample storage and takes 10 to 25 minutes to collect each 200 ml sample. Aqualab, integrated with the Autosub AUV, successfully collected water beneath fjords in East Greenland in 2004 for isotope ratio analysis, demonstrating the utility of using autonomous vehicles to retrieve samples from otherwise inaccessible sites. Slow collection speed, small sample size, unreliable multiport valve, and hydrocarbons in the sample path make this system not well suited to hydrocarbon sampling.

[16] Suspended Particulate Rosette (SUPR) samplers are a family of samplers that have been deployed on moorings, ROV, and AUVs. SUPR samplers are based on a system comprised of a multiport valve and single pump. At specified locations or intervals, the multiport valve selects a particular channel and pumps water through filters and/or fills bottles, which are reconfigurable for particular applications. The SUPR’s individual per-sample inlet and downstream pump help reduce cross-contamination.

[17] The MBARI Gulper was developed at Monterey Bay Aquarium Research Institute to replace manual shipboard water collection for primary-productivity time-series measurements. The Gulper uses polymethyl methacrylate (PMMA or “acrylic”) plastic sample cylinders, silicone o-rings and silicone lubricants, these materials selected for consistent phytoplankton growth. For high spatial resolution, the spring-driven syringe can collect each 2-liter sample in less than 2 seconds. The MBARI Gulper was also deployed to collect hydrocarbon samples during Deepwater Horizon although water sampling did not occur due to a flooded controller housing. The fast sampling speed and unique peak-capture triggering algorithm are excellent assets for hydrocarbon sampling. However, the hydrocarbon-based materials and lubricants would likely influence hydrocarbon measurements and decontamination of the reusable bottles would be difficult.

[18] With the exception of the 2-liter MBARI Gulper sampler, most existing samplers collect much less than 1 L per sample. For low hydrocarbon concentrations, and lower measurement limits, larger volumes of water are necessary. From recent experience tracking the plume from the 2010 Deepwater Horizon spill, 500 ml is the minimum volume necessary for measuring hydrocarbon plume and 1 L is a good compromise which facilitates handling and processing samples, while still allowing low detection thresholds.

[19] Furthermore, most existing samplers use hydrocarbon-based plastics in contact with the sample. Plastic and foil packages introduce measurable amounts of hydrocarbons into captured water, making any fluid sampled for hydrocarbons useless from contamination.

[20] Therefore, there is a need for a device and method with improved surveying, sampling, simplified sample decontamination, and minimized sample cross-contamination, typically using single-use disposable sampling equipment. There is also a need to minimize handling time, using a system where samples are quickly secured for shipment to a laboratory for analysis.

SUMMARY

[21] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. One object of the present invention is a device for analyzing and sampling a fluid body, the device having an assessment payload having a first inlet tubing, a first upstream valve connected to the first inlet tubing, a first bottle adaptor connected to the first upstream valve, and a first propagator connected to the first bottle adaptor. The assessment payload further has a first sample bottle configured to reversibly attach to the first bottle adaptor and store a fluid sample. The first propagator is configured to move fluid from the fluid body through the first inlet tubing, the first upstream valve and the first bottle adaptor and into the first sample bottle.

The device further includes a first sensor that produces sensor information, and a controller electronically connected to the first sensor and first propagator, where the controller is configured to receive the sensor information from the first sensor and activate the first propagator. In some cases, the controller activates the first propagator in response to the sensor information where the sensor information relates to a first analyte in the fluid body. In some cases, the assessment payload further has a second inlet tubing, a second upstream valve connected to the second inlet tubing, a second bottle adaptor connected to the second upstream valve, a second propagator connected to the second bottle adaptor, and a second sample bottle configured to reversibly fasten to the second bottle adaptor and store a second fluid sample; the second propagator is configured to activate the second propagator. In some cases, the controller activates the second propagator in response to the sensor information where the sensor information relates to the first analyte in the fluid body. In some of these cases, the first and second inlet tubing, the first and second upstream valves, the first and second bottle adaptors, the first and second propagators, and the first and second sample bottles are within a sampler. In further cases, the sampler is reversibly fastened in the assessment platform. In some further cases, the controller is located within the sampler. In other cases, the controller is located within the assessment payload.

[22] In another aspect of the invention is the device described first above where the controller is further configured to establish a region of interest (ROI) and to activate the first propagator when the device is located within the first ROI, where this first ROI relates to the sensor information. In some of these cases the device further comprises a host connected to the assessment payload and electronically connected to the controller, where the host is configured to move through the fluid body and the controller is configured to instruct the host to move though the fluid body. In some cases, the controller is configured to instruct the host to move to the first region of interest. In some cases, the first inlet tubing, the first upstream valve, the first bottle adaptor, and the first sample bottle have negligible amounts of semi-volatile materials; in further cases, these components adhere to the U.S. Environmental Protection Agency (EPA) standards for semi-volatile materials for hydrocarbon fluid sampling. In some embodiments, the assessment payload further has a cover with a first slot, where the cover is configured to reversibly fasten to the assessment payload and the first inlet tubing extends though the first slot.

[23] Another object of this invention is a method of analyzing and sampling in a fluid body, the method having the steps of (a) providing a device with an assessment payload, a first sensor, a controller, and a first sampler having a first sample bottle and a first sample path. The sample path having a first inlet tubing, a first upstream valve, a first bottle adaptor, and a first propagator. The method including steps (b) moving the device through a survey area in a fluid body and producing sensor information from the sensor, the sensor information relating to an analyte, (c) designating a first region of interest relating to the sensor information in the survey area, and (d) activating the first propagator to take a first fluid sample using the first sample path. In some methods, step (d) occurs at the first region of interest. Some methods include the step of moving away from the first region or interest and returning to the first region of interest to perform step (d). In some uses, the method includes the step of (e) designating a second region of interest relating to the sensor information in the sensor area. And still further, the steps of (f) comparing with the controller, the sensor information in the first region of interest with the sensor information in the second region of interest and (g) choosing a region of interest to activate the first propagator in step (d). In some uses, step (g) chooses between the first and second region of interests.

[24] In some uses, the above first method further includes where the first sampler has a second fluid path having a second inlet tubing, a second upstream valve, a second bottle adaptor, and a second propagator. In some of these uses, the method further comprises the step of (h) activating the second propagator to take a second fluid sample using the second sample path. In still further of these uses, the method further comprises the step of (i) designating a second region of interest relating to the sensor information in the survey area and where step (h) occurs at the second region of interest and after step (i). In some uses, building on the first method described above, the first sample path connects to no other sample bottles, that is to say that the first sample path is independent of any other sample paths and their associated sample bottles; the first sample path connects only to the first sample bottle.

[25] In some uses, the above first method further includes the steps of (k) removing the device from the fluid body, (1) removing the first sample bottle from the device, (m) attaching a clean sample bottle onto the first bottle adaptor, and (n) placing the device into the fluid body. In some of these uses the method further includes the step of (o) removing the first sampler from the device before step (1); (p) replacing the sampler into the device after step (m). In some uses, the method further includes the step of (q) repeating steps (b) through (d).

BRIEF DESCRIPTION OF THE DRAWINGS [26] In what follows, preferred embodiments of the invention are explained in more detail with reference to the drawings, in which:

[27] FIG. 1A is a block diagram overview of the inventive system 100 and surveying method 200

[28] FIG. IB is an exploded schematic view depicting the disclosed assessment payload 103 and sampler 104 according to one embodiment.

[29] FIG. 1C is a schematic view of a fluid path 108 according to one embodiment.

[30] FIG. 2 is an angled side view of one embodiment showing the host 102 having a nose cone 128, sensors 114, and an assessment payload 103 comprising two covered samplers 104.

