CN115684045A - Spectrophotometer-based method and system for inherent optical measurement of spherical phaeocystis fuscus capsule - Google Patents
Spectrophotometer-based method and system for inherent optical measurement of spherical phaeocystis fuscus capsule Download PDFInfo
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Abstract
The invention discloses a spectrophotometer-based method and a system for inherent optical measurement of a spherical phaeocystis fuscus capsule body, wherein the method comprises the following steps: placing a first cuvette arranged on a fixed frame into an integrating sphere detector of a first spectrophotometer to carry out absorption measurement to obtain an absorption coefficient a (lambda); performing attenuation measurement by using an integrating sphere detector of a second spectrophotometer to obtain an attenuation coefficient c (lambda) while performing absorption measurement on the phaeocystis globosa capsule; obtaining a scattering coefficient b (λ) = c (λ) -a (λ); placing the third cuvette in a reflection window of an integrating sphere detector of a third spectrophotometer to perform backscattering measurement to obtain a backscattering coefficient b b (lambda). The invention can obtain the inherent optical characteristics (absorption and dispersion) of the spherical phaeocystis globosa capsule body while effectively protecting the spherical phaeocystis globosa capsule body structureRadiation and backscatter).
Description
Technical Field
The invention relates to the technical field of spherical phaeocystis capsule body measurement, in particular to a spectrophotometer-based method and a system for inherent optical measurement of a spherical phaeocystis capsule body.
Background
Globosas globosa (p. Globosa) frequently burst algal blooms in coastal waters of China in recent years, becoming one of the main Harmful Algal Blooms (HABs) that harm coastal waters of China. The occurrence of algal bloom is mainly large colloidal capsules, the maximum diameter of the capsules even exceeds 3cm, and further the safety of a coastal nuclear power cold source is seriously threatened. The development of a rapid and efficient monitoring means for the algal blooms, in particular a remote sensing monitoring technology with the advantages of large area synchronization, no need of sampling measurement and the like, has undoubted great significance. The inherent optical characteristics of the spherical phaeocystis globosa capsule are the important basis for analyzing the remote sensing detection mechanism, but are limited by the reasons of the special life form of the phaeocystis globosa, the uneven space-time distribution of the capsule, the low indoor culture cyst formation rate and the like, and the knowledge about the remote sensing mechanism is quite deficient. The traditional quantitative filtering membrane technology and the commercial inherent optical measuring instrument can cause the capsule body to be broken during measurement, thereby causing measurement errors.
Disclosure of Invention
The invention mainly aims to provide a spectrophotometer-based inherent optical measurement method and system for a spherical phaeocystis fuscus capsule body, which can obtain the optical characteristics of absorption, scattering and backscattering of the spherical phaeocystis fuscus capsule body while effectively protecting the structure of the spherical phaeocystis fuscus capsule body.
The invention adopts the following technical scheme:
in one aspect, a spectrophotometer-based method for measuring the inherent optical property of phaeocystis globosa capsule comprises:
putting a first cuvette arranged on a fixing frame into an integrating sphere detector of a first spectrophotometer to carry out absorption measurement to obtain an absorption coefficient a (lambda); a first spherical phaeocystis coerulea capsule sample is placed in the first cuvette;
performing attenuation measurement by using an integrating sphere detector of a second spectrophotometer to obtain an attenuation coefficient c (lambda) while performing absorption measurement on the phaeocystis globosa capsule; a second cuvette is arranged in a sample bin of the second spectrophotometer, and a second part of spherical phaeocystis globosa capsule sample is placed in the second cuvette;
obtaining a scattering coefficient b (λ), b (λ) = c (λ) -a (λ), based on the absorption coefficient and the attenuation coefficient;
placing the third cuvette in the reflection window of the integrating sphere detector of the third spectrophotometer for back scattering measurement to obtain the back scattering coefficient b b (λ); a third sample of spherical phaeocystis fuscus capsules is placed in the third cuvette.
Preferably, the absorption coefficient a (λ) is calculated as follows:
wherein l 1 Representing the optical path of the first cuvette; OD s Represents an absorbance value measured by an integrating sphere detector of the first spectrophotometer; OD f And expressing the absorbance value of the background reference liquid in the first cuvette.
Preferably, the first cuvette is a cylindrical quartz cuvette; the diameter of the first cuvette is 2.5cm, and the optical path is 4cm; the integrating sphere of the first spectrophotometer had a diameter of 15cm.
Preferably, the attenuation coefficient c (λ) is calculated as follows:
wherein l 2 Representing the optical path of the second cuvette; OD c Represents the absorbance value measured by the integrating sphere detector of the second spectrophotometer; OD f And expressing the absorbance value of the background reference liquid in the second cuvette.
Preferably, a black slit plate is arranged between the sample bin of the second spectrophotometer and the integrating sphere detector of the second spectrophotometer, and the forward opening angle of the black slit plate is not more than 0.23 degrees, so that the detector can only obtain transmitted light and scattered light within the forward opening angle; the integrating sphere of the second spectrophotometer had a diameter of 15cm.
Preferably, the backscattering coefficient b b The calculation method of (λ) is as follows:
R p (λ)-R f (λ)＝1-exp(-k×b b (λ)×l 3 )
wherein k is set to 1; l 3 Representing the optical path of the third cuvette; r p (λ) is the reflectance of the third spherical phaeocystis sample; r f (λ) is the measured reflectance of the background reference liquid.
Preferably, the third cuvette is a quartz cuvette; the diameter of the third cuvette is 2.5cm, and the optical path is 10cm; the front end of the third cuvette is provided