RU2315976C1 - Multi-sensor device for analysis of multi-component aqueous media - Google Patents

Abstract

FIELD: devices and processes for analysis of aqueous media.

SUBSTANCE: device includes set of selective sensing members and converter of analytical signal of response of said sensing members. Selective sensing members being test-forms on base of selective chromogenic analytical reagents applied onto solid carrier and they are placed in cartridge. In order to convert analytical response signal, portable scanning module controlled by personal computer is used. Number of selective sensitive members of such device depends upon number of components to be analyzed.

EFFECT: possibility for simultaneous determination of different matter concentration in multi-component aqueous medium.

4 cl, 1 dwg

Description

The invention relates to the field of analytical chemistry and can be used to create high-speed portable portable devices for the detection and identification of chemicals in the aquatic environment.

The need for such devices has now increased tremendously, especially for environmental and toxicological control and monitoring.

In recent years, compact devices for monitoring various technological processes and the environment based on chemical sensors, characterized by high speed, sensitivity and specificity, have become widespread. The most widely used sensors are metal oxide sensors, conductive polymers, piezocrystalline and optoelectronic sensors, catalytic transistors, the operating principles of which are based on measurements of conductivity, mass increment, measurement of capacitive charges, optical parameters, etc. Such sensors allow you to detect a large number of chemicals in the environment and almost the entire range of priority toxicants.

The principal tasks facing developers of sensor devices are to increase their sensitivity and selectivity with respect to individual substances.

It should be emphasized that sensory devices designed for the analysis of air and water environments differ significantly in the physicochemical principles underlying them.

The most common and effective type of sensors for aqueous solutions are electrochemical sensors based on potentiometric methods of analysis. Currently, the development of a multisensor system using an array of chemical sensors (ion-selective electrodes) and artificial neural networks for the quantitative analysis of multicomponent aqueous solutions (Yu.G. Vlasov, A.V. Legin, AMRudnitskaya, K.Di Natale, A.D. Amiko, Multisensor system using an array of chemical sensors ("electronic language") and artificial neural networks for the quantitative analysis of multicomponent aqueous solutions. Journal of Applied Chemistry, 1996, V.69, Issue 6, pp. 958-964 ) However, this method has certain disadvantages. The mentioned electrodes in the full sense of the word cannot be called highly selective, since all types of ions contribute to electrical conductivity and electric potential. In this regard, it is precisely because of the cross sensitivity of the sensor system that there is a need to subject experimental data (electrode potentials) to modern mathematical processing (neural network method) in order to obtain more reliable values of ion concentrations.

This known method cannot be used to detect and identify a pre-specified substance, especially organic nature, located in an unpredictable environment of unknown composition, without first calibrating the entire solution. In other words, the presence of cross sensitivity (poor selectivity) makes it very difficult or even impossible to identify and measure the concentration of the problematic substance in any a priori unknown medium.

A known method for the detection of chemicals in the aquatic environment by measuring the residual magnetic induction (RU 2175136, G01N 33/543, G01N 33/532, 10.20.2001). In this method, a quantitative analysis of chemicals in the liquid phase is carried out by measuring the residual magnetic induction of binding using compounds suitable for this. First, substances with a specific structure are labeled with ferrimagnetic or ferromagnetic substances, and then these magnetically labeled substances with a specific structure are added to the measured sample, the measured sample is magnetized using an external magnetic field, and after the external field is turned off, the residual magnetic induction is measured with using magnetic field sensors, the residual magnetic induction resulting from specific binding is measured.

The disadvantages of this method are the need for preliminary labeling of substances with a specific structure of ferri- or ferromagnetic labels, which complicates the already laborious measurement procedure.

In the patent RU 2263904, G01N 27/00, 10.11.2005 a sensor for antioxidants is described, which is a one-time device for detecting the presence or absence of a redox reactive analyte in an aqueous sample. The device is an electrochemical cell having a sensor chamber, a first electrode, a second electrode, an opening for introducing a sample into the sensor chamber, and a reagent contained within the sensor chamber. The electrochemical cell is designed to be replaceable after use in one single experiment. In this case, the reagent is capable of undergoing a redox reaction directly with the analyte with the generation of an electrical signal indicating the presence or absence of the analyte.