[31] FIGS. 3 A and 3B are a two views of one representative pattern of one possible survey pattern 204 for an autonomous system 100 to conduct while searching for analyte hotspots (e.g., regions of interest), according to one embodiment. FIG. 3 A is depicts low level (<6 to < 9><10⁴ concentration) analyte readings in dark lines, while FIG. 3B is the same survey pattern 204 where high levels (>9 to ~ 1 1 ^c 10⁴ concentration) analyte readings are in dark lines (i.e., inverted from FIG. 3A).

[32] FIGS. 4A-4H illustrate one embodiment and its associated sensor information 136. FIG. 4 A is an image of an analyte (oil droplets) in the fluid body as the device 101 performs a survey, FIG. 5B shows the path of a device along with a grey-scale coloring relating to the sensor information of analyte concentration and FIGS. 4C-4H depict different sensor information and analyte parameters as determined by the controller during the survey.

[33] FIG. 5A is a graphical representation of hydrocarbons (i.e. analytes) in recovered fluid samples during a survey and FIG. 5B is a graphical representation of salinity in the same samples as shown in FIG. 5 A.

[34] FIG. 6 schematically illustrates one survey method for detecting at least one analyte in a fluid body, and a sampling method thereof.

DEFINITIONS

[35] The terms “front” and “forward” as used herein refer to the bow of the host, typically the front is in the direction in which the host 102 and overall system 100 moves through the fluid body.

[36] The term “inlet tubing” as used herein refers to any suitable mechanism to enable fluid intake from the liquid environment into the fluid path. In the currently preferred embodiment, the inlet tubing is a tube, but it may take different, non-tube physical forms. PET ATT, ED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Overview

[37] This invention may be accomplished, as illustrated conceptually in FIG. 1 A, by providing a system 100 having a device 101 comprising a host support platform 102 and an assessment payload 103 for assessing and sampling an analyte in a fluid body. The host 102 moves about a fluid body 105 (e.g., the ocean). The assessment payload 103 comprising one or more samplers 104a, 104b, each sampler 104 having components necessary for taking a fluid sample 106 from that fluid body 105 for analysis of at least one analyte, all without contaminating the sample 106 with any of the analytes to be analysed by the components of the sampler 104 or from other samples. This invention further provides a surveying method 200 to move through a fluid body 105, preferably autonomously, and picking sampling locations 203a, 203b in real-time based on in situ analyte detection. The present invention allows for fast, efficient, and inexpensive sampling of analytes in a fluid body. Furthermore, device 101 may be turned over quickly, with fast removal of filled sample bottles (depicted as arrows 132), replacement with clean, empty sample bottles (arrows 133), are redeployment of device 101 in the fluid body (arrow 134).

[38] As illustrated in FIGS. IB and 2, the currently preferred embodiment is a device 101 with a host 102 and an assessment payload 103 that accepts one or more samplers 104. The sampler 104 comprises one or more sample bottles 107, a sample path 108 to move fluid from the fluid body 105 to a sample bottle 107 using a fluid moving mechanism (e.g., a pump), referred herein as the propagator 109.

[39] As illustrated in FIG. 1A and the resulting surveyed analyte in FIGS. 3A and 3B, the present invention provides the above components with the ability to conduct a survey method 200 in the fluid body 105, covering a survey area 201 to detect an analyte of interest, establish one or more regions of interest (ROI) 202, assigning sampling locations 203a-b at one or more ROIs, and to recover fluid samples 106 from the sampling locations 203a-b for later analysis. Preferably, the survey, establishment of ROIs, and sampling is done entirely autonomously. Each component and feature of the present invention will be further described in detail herein below.

Host [40] The present invention provides for a host support platform 102, referred herein as the host, which in some embodiments enables the overall system 100 to execute the necessary tasks. The host 102 may be any suitable object or vehicle that enables the invention. Typically, the host 102 supports the assessment payload 103, allowing the samplers 104 to take in fluids while submerged and constrain and protect the samplers while moving through the fluid body 105. In most embodiments, the host 102 is mobile and enables the system 100 to move through the fluid body (i.e. the liquid environment). The host 102 is interconnected with a digital control device (referred herein as the controller) 116, which is configured to instruct the host 102 on where and when to move. For example, the controller 116 may designate a region of interest 202, and instruct the host to return to that region of interest after a survey for sampling 207. In the currently preferred embodiment, the host 102 comprises an autonomous, self-propelled AUV with at least 36 cm diameter with an assessment payload 103 designed to accept one or more samplers 104. The size of the host 102 is most often dictated by the size and number of the samplers and the size (i.e., volume) of the sample bottles 107. In the currently preferred embodiment, the assessment payload 103 comprises two samplers 104a, 104b, each sampler 104 having two rows of three, one-liter sample bottles 107 (for a total of 6 sample bottles 107 per sampler 104), dictating a host 102 of approximately 36 cm. In another embodiment, the assessment payload 103 comprises a single sampler 104 having three sample bottles 107 in a single row and prefers a host of 18 cm in diameter.

[41] The host 102 provides connections 110 for data and power transfer to the assessment payload 103 and sampler(s). For example, a typical host 102 connection 110 provides multiple RS-232 serial connections, multiple gigabit ethernet ports, and multiple switchable 12 volts DC (VDC) and 28 VDC power supplies. The host 102 may comprise a towed body, a remotely operated vehicle (ROV), a human-occupied submarine or surface vehicle, an autonomous underwater glider (AUG), an autonomous surface vehicle (ASV), a drifting buoy, or the like. Assessment payload

[42] The samplers described herein are preferably incorporated into an assessment payload 103 for easy integration into the host 102, including fast attachment to the host 102 and its connections 110. The assessment payload 103 further enables quick removal of the sample bottles 107 and quick assembly of the samplers 104 into the device 101. The assessment payload 103 is attached to the host 102 via a joint mechanism, or joiner 111. The joiner 111 results a quick and secure attachment of the assessment payload 103 to the host 102, allowing for the device 101 to perform its survey mission 200, while ensuring that the assessment payload may be easily removed from the host 102. Furthermore, the one or more samplers 104 can be quickly and easily removed from the assessment payload. Samplers 104 may be removed from the assessment payload via reversible fasteners 130 (after cover 112 removal by reversible fasteners 129). The sample bottles 107 are removable from the system 100 by their reversible attachment to the bottle adaptors 120. Typically, sample bottles 107 are removed only after a sampler 104 is removed from assessment payload 103.

[43] In the currently preferred embodiment, the joiner 111 comprises 32 cm diameter ring joints. Typically, the assessment payload 103 includes a cover 112, often with buoyancy compensation (e.g., syntactic foam) built in that covers and protects the loaded samplers 104. Typically, the cover does not seal the samplers 104 from the fluid body 105 environment. Preferably, the cover is designed to easily allow the inlet tubes 117 to project out through the cover 112 into the fluid body 105, as shown in FIG. IB with inlet tube passthrough slots 135. Removal of the cover 112 enables access to the samplers 104 while they are loaded into the assessment payload 103.

[44] The assessment payload 103 preferably also comprises electrical connections 113, typically for both information and power connections from the host 102 to the sampler 104 or samplers. The connections 113 may be any suitable connection as known in the art. In the currently preferred embodiment, the connections include at least one RS-232 serial connection, at least one ethernet port, and at least one switchable 12 VDC and 28 VDC power connection. Additional sensors 114, discussed below, may also be attached to the assessment payload 103.

Sampler

[45] The present invention provides a novel sampling mechanism for collecting fluid samples from a larger fluid body. The sampling mechanism, referred herein as simply the sampler 104, is a module that may be incorporated into the overall device 101, and further comprises sample paths 108, sample bottles 106, and electrical connections 113.

[46] In some embodiments, the sampler 104 further comprises a central junction-box sub-assembly 115 that holds the propagator 109, a controller 116, and all electrical wiring sealed to be water-tight. While the one or more samplers 104 may comprise a single sample bottle 107 and sample path 108, most embodiments will typically have samplers with multiple sample bottles, and multiple sample paths 108. In order to eliminate sample cross-contamination, each sample bottle and connected sample path 108 is independent of each other in a sampler 104. That is, one sample path 108 connects to one sample bottle 107. One embodiment is illustrated in FIG. IB, where sampler 104 comprises six sample paths 108a-f and each connect to a single sample bottle 107a-f. The one or more sample paths 108, as conceptually illustrated in FIG. 1C, comprise an inlet tube 117, an upstream check valve 118 (upstream of the sample bottle 107), a bottle adaptor 120, a downstream check valve 121, a propagator (e.g., a pump) 109, and an outlet tube 122. The components within the sampler 104 will be described in more detail below herein.

Sample bottles

[47] Physical containers are provided to capture and store fluid samples 106 from the fluid body 105 during device 101 use and are referred herein as sample bottles 107. Sample bottles 107 may comprise any suitable shape, size, or material according to the embodiment. In the currently preferred embodiment, the sample bottles 107 comprise one-liter cylindrical glass bottles; preferably single-use, wide mouth, hydrocarbon free, darkened glass bottles. The sample bottles 107 are preferably commercially available and interchangeable to speed sampling and redeployment. In the currently preferred embodiment, the sample bottles 107 are certified by the vendor to meet EPA standard 1992 (United States Environmental Protection Agency Office of Emergency and Remedial Response, Specifications and guidance for contaminant-free sample containers. Directive 9240.0-05A, EPA Publication 540/R-93/051, December 1992, incorporated by reference herein) having negligible amounts of semi-volatile materials, organics, or any other contaminants. In some embodiments, the sample bottles 107 have less than the maximum permissible concentration of organic materials allowed for sample containers, based on the organic Contract Laboratory Program sample sizes and sample container material multiplied by contract required detection limits, as defined by EPA standard 1992.

[48] For underwater embodiments, the sample bottles 107 are preferably pre-filled with a clean fluid, lacking the analyte of interest (e.g., pre-filled with distilled water). Pre-filling the sample bottles 107 enables the device 101 to be closer to the desired buoyancy, typically neutral to slightly positively buoyant. Pre-filling may be done by attaching the inlet tube 117 or the inlet barb 119 of the upstream check valve 118 to a desired clean fluid source and activating the appropriate propagator 109. Typically, pre-filling is performed while the sampler 104 is not loaded into an assessment payload 103. Once the bottles 107 are pre-filled, the samplers 104 are placed into an assessment payload 103 (if present in the embodiment) and loaded into or onto the host 102. [49] For removal of the sample bottles 107 from the device 101, a sampler 104 is preferably secured to a service cradle 123, and the bottles are typically only attached to a sampler 104 by a bottle adaptor 120. In one embodiment, the sample bottles 107 comprise threaded necks that are screwed into accepting threads of the bottle adaptors 120. It is within the scope of the present invention for other solutions for the sample bottle 107 to attach to the bottle adaptors 120, as known in the art, for example swing top gasket clip-on attachments. Sample bottles 107 unattached to the bottle adaptors 120 may be closed (e.g., capped) by an appropriate solution; for example, a screw cap. Preferably, filled and capped sample bottles 107 are labeled, barcoded, or otherwise identified, placed into the appropriate environmental control (e.g., a cooler or other temperature control solution) and transported to an analytical laboratory. The entire sample bottle 107 is transported and no bottle to bottle transfer is required with the present invention. In some embodiments the sample bottle size and material for the appropriate analyte adhere to the EPA Region 9 Sample Container and Preservation List, incorporated by reference herein.

Analyte

[50] The present invention is designed to sample a fluid body 105 for one or more analytes of interest. The system 100 and device 101 provides sensors 114 for the in situ detection of analytes in the fluid body 105, as well as for sample bottles 107 to recover fluid samples 106 for later analysis of the one or more analytes. The analyte may be any substance of interest. In the currently preferred embodiment, the analytes are hydrocarbon compounds; more particularly, hydrocarbon compounds found in natural oil seeps or hydrocarbon compounds found in oil spills. The analyte of interest may dictate different aspects of the included components of a given embodiment. For example, a specific analyte may dictate the size of the sample bottles 107. A specific analyte may also dictate the material used for the sample bottles 107 and the sample paths 108. For example, in the currently preferred embodiment, no plastic (i.e., hydrocarbon-based) or volatile materials are used in the materials that make up the sample path 108 or sample bottle 107 due to the contamination of the sample 106 with leaching hydrocarbons from these components.

Sample path

[51] To collect a sample 106, fluid enters a sample path 108 from the fluid environment. Fluid is moved by the propagator 109, and backflow is restricted by the upstream and downstream valves 118 and 121. In the currently preferred embodiment, the sample path 108 begins with inlet tubing 117, comprising a 15 cm long PTFE tube. The inlet tube 117 may be of any suitable material, depending on the embodiment. Preferably it does not contain any volatile materials, is resistant to impacts, maintains its desired shape during device 101 movement (e.g., the inlet tube 117 remains perpendicular to the assessment payload 103) and is replaceable. Here volatile materials include materials that have chemicals that are readily vaporized; partial vaporized at normal temperatures and pressures and vaporized when placed in environments with elevated temperatures and pressures. Downstream of the inlet tube 117, fluid enters the inlet barb 119 of the upstream valve 118, typically a one-way valve, to prevent fluid backflow (where backflow is defined as fluid movement in the reverse direction than the direction when the fluid is moved by the propagator 109), through a bottle adaptor 120, and into a sample bottle 107. The one-way property of the valves maintains the fluid sample 106 inside the sample bottle 107 and prevents contamination of other fluids or fluid from the fluid body 105 entering from different physical locations, as system 100 operates. Typically, valves 118, 121 contain a means to prevent backflow; in the currently preferred embodiment, the upstream and downstream valves 118, 121 are check valves that are sealed closed by springs when fluid is not moving in the appropriate direction (e.g., moved by a pump 109). Bottle adaptors 120 comprise a release mechanism 124 for the sample bottle 107, and inlet 125 for the upstream sample path 108a and an outlet 126 for the downstream sample path 108b. Bottle adaptors 120 may be any suitable mechanism as known in the art. Bottle adaptors 120 enable a water-tight connection between upstream valve 118 and sample bottle 107 and enable the removal of the sample bottle 107 from the sampler 104 via the release mechanism 124. In some embodiments, the bottle adaptor 120 further comprises a fill tube 127 that enables the sample bottle 107 to be filled with sample fluid 106 from the bottom of the bottle to the top, ensuring any substance inside the sample bottle 107 (i.e., pre-fill) to be expelled by the inflowing sample 106. [52] The downstream sample path 108b of the sample bottle 107 may comprise a downstream valve 121 connected to the adaptor outlet 126, which in turn is connected to a propagator 109. The downstream valve 121 is most often a one-way valve. The propagator 109 is connected to an outlet tube 122, which enables fluid to leave the sample path 108 and device 101. In some embodiments, the propagator 109 is connected directly to the bottle adaptor 120. The propagator 109 provides the motive force to move fluid from the fluid body 105 into and through the sample path 108. The propagator further fills the sample bottle 107 with the fluid sample 106, and in most embodiments, provides the force to remove any pre-fill inside a sample bottle. The propagator 109 may be any suitable mechanism as known in the art; preferably, it is submersible, sealed against water ingress and potted without voids such that it is pressure tolerant. In the currently preferred embodiment, each sample path 108 connects to a single sample bottle 107 and has a dedicated propagator 109. In other, less preferred embodiments, multiple sample paths 108 connect to a single, multi-channel propagator 109.