An obvious disadvantage of the device is the fundamental impossibility of creating on its basis a multisensor system for the analysis of a multicomponent aqueous solution. In addition, on the basis of such sensors it is impossible to construct a small-sized sensor device.

Known fluorescent sensors for the analysis of multicomponent aqueous media based on multichannel structures. In the patent US 6023540, MKI G02B 6/26, NKI 385/12, 08.02.2000 describes a sensor obtained by sintering a beam of a large number of fiber optic filaments, each of which consists of two coaxial layers. The inner layer of each strand is etched to a shallow depth where microspheres of the solid sorbent are placed. In patent RU 2252411, G01N 21/64, G01N 23/223, 05.20.2005, the multichannel structure of the fluorescent sensor is a segment of a multicapillary tube with through capillaries forming microchannels that are filled with two layers of immiscible substances. One layer is formed by water or an aqueous solution, and the other is organic matter. Sorbent microgranules are placed in the microchannel water layer. In this device, the microspheres of the sorbent act as a concentrator of the analytes. The concentration of the analytes is determined using x-ray fluorescence or luminescent spectral methods, which in this case play the role of a transducer (converter) of the primary signal of the sensing element. In this multisensory system, filled capillaries play the role of sensitive elements. The characteristic times of analysis of aqueous solutions using this system are tens to hundreds of minutes, which makes it possible to determine very low concentrations of analytes that are not available with direct analytical control by x-ray fluorescence.

The main disadvantages of multichannel fluorescent sensors are the complex technology of their manufacture and the need to use bulky and expensive instruments such as a luminescent spectral analyzer or an X-ray fluorescence analyzer, which serve as transducers (converters) of primary signals of concentration-sensitive elements. The disadvantage is the long analysis time (tens to hundreds of minutes). In addition, the measurement procedure is quite complicated and requires special skills and highly qualified staff.

Closest to the proposed device is a multisensor device for the analysis of multicomponent aqueous or gaseous media, which is a matrix piezosorption detection cell described in patent RU 2212657, G01N 27/12, 09/20/2003 (prototype). The piezosorption detection cell consists of a body with two nozzles (one for injecting a liquid sample to be analyzed, the other for a gaseous one, if one of the nozzles is not in operation, it is closed by an airtight plug), inside of which (on the housing cover) there is a set of six piezosensors with sensitive selective sorption-type film coatings, and devices for exciting oscillations and for recording and converting the analytical signal of the responses of piezosensors. A microcircuit is connected to the cover of the detector housing to control the generation of oscillations and fix the primary response signals of the sensitive elements, which are transmitted to the computer and are calculated according to a certain algorithm. The input of the analyzed sample is carried out in static conditions.

The disadvantages of the prototype device are the complexity and high cost of manufacturing selective concentration-sensitive elements placed in a piezosorption cell, as well as their limited number (six sensors). In addition, preparing the system for repeated measurements by regenerating sorption films on piezoelectric sensors, for example, rinsing with clean water, if possible, takes too much time. The replacement of piezosensors with new ones leads to a significant increase in the cost of analysis. In addition, the procedure for taking measurements and making decisions is rather complicated and requires special skills and highly qualified operators.

The objective of the invention is the development of such a highly selective multi-sensor device for the analysis of multicomponent aqueous media, which will achieve the technical result, which consists in simplifying and cheapening the manufacturing technology of the multi-sensor device, in almost unlimited increase in the number of analyzed components in aqueous solutions and in simplifying the measurement procedure that does not require special skills and highly qualified staff.

The solution of this problem is achieved by the proposed multisensor device for the analysis of multicomponent aqueous media containing a set of selective sensitive elements and an analyzer of the analytical response signal of the sensitive elements, in which the selective sensitive elements are test forms based on selective chromogenic analytical reagents placed in a cartridge configured to exposure in the analyzed aqueous medium, and the number of test forms in the cartridge matches the number Twomey substances defined in multicomponent aqueous medium.

The selective chromogenic assay reagent in the test form can be applied to a solid carrier, which can be made on the basis of non-woven material, paper or fabric.

A portable scanning module controlled by a personal computer can be used as a converter of the analytical response signal of the sensitive elements.