[53] In the currently preferred embodiment, multiple sample paths are completely independent. That is, one sample path does not connect to any components of another sample path. This independency allows for multiple sample collection, without a previous collected sample contaminating subsequent samples as they pass through a used sample path. It is envisioned that no sample path will be reused during a mission, and if the device 101 is redeployed, that sample bottles 107 and sample paths 108 will be replaced or at least cleaned. The sample path 108 may be modified during use. For example, filling the sample bottles 107 with a pre-fill fluid may be done with one inlet tube 117, and then a fresh inlet tube 117 may be added to the sample path 108 to ensure no contaminations are introduced. Likewise, before redeploying a system 100, sections of the sample path 108 may be exchanged for fresh, uncontaminated components. In the currently preferred embodiment, the sample path 108 comprises materials to minimize hydrocarbon contamination, including stainless steel and fluoropolymers.

Sensors

[54] To facilitate sampling, the device 101 may comprise additional analyte detecting sensors 114. The sensors 114 may be any suitable sensor known in the art and will differ according to the embodiment. The location of the sensors 114 may also change depending on the embodiment. In some embodiments, one or more sensors 114 may be attached to or incorporated into the host 102. The one or more sensors 114 may be attached to or incorporated into the assessment payload 103 or a nose cone 128 attached to an assessment payload 103 (typically, on a side of the assessment payload opposite from the host 102). Properties of the environment sensed by sensors 114 produces sensor information 136. Sensors 114 are electronically connected to the controller 116 such that sensor information 136 (i.e., data) generated by a sensor 114 is transferred to the controller 116 is a machine-readable format.

[55] In the currently preferred embodiment, the sensors 114 include an in situ optical sensor, for example a PAR sensor that measures downwelling sunlight. A second optical sensor is incorporated into the currently preferred embodiment to detect colored dissolved organic matter (CDOM), fluorescent dissolved organic matter (FDOM) and chlorophyll. CDOM is the optically measurable component of dissolved organic matter and FDOM is the fraction of CDOM that fluoresces. These three optical channels are ideal for embodiments that are adapted for sampling dissolved hydrocarbons. Additional sensors 114 may include oxygen concentration sensors, cameras, temperature probes, conductivity, temperature and density (CTD) sensors, and the like.

[56] The currently preferred embodiment comprises at least two visual camera sensors to detect hydrocarbons. A forward-facing 3D holographic camera captures an undisturbed section of fluid as the device 101 approaches that section of fluid, allowing the device 101 to measure oil droplet size and droplet size distributions. The currently preferred embodiment also comprises a forward facing video camera to capture continuous video. These camera systems are incorporated into a custom nose cone 128 that is attached to the assessment payload 103. The host 102 is then attached at the opposite (reward) side of the assessment payload 103.

Controller

[57] A digital controller 116 is provided to control and collect data from the various components of the system 100. Typically, the controller 116 is electronically connected to the propagators 109 and sensors 114 incorporated into the device 101. The controller 116 is often electronically connected to host 102. The connection between controller 116 and propagator 109 may be direct, or indirect via the propagators power connection. For example, the controller may activate a propagator 109 by switching that propagator’s power connection on and thereby turning on the propagator 109. The controller 116 is further capable of determining one or more parameters or properties of the analyte from the sensor information 136 obtained through its connection to the sensor 114. Often, the parameter determined by the controller 116 is a concentration of the analyte. The controller 116 may then record or otherwise log the analyte parameter, often along with location at which the parameter was determined. For example, FIGS. 3 A and 3B graphically illustrate analyte concentration (a parameter) over time (x-axis) and space (y-axis), here in FIGS. 3A and 3B space is depth, where device 101 performed a yo-yo survey pattern 204 around a central point (an oil drilling platform) during a survey pattern 204. FIGS.

3 A and 3B do no illustrate the 3D nature of the survey pattern 204, where the device 101 moves in latitude and longitude. Other parameters include, but are not limited to, temperature, analyte physical appearance or size (e.g., oil droplet size), and density of analyte. Controller 116 may further establish regions of interest 202 and sampling locations 203 for immediate or later sampling 207, these locations typically relate to parameters or sensor information that is higher than at other locations. Regions of interest and sampling locations may be logged in storage by the controller. As the system 100 performs a survey method 200, the controller 116 may log additional regions of interest or sampling locations. Once a survey is complete, the controller 116 may compare the sensor information relating to each logged ROIs or sampling locations to choose to which ROIs or sampling locations device 101 will return to for sampling 207. A subset of ROIs or sampling locations are chosen autonomously by the controller 116, often based on which ROIs or sampling locations have the highest concentration of analyte (as determined by the sensor information and controller). A subset of previously logged ROIs 202 or sampling locations 203 will then not be returned to for sampling 207 by device 101.

[58] The controller 116 may be physically located in any suitable part of the device 101. Typically, the controller 116 is a printed circuit board with a supervisory microcontroller, and device 101 comprises one controller 116 for each sampler 104. In one embodiment, the controller 116 is incorporated into the host 102. In other embodiments, the controller 116 is within the assessment payload 103. The controller 116 may comprise a separate, dedicated controller for the connected components or as the host’s main controller (e.g., an AUV’s digital controller). Analytical laboratory

[59] The present invention provides a system 100 and method 200 to detect one or more analytes in a fluid body 105 and to recover fluid samples 106 containing the one or more analytes. Typically, in situ analysis of the analyte is not possible or does not result in measurements with sufficient precision or accuracy. Therefore, for most embodiments of the invention, the sample bottles 107 are removed from the device 101 for shipping to an analytical laboratory that may provide measurements of sufficient precision and accuracy. The exact capabilities of the analytical laboratory may depend on the embodiment and are known in the art. In some embodiments, the measurements and testing adhere to the EPA publication, Test Methods for Evaluating Solid Waste: Physical/Chemical Methods, also known as SW-846, incorporated by reference herein. Some analytes in embodiments disclosed herein are measured according to Method 524.3, entitled “Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography /Mass Spectrometry” from the EPA, published as EPA Publication 615-B-09- 009 and incorporated by reference herein.

Service cradle [60] Preferably the sample bottles 107 and samplers 104 are easily removable from the device 101. Typically, the assessment payload 103 has a cover 112, which may be removed after reversible fasteners 129 (e.g., screws) are removed. The sampler 104 is also secured with reversible fasteners 130, removal of which allows the sampler 104 to be separated from the assessment payload 103 and the overall device 101. Electrical connections are preferably removable, with known in the art reversible connectors. The unsecured sampler 104 is removable from device 101 and may be placed in a service cradle 123 for service, sample bottle 107 access, cleaning, redeployment preparation, and the like. The service cradle 123 may be any suitable physical apparatus, preferably enabling access and a secure attachment of one or more samplers 104 while the one or more samplers 104 are not connected to the assessment payload 103.

Survey and sampling pattern and algorithm

[61 ] The present invention provides a method 200 of autonomously surveying a survey area 201 in a fluid body 105 for at least one analyte, to assign local regions of interest (ROIs) 202 inside the survey area 201, and to autonomously recover fluid samples 106 from the one or more ROIs 202. The survey method 200 in its entirety is also referred herein as a “mission”. A survey area 201 is typically defined by a user before device 101 deployment and programmed into the controller 116, often using an absolute coordinating system (e.g., GPS coordinates). A survey pattern 204 may also be selected before deployment. In some embodiments the system 100 autonomously determines the survey pattern 204 to be performed. The device 101 is deployed and begins executing the survey pattern 204, while operating any sensors 114 to detect the analyte (e.g., hydrocarbons) in the fluid body 105. Upon analyte detection, the device 101 may designate a ROI

202 and may either immediately override the survey pattern 204 to establish a sampling location

203 and recover a fluid sample 106, compare the analyte concentration to a threshold for recovery, log the ROI 202, or log a sampling location 203 for recovery of a sample 106 in the future. An analyte concentration threshold may be pre-set by a user, communicated to the system 100 in real time or dynamically assigned based on analyte concentrations detected during the current mission or during previous missions. Sampling locations 203 have coordinates and a depth. Coordinates may be in the absolute reference frame (latitude and longitude), or in a relative reference frame. Typically, a sampling location 203 is a precise point at a precise depth and the surrounding area (typically a 10 meter volume around a point), while a region of interest 202 represents a larger area not at a single depth. A ROI 202 may be further surveyed (i.e., surveyed a second time after the ROI was established) to generate one or more sampling locations 203.

[62] During recovery of a fluid sample 106 (i.e., “sampling”), the system 100 approaches the ROI 202 and executes a sampling pattern 205, typically a circular pattern at the sampling location while moving fluid into the sample path 108 (e.g., by activating a propagator 109). Depending on the volume of the sample bottle 107, the device 101 will sample for a period of time; for example, 90 seconds for 1 -liter sample bottles 107. Once the sampling pattern 205 is completed, the device 101 resumes the survey pattern 204, either at its current location or at the last location the survey pattern 204 was overridden or moves on to the next logged ROI 202 or sampling location 203 for additional sampling.

Method of use

[63] Several exemplary methods of use of the instant invention is now described herein. A system 100 is described herein, the system 100 having a device 101 comprising a host 102 and an assessment payload 103 for detecting and sampling an analyte in a fluid body 105. The assessment payload is typically prepared at a base station 131 in a suitable service cradle 123. The base station 131 may be any suitable location. In some methods and uses, the base station 131 is a dock facility at the edge of the fluid body 105. In other methods and uses, the base station 131 is a surface vessel in the fluid body 105, often close to the survey area 201. Typically, the assessment payload 103 is attached to the host 102, then the sampler 104 is loaded into the assessment payload 103. Typically, sample bottles 107 are loaded into samplers 104 before the samplers 104 are loaded into the assessment payload 103. Next, the cover 112 is fastened to the assessment payload 103, and the device 101 is deployed or otherwise placed into the fluid body (step 602 in FIG. 6). In many cases, device 101 will have to move or otherwise traverse the fluid body 105 (depicted as arrow 603 in FIG. 1A) to arrive at the survey area 201.

[64] Once in the fluid body, the device 101 conducts the survey method 200 and is typically pre-programmed to perform a survey pattern 204 along with a pre-programmed sampling algorithm 206 (step 604). In some methods, the survey pattern 204 and sampling algorithm 206 are updated by the base station 131 in real-time, or are autonomously adapted by device 101 based on sensor readings (i.e., sensor information 136). In most methods, the sampling trigger and sampling algorithm are suspended or otherwise inactivated while device 101 is traveling to and from the survey area 201. While the device 101 is traversing the survey pattern 204, the onboard sensors 114 are active and report sensor information 136 to the controller 116 (step 606). The sensor information 136 informs the controller 116 when to assign a sampling location 203; typically when a sampling trigger 209 condition is met. Device 101 determines if the sampling trigger 209 is met (step 608). If the sensor information 136 is below the sampling threshold, device 101 continues the survey pattern (stop 610). If sensor information 136 is above the sampling threshold, device 101 designates either a ROI 202 or a sampling location 203 (step 612).

[65] In one method, the sampling locations are logged for later sampling 207, and device 101 continues surveying the survey pattern 204 (step 616). In other methods, device 101 breaks away from the survey pattern 204 (step 618) and sampling 207 occurs at the sampling location 203 or ROI 202. To sample, controller 116 activates the sampling pattern 205 and a propagator 109 to take a fluid sample 106 when device 101 is sufficiently close to the sampling location 203 (steps 620 and 622). Before the device 101 breaks away from the survey pattern 204 to sample 207 a general ROI 202 or an exact sampling location 203, the last surveyed location 208 is typically logged such that device 101 can resume the survey pattern 204. After sample recovery, if the survey pattern 204 is not finished, device 101 will continue traversing the survey pattern (steps 624 and 610). Otherwise, device 101 will move on to additional logged ROIs for additional sampling (step 626). If there are no additional ROIs or sampling locations to be sampled, device 101 will travel back to the base station 131 for device recovery (step 628).

[66] In methods that sample during the survey period, device 101 will complete the survey pattern 204 before returning to the base station 131 for sample bottle removal. The assessment payload 103 is disassembled (i.e., each cover 112 is removed and samplers are unfastened), samplers are removed from assessment payload 103 and placed onto a service cradle 123 (step 632). Typically, filled sample bottles 107 (either filled with samples 106 or a blank) are removed from the samplers 104, closed (e.g., capped), identified (i.e., barcoded), placed on ice (step 634), and shipped to an analytical laboratory (step 636).

[67] In methods that sample after the survey pattern 204 is completely traversed, device 101 will then go to each logged sampling location 203 and conduct its sampling algorithm 206 in order to obtain fluid samples 106. Once sampling 207 is complete, device 101 then returns to the base station 131.

[68] After sampler 104 removal, the device 101 may be refitted with clean samplers 104 along with clean inlet tubes 117, and new, clean sample bottles 107 for device 101 redeployment. The entire sample path 108 may be replaced with clean parts, or only a subset of sample path 108 components may be replaced with clean parts before redeployment. Preferably, the device 101 itself is also decontaminated. In the methods disclosed herein, the base station 131 may be distant from the survey area 201. While transiting to and from the survey area 201, device 101 may record sensor information 136, or may turn off sensors 114 to save power. If sensors 114 are active, device 101 may be programmed to override its sampling trigger 209, such that the sampling algorithm 206 is not activated during transit.

Example

[69] One specific embodiment of the present invention is now described herein. In this embodiment, one specific host 102 and other elements are described in detail. It is to be understood that this example is one solution solved by the present invention and is not limiting to the overall invention described herein. In this example, the host 102 comprised a REMUS 600 AUV that contained an oil assessment payload 103. The REMUS 600 was chosen because it is large enough to comfortably accommodate several 1 liter bottles, along with other sensors, within its 32 cm diameter. The REMUS-600 is a member the REMUS family of AUVs, which includes the smaller REMUS- 100 and the larger REMUS-6000 autonomous underwater vehicles, all developed at Woods Hole Oceanographic Institution and commercially available by Hydroid Inc.

[70] The REMUS-600 is a general purpose autonomous underwater vehicle which operates to 600m depth. With 3m length, 300 kg mass, and 5 kWh battery energy, expandable to 15 kWh, its rear half implements core vehicle control, propulsion, navigation, and communication functions, while its forward half is a reconfigurable payload section that can accommodate a variety of mission-specific payloads. The REMUS-600 is well suited for 1-2-day search and survey operations employing payloads requiring up to 200 W power.

[71] Payloads are attached to the host 102 vehicle using a joiner 111 comprising a 32 cm diameter ring joints and use the supported host electrical connection 110 interfaces which, in this embodiment, include five RS-232 serial, five gigabit ethernet ports, and five each switchable 12 VDC and 28 VDC power supplies.

[72] Assessment payload 103 configuration. For oil response and assessment, the REMUS-600 host vehicle 102 was configured with an assessment payload 103 comprising several in situ hydrocarbon sensors along with the newly developed sampler 104. The assessment payload 103 includes a Licor LI- 102 PAR in situ optical sensor 114 measuring downwelling sunlight, a Seabird Sea-OWL sensor 114 having three independent optical channels for simultaneous measurement of FDOM, CDOM, and chlorophyll, and an Anderaa 483 IF optode sensor 114 that measures oxygen concentration. FDOM sensor information is illustrated in FIG. 4B as grey scale concentration along device 101 path (y-axis depth and x- and z-axis latitude and longitude) as well as FIG. 4C as recorded over time. Additional sensor data are illustrated in FIGS. 4D-4H, showing controller 116 determined droplet count (140 counted in FIG. 4D), droplet radius (median of 19.86, FIG. 4E), droplet opacity where a value of 1 is completely opaque (median opacity of 0.077067 in FIG. 4F), droplet volume sum in micrometres cubed (3,819,670.79, FIG. 4G) and temperature (15.23, FIG. 4H).