Test forms containing selective chromogenic analytical reagents are arranged in a cartridge, and the number of test forms in the cartridge coincides with the number of substances (analytes) determined in a multicomponent aqueous medium. Each test form strictly corresponds to a specific analyte. The cartridge for test forms is made of a polymer film which is semi-permeable in an aqueous medium. The test cartridge is for single use only. It should be noted that the procedure for manufacturing chromogenic test forms, which consists in impregnating solid carriers with solutions of chromogenic analytical reagents and further drying, can be easily and quickly performed in ordinary chemical laboratories by unskilled personnel.

As an example, the table shows some of the chromogenic analytical reagents in comparison with the corresponding standard priority pollutants of aqueous media of the list RD 52.04.253-90 of hazardous chemicals (AHOV) approved by Roshydromet.

Table. No. Analyte (ion) Chromogenic Analytical Reagents one Aluminum Eriochromcyanin P or chromazurol C 2 Ammonium Nessler's reagent or salicylic acid + chloramine B 3 Benzpyrene Intrinsic luminescence four Iron o-phenanthroline or tripyridyl triazine 5 Copper Zinc cuprizone or diethyldithiocarbamate 6 Arsenic Tetrazolium salts 7 Oil products Formazan 8 Nitrates Reducers based on zinc dust. Reagents based on chromotropic acid or N, N-diethyl1-aminonaphthalene 9 Nitrite Reagents based on chromotropic acid or N, N-diethyl1-aminonaphthalene 10 APAV * Basic dye eleven KPAV ** Acid Triphenylmethane Dye 12 Lead Arsazen, PAN 13 Sulphates Complexes of barium with azo dyes (beryllon (II) and analogues) fourteen Phosphates Molybdates of organic bases fifteen Chlorides Complexes of mercury with chromogenic reagents 16 Phenols 4-aminoantipyrine in the presence of an oxidizing agent 17 Fluoride Complexes of zirconium and gallocyanine or azo dye eighteen Sulfides N.N-diethylparadimethylaniline 19 Chromats Diphenylcarbazide twenty Zinc Azo dyes (PAR, sulfarsazen) * APAW - anionic surfactant. ** KPAV - cationic surfactant.

The proposed multisensor device consists (see drawing) of chromogenic test forms (1) placed in a cartridge (2), a portable scanner (4) and a personal computer (5).

The work of the proposed device is as follows.

The cartridge (2) is refilled with pre-prepared chromogenic test forms (1), selected for a set of chemicals, the detection and measurement of concentrations of which in the aquatic environment is assumed. The cartridge with the test forms is exposed in the analyzed aqueous medium, and then to measure the changes in the colorimetric characteristics (3) of the test forms, it is placed on the glass of the scanner flat table (4). If necessary, a reference color scale is placed on the glass of the tablet table, the parameters of which can also be pre-entered into the computer's memory. In the scanner, the primary conversion of color information occurs, after which the data is transmitted to a computer (laptop) (5). Using a computer, the operation of the scanning module is controlled, information is read from it, its mathematical processing and output to a display, printer (6) or information carriers (7) in the form of final analysis results. The duration of the analysis does not exceed several minutes.

Thus, the proposed multi-sensor device is highly selective - it allows you to simultaneously determine with high accuracy the concentration of a large number of different substances in a multicomponent aqueous medium, it is characterized by the simplicity and low cost of its manufacture, simplicity and ease of analysis procedure, which does not require special skills and highly qualified staff. The duration of the analysis does not exceed several minutes. The number of selective sensitive elements in the device, taking into account their easy replaceability and low cost, is not limited and depends only on the number of analyzed components.

Claims (4)

1. A multisensor device for the analysis of multicomponent aqueous media, containing a set of selective sensitive elements and an analyzer of the analytical response signal of the sensitive elements, characterized in that the selective sensitive elements are test forms based on selective chromogenic analytical reagents placed in a cartridge configured for exposure in the analyzed aqueous medium, and the number of test forms in the cartridge matches the number of substances defined in the multicomponent nt aqueous environment. 2. A multisensor device for analyzing multicomponent aqueous media according to claim 1, characterized in that the selective chromogenic analytical reagent in the test form is applied to a solid carrier. 3. A multisensor device for analyzing multicomponent aqueous media according to claim 2, characterized in that the solid carrier in the test form is made on the basis of non-woven material, paper or fabric. 4. A multisensor device for analyzing multicomponent aqueous media according to any one of claims 1 to 3, characterized in that a portable scanning module controlled by a personal computer is used as a converter of the analytical response signal of the sensitive elements.