[73] Forward of the optical sensors are two samplers 104 of the newly developed system 100, each sampler 104 containing six 1-liter bottles, for a total of 12 bottles in the device 101. In this embodiment, visual sensors comprising at least one standard underwater camera is used to record oil bubbles and droplets. The standard underwater camera is located front of the sampler sections 104a, 104b. A Seascan Holocam sensor captures a 3 -dimensional holographic image, illustrated in FIG. 4A of an 11 cm column of undisturbed of water between two probes in front of the device 101 and its sensor information can be used by the controller 116 to measure oil droplet size distributions. A forward-facing GoPro Hero 3 video camera captures continuous video.

[74] Operation. The inventive sampler 104 was designed for clean sampling of hydrocarbons. Design choices, including sample volume, materials in contact with sample 106, and sample path 108, were all chosen to minimize contamination of the samples 106. The sample volume of 1 liter was chosen in this embodiment to allow typical detection limits: typically, 0 8pg/L for alkanes and 0.05 pg/L volatile organic compounds (VOCs) with lower limits for PAH and biomarkers. Here, the sample bottles 107 comprise glass bottles that were used instead of tougher and more-buoyant alternatives, because glass is hydrocarbon-clean. In fact, the only materials in the sample path 108 other than the glass bottle are 316 stainless steel and fluoropolymers (PFPE, FKM and PTFE), to minimize hydrocarbon contamination.

[75] Sample paths 108 for each bottle are completely independent to minimize cross contamination between samples 106. Inlet tubes 117 are upward facing, extending beyond the device 101 envelope (i.e., the upper limit of any device 101 component, especially the cover 112) to avoid sampling fluid that has been in contact with the device’s exterior surfaces, which may be contaminated with hydrocarbons during surveying. After recovery of the REMUS-600 AUV, sample bottles 107 may be quickly removed from the samplers 104a, 104b and shipped to an analytical laboratory.

[76] Implementation and Fabrication. In this embodiment, the sampler 104 further comprises several subassemblies, relying on many commodity parts combined with a few specialized parts fabricated using rapid prototyping. Single-use wide-mouth pre-cleaned amber glass sample bottles 107 are used to store water samples 106. Interchangeable bottles are commercially available from several vendors. Bottles are certified by the vendor to meet EPA standards (EPA 1992), with negligible amounts of semi-volatile organics and other contaminants. Fluid enters each bottle through a 15 cm long, 12 mm diameter PTFE inlet tube 117, which are resilient against accidental impacts during launch and recovery of the AUV. These inlet tubes 117 are designed to be replaceable to prevent cross-contamination, preferably after each recovery.

[77] Next, fluid flows through an upstream check valve 118 and into the sample bottle 107 via the bottle adaptor 120. Check valves (Swagelok SS-4CP6-1/3-SC11) trap water in the bottle and prevent water exchange with the environment when the pump 109 is not operating. Each stainless- steel check valve contains FKM O-rings lubricated with Krytox fluoropolymer grease.

[78] In this case, bottle adaptors 120 are cylindrical plugs made of stainless steel with radial FKM O-rings that seal inside the neck of the glass bottles. The bottle adaptor 120 assembly includes a stainless-steel fill tube 127 inside the bottle 107 to promote complete filling from bottom to top and help purge bubbles at the top. A second downstream check valve 121 is connected at the outlet port 126 of the bottle adaptor 120. The downstream check valve 121 is terminated with a brass 90° elbow, and a silicone elbow connects from the brass elbow to the pump inlet.

[79] Each sample bottle 107 has a separate pump (i.e., the propagator 109) to pull pre-fill water out of the bottle during sampling and to replace it with a fluid sample 106. Submersible impeller pumps are made by Shenzhen Century Zhongke Technology Co., model DC-40 A. Pumps are made of hydrocarbon thermoplastics, but because they are located downstream of the sample bottle 107, beyond the downstream check valve 121, the pump 109 is not in the sample path 108 and need not be completely free of hydrocarbons. Pumps are submersible, sealed against water ingress, and potted without voids for pressure tolerance.

[80] In this embodiment the controller 116 comprises a printed circuit board assembly (PCBA) having a supervisory microcontroller, and controls six pumps, cycling them on for a specified time, and provides diagnostic information including temperature, ground fault detection, and the amount of power consumed by each pump. The PCBA accepts a power supply of 18-36V from the host 102 and communicates with the host 102 by an RS-232 connection (via host connection 110).

[81] The central junction-box sub-assembly 115 incorporates six pumps, control PCBA and all electrical wiring, sealed together in cast polyurethane within a thin plastic shell. The shell is composed of Acrylonitrile Styrene Acrylate (ASA) filament, formed by fused deposition modelling (FDM). Pump housings are first sandblasted to improve adhesion to polyurethane, and then inserted into circular openings in the shell. Cyanoacrylate glue fastens pumps to the hollow shell and prevents later leakage of polyurethane. Next, the uplink cable is soldered to the PCBA, which is placed into the shell, and pump wires are soldered to the PCBA within the shell.

[82] Polyurethane (3M Scotchcast flame retardant polyurethane 2131) is next poured into the shell, degassed under vacuum and cured overnight. After curing, the polyurethane sprue is sawed off and deburred. The potted pump assembly and six bottle-adapter assemblies are all attached to an anodized aluminum plate, with handles to facilitate installation of the 6-bottle module into the host 102 AUV.

[83] Each six-bottle sampler 104 is placed in a strong aluminum frame which is attached to the host 102 using 32 cm diameter ring joints. Buoyancy mechanisms, here yellow-painted syntactic foam blocks, are attached to the frame, surrounding the sample 106 bottles. These foam blocks protect the fragile glass bottles, streamline the host 102 and offset the weight of sampler 104 and frame. More than one sampler 104 frame may be mounted on a host 102 at the same time, allowing 6, 12, or 18 samples to be collected during a single mission.

[84] Operational Sequence. To obtain device 101 neutral or near neutral buoyancy, bottles must be pre-filled with fluid, typically water. Before loading a sampler 104 onto the host 102 AUV, distilled water is pumped into each bottle by temporarily connecting a flexible tube from the distilled water supply to each inlet barb 119 of the upstream valve 118.

[85] One or more samplers 104 are loaded onto the REMUS host vehicle 102 and new inlet tube 117 extensions are attached to each inlet barb 119. The device 101 is then is ready to launch. After launch and during sampling, when a propagator 109, here a pump, is activated by the controller 116, ambient seawater flows into one sample bottle 107, passing through the inlet extension, upstream check valve 118, and fill tube 127. After the device 101 is recovered, sampler 104 modules of six bottles each are easily removable from the host 102 for fast access to sample bottles 107. To remove filled bottles, in this embodiment, first four screws (fasteners 129) are removed with the top foam block. Four more screws hold the sampler 104 in place (fasteners 130). The umbilical cable, Subconn MCIL8M, is disconnected from the host, and then the sampler 104 may be removed and placed in its service cradle 123. The bottles, attached only by their threaded necks, can then be unscrewed, capped with PTFE-lined screw caps, labelled, and placed in coolers for transport to an analytical laboratory. No bottle-to-bottle water transfer is necessary, avoiding alterations to sample and simplifying on-site sample handling.

[86] Design Verification: pressure tolerance. Pumps were qualified for use at ambient pressure by placing a test pump in a pressure test chamber filled with mineral oil, with electrical penetrations to supply 12V power to the pump inside. The chamber was pressurized to 69 MPa with the pump operating. The pump was run for 24 hours while pressurized, with no change in power consumption. Pumping performance was satisfactory after the test. After assembly of pumps into the junction box, the complete multi -pump sampler 104 assembly was placed underwater and electrical resistance from umbilical power ground to seawater was measured with a multimeter. No ground faults were detected in any of the junction boxes tested.

[87] Design Verification: flow rate. To measure pump flow rate, a complete sampler 104 was filled with fresh water, and the inlet tube 117 was immersed in a bucket. A single pump was activated continuously. Water exiting the pump was collected in empty 1 liter bottles, which filled in 20-30 seconds. Although the maximum flow rate of the pump is advertised as 10 liters per minute, measured flow rate with check valves and other restrictions is conservatively estimated at 2 liters per minute. To ensure complete displacement of pre-fill water, pumps are run for 90 seconds for approximately three water changes.

[88] Design Verification: exchange fraction. A rigid stainless-steel fill tube 127, extending down from the bottle adaptor 120 into the sample bottle 107, promotes rapid and complete exchange of water by guiding newly introduced sample water (here, seawater) to the bottom of the sample bottle 107, while displaced water exits out of the top. Tests using dye-colored water to track the exchange of water in the bottle confirmed that the fill tube enforces a more complete exchange of water for each liter pumped. A density gradient between buoyant distilled pre-fill and heavier saline sample 106 water helps keep the newly introduced seawater below and separate from the less dense pre-fill, so that the bottle is completely filled from bottom to top. To verify exchange of water, a sampler 104 was pre-filled with distilled water, placed in seawater, and each pump was commanded to pump for 90 seconds. The resulting water in the bottles contained 98% salinity of the ambient seawater, indicating very little of the original pre-fill water remained in the bottle.

[89] Design Verification: leak testing. The sampler 104 secures water in the sample bottle 107 by means of two check valves. These valves are sealed closed by springs when the pumps are off. To test the integrity of the seals, 6 bottles were pre-filled with fresh tap water, measuring less than 1 ppt salinity. The entire sampler 104 was suspended in seawater overnight. After removing sample bottles 107, salinity was measured again and remained less than 1 ppt, as illustrated in FIG. 5B, demonstrating that exchange of sample water 106 is negligible when check valves (upstream 118 and downstream 121) are sealed.

[90] Performance of the sampler 104 can be checked later in the lifetime of the sampler 104 by using distilled water for pre-fill and measuring salinity of samples. By reserving a “trip blank” bottle for this purpose and measuring the salinity of the recovered pre-fill, the integrity of the bottle seals can be confirmed during actual sampling operations.

[91] Autonomous Sampling Algorithm. Typical autonomous surveys use a grid pattern to cover an area uniformly. Inevitably there is a delay between detection of oil and collection of water. Therefore, the host 102 is programmed with a sampling algorithm 206 which may trigger sampling 207. Sampling may occur immediately, temporarily overriding the survey pattern 204 to sample 207, or a sampling location 203 may be logged for later sampling 207. The sampling algorithm 206 may be programmed such that when sensor (e.g., FDOM) measurements exceed a pre-set threshold (i.e., sampling trigger 209) for several consecutive sensing events, the location of maximum FDOM is marked for sampling 207. The host 102 then breaks away from the grid survey pattern 204, navigates back to this sampling location 203 and performs a sampling pattern 205, for exampling moving in a 10 m diameter circle while pumping water 106 into a sample bottle 107. After 90 seconds of pumping the AUV resumes the remainder of the survey method 200.

[92] At Sea Testing, Santa Barbara Oil Seeps. During field testing a WHOI team, led by Amy Kukulya, joined teams from US Environmental Protection Agency, US Coast Guard, and National Oceanic and Atmospheric Administration and Monterey Bay Aquarium Research Institute to locate, map and sample naturally occurring oil seeps near Santa Barbara, CA. During the exercise, which simulated a rapid response to an oil spill, we deployed several autonomous underwater vehicles to locate and map hydrocarbon plumes. Objectives were to locate hydrocarbon plumes in the water column, to feed near-real-time environmental sensor data into an online geodatabase, and to capture water samples for detailed hydrocarbon assessment.

[93] As part of the exercises, near-real-time AUV survey data, including FDOM, oxygen, conductivity and temperature sensor information 136 were fed into an online database. National Oceanic and Atmospheric Administration’s (NOAA) Environmental Response Management Applications (ERMA) is designed to provide centralized, easy-to-use up to date information for environmental responders and decision makers. With the AUVs surfaced between missions, sensor data was offloaded over Wi-Fi modems, processed into appropriate format and uploaded to the ERMA geodatabase.

[94] Underwater vehicle operations were conducted aboard the USCG Cutter George Cobb. A total of 8, 6-bottle sampler modules 104 were assembled, tested, and loaded onto the Cobb although not all were used. Three different AUVs with different configurations were used to map underwater oil plumes, including a Long Range AUV (LRAUV) that ran long-distance transects in the region of previously known oil seeps and surface slicks, returning FDOM profiles in order to inform sampling with REMUS AUVs (here one REMUS 600 acting as the device 101). A REMUS- 100 AUV conducted acoustic echosounder surveys which revealed buoyant plumes rising from several sources on the bottom. And the REMUS-600 vehicle conducted gridded FDOM surveys, pausing to take water samples 106 when FDOM was detected above a pre-programmed threshold. The system 100, with a device 101 comprising a REMUS-600 AUV host 102 and an assessment payload 103 comprising two samplers 104a, 104b completed 19 missions (survey methods) 200 in five days, each between 0.5 and 3 hours long, during which the samplers 104a, 104b collected 13 seawater samples 107.

[95] Sampler 104 preparation and offloading. Samplers 104a, 104b were prepared for service at a worktable (i.e., the service cradle 123) on the open deck of the USCGC Cobb (here the base station 131). Distilled water was purchased from Water Store in Goleta, CA and loaded on to the Cobb in 5-gallon polycarbonate carboys. On board the ship base station 131, this distilled water was used to pre-fill empty sample bottles 107 before loading the sampler modules 104a, 104b into the REMUS-600 AUV host 102. Each day of operations, a total of 12 bottles were loaded on the REMUS-600 AUV host 102. At the end of each day’s operations (i.e., mission 200), samplers 104a, 104b with newly captured samples 106 in sample bottles 107 were unloaded from the device 101, and bottles 107 were removed, capped, labelled, and packed in ice for shipment to the analytical laboratory.

[96] After securing the sample bottles 107, the contaminated samplers 104a, 104b were decontaminated by first scrubbing the sampler 104 in a tub of Sunshine Makers Simple Green All- Purpose Cleaner diluted 10:1, and then pumping a solution of 10:1 diluted Simple Green from a reservoir through each inlet tube 117 and propagator (here a pump) 109, with a temporary cleaning bottle installed, followed by freshwater rinse.

[97] Autonomy Configuration and Results. Sampling 207 was executed by a “take gulp” behavior (i.e., a sampling algorithm 206), which was triggered by pre-set threshold criteria during a survey 200. Threshold criteria were adjusted throughout the week based on experience with the system 100. For example, a fixed percent FDOM increase over background moving average was end result of some experimentation. The moving average was taken over either a set number of minutes or distance units.

[98] A total of 19 water sample bottles 107 were shipped to the analytical laboratory including 13 seawater samples 106. Five bottles sent for analysis were blanks, pre-filled and carried onboard the AUV during one or more missions 200 but never pumped. These bottles were known as Trip Blanks. One bottle was pre-filled with distilled water from the same source but was never loaded onto a sampler 104 and never placed into the ocean and is known as a DI (deionized water) Blank.

[99] Water Analysis Results. Water samples 106 were analyzed for total benzene, toluene, ethylbenzene, and the three xylene isomers (BTEX), total petroleum hydrocarbons (TPH), total Alkanes, and total polycyclin aromatic hydrocarbons (PAH). Overall levels of hydrocarbons were low. Total alkanes measured less than 40 pg/L. Benzene, Toluene, Ethylbenzene and Xylene (BTEX) were less than 400 ng/L, both considered safe levels in drinking water by the US EPA. Surprisingly, the DI Blank, which had no contact with the ocean nor with the sampler, measured the highest BTEX of any sample 106 analyzed, at 385 ng/L. The DI Blank was taken from Water Store distilled water and was stored in plastic carboys for a few days before use aboard USCGC Cobb base station 131. Plastic storage tanks and bottles may have been the source of these small concentrations of hydrocarbons. Consistent with the DI Blank, Trip Blanks, derived from the same source of distilled water, also measured more BTEX than the ocean water samples, 243-334 ng/L. This unexpected result highlights the difficulty of maintaining water free of hydrocarbons when it is stored in contact with plastic and confirms the need for a hydrocarbon-free sample path 108. [100] Underway Leak Test. All ocean water samples measured 35-37 parts per thousand salinity, as expected for seawater with negligible dilution. Trip Blanks measured 1-2 ppt salinity indicating a small but measurable ingress of ocean water into the pre-filled sample bottles 107. These five trip blanks had been immersed for 5-9 hours each and travelled between 25-42 km while installed in the device 101 during surveys 200. The Trip Blank salinity variability of 1-2 ppt is not correlated with total deployed time or distance travelled, so water ingress may be due to residual air bubbles in the sample bottle 107. Any residual air volume will collapse at depth, forcing seawater to enter sample bottle 107 through the upstream check valve 118.

[101] Decontamination Residue. The samplers 104 were numbered, and Sampler number 4 was re-used after Simple Green site decontamination. Samples 106 captured from one sampler 104 provide a measure of hydrocarbon residues introduced by the site decontamination procedure. The two seawater samples 106 and one trip blank offloaded from the decontaminated sampler 104 showed no apparent increase in hydrocarbons compared to other samples and blanks, suggesting that the decontamination procedure does not introduce additional hydrocarbons into the samples 106. Additional testing will be needed to show that the decontamination procedure is adequate reuse of a heavily oiled sampler 104.

[102] The Santa Barbara oil seeps were found to have intermittent, low-volume flow, making it difficult to plan targeted survey missions. It was valuable to have multiple sensor platforms active including aerial vehicles, and long-range AUVs in the water, both of which provide real-time wide- area situational awareness.

[103] Autonomous triggering of water samples was also challenging in this environment, with unpredictable min and max fluorescence range. The difficulty of autonomous triggering (i.e., thresholding) was highlighted during a long transit at constant depth in which the highest fluorescence, when no oil was expected, sample trigger 209 (to recover a fluid sample 106) was disabled during this segment of the mission, and no fluid sample 106 was collected.

[104] Finally, contamination of samples was a persistent threat. Hydrocarbons are all pervasive. Despite design choices and procedures to minimize contamination, contamination may determine the lower detectable limits for some compounds. With higher concentrations of oil which would occur in an oil spill, this may be less of a limitation.

[105] Oil spills are transient events that can have a long-lasting impact to the ocean environment. Sampling an underwater hydrocarbon plume in the open ocean is difficult due to restricted access and transport of water away from the plume source. The assessment payload 103 used herein is designed to rapidly detect hydrocarbons and then immediately capture water in quantities sufficient for hydrocarbon analysis, while maintaining the independence and integrity of multiple samples 106. By triggering sampling only when hydrocarbons (i.e., analytes) are detected, the time and expense of analysis is incurred only when samples 106 are likely to contain valuable information about the hydrocarbon plume. Seep and spill assessments can return more information in a shorter time and with less effort.

[106] Although specific features of the present invention are shown in some drawings and not in others, this is for convenience only, as each feature may be combined with any or all of the other features in accordance with the invention. While there have been shown, described, and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions, substitutions, and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is expressly intended that all combinations of those elements and/or steps that perform substantially the same function, in substantially the same way, to achieve the same results be within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale, but that they are merely conceptual in nature. [107] It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. Other embodiments will occur to those skilled in the art and are within the following claims.

Claims

Claims

1. A device for analyzing and sampling a fluid body comprising: an assessment payload comprising: a first inlet tubing, a first upstream valve connected to said first inlet tubing, a first bottle adaptor connected to said first upstream valve, and a first propagator connected to said first bottle adaptor; a first sample bottle reversibly fastened to said first bottle adaptor and configured to store a fluid sample; wherein said first propagator is configured move fluid from a fluid body through said first inlet tubing, said first upstream valve and said first bottle adaptor into said first sample bottle; a first sensor configured to produce sensor information; a controller electronically connected to said first sensor and said first propagator; wherein said controller is configured to (i) receive said sensor information and determine a first parameter relating to said sensor information and to (ii) activate said first propagator.

2. The device of claim 1 wherein said assessment payload further comprises: a second inlet tubing, a second upstream valve connected to said second inlet tubing, a second bottle adaptor connected to said second upstream valve, and a second propagator connected to said second bottle adaptor; a second sample bottle reversibly fastened to said second bottle adaptor and configured to store a second fluid sample; wherein said second propagator is configured move fluid from said fluid body through said second inlet tubing, said second upstream valve and said second bottle adaptor into said second sample bottle; wherein said controller is electronically connected to said second propagator and is configured to activate said second propagator.

3. The device of claim 2 wherein said first and said second inlet tubing, said first and said second upstream valves, said first and said second bottle adaptors, said first and said second propagators, and said first and said second sample bottles are within a sampler and wherein said sampler is located within said assessment platform.

4. The device of claim 3 wherein said sampler is reversibly connected to said assessment payload.

5. The device of claim 1 wherein said controller is configured to (i) establish a first region of interest relating to said sensor information; and to (ii) activate said first propagator when within said first region of interest.

6. The device of claim 5 further comprising a host connected to said assessment payload and electronically connected to said controller; wherein said host is configured to move through said fluid body, and said controller is configured to instruct said host to move to said first region of interest.

7. The device of claim 1 wherein said first inlet tubing, said first upstream valve, said first bottle adaptor and said first sample bottle have negligible amounts of semi-volatile materials.

8. The device of claim 1 wherein said controller is located within said assessment payload.

9. The device of claim 1 wherein said assessment payload further comprises a cover having a first slot; wherein said cover is configured to reversibly fasten to said assessment payload and said first inlet tubing is configured to pass through said first slot.

10. A method for analyzing and sampling in a fluid body, comprising the steps of:

(a) providing a device comprising an assessment payload, a first sensor, a controller, and a first sampler having a first sample bottle and a first sample path comprising a first inlet tubing, a first upstream valve, a first bottle adaptor, and a first propagator; wherein said first sample bottle is configured to store a fluid sample from the fluid body; said first sensor is configured to produce sensor information; and said controller is connected to said first sensor and said propagator;

(b) moving said device through a survey area in a fluid body and producing sensor information relating to an analyte with said first sensor;

(c) designating, with said controller, a first region of interest relating to said sensor information in said survey area; and

(d) activating said first propagator to take a first fluid sample using said first sample path.

11. The method of claim 10 wherein step (d) occurs at said first region of interest.

12. The method of claim 10 further comprising the step of (e) designating a second region of interest relating to said sensor information in said survey area.

13. The method of claim 12 further comprising the steps of:

(f) comparing, with said controller, said sensor information in said first region of interest with said sensor information in said second region of interest; and

(g) choosing a region of interest to activate said first propagator in step (d).

14. The method of claim 10, wherein said first sampler further comprises a second sample bottle and a second sample path comprising a second inlet tube, a second upstream valve, a second bottle adaptor, and a second propagator.

15. The method of claim 14, further comprising the step of (h) activating said second propagator to take a second fluid sample using said second sample path.

16. The method of claim 15, further comprising the step of (i) designating a second region of interest relating to said sensor information in said survey area; and wherein step (h) occurs at said second region of interest and after step (i).

17. The method of claim 10, further comprising the step of (j) placing said device in a fluid body; and wherein step (j) occurs before step (b).

18. The method of claim 10 wherein said first sample path connects to no other sample bottles.

19. The method of claim 10 wherein said first sample path and said first sample bottle have negligible amounts of semi-volatile materials.

20. The method of claim 10 further comprising the steps of:

(k) removing said device from said fluid body;

(l) removing said first sample bottle from said device;

(m) attaching a clean sample bottle onto said first bottle adaptor; and

(n) placing said device into said fluid body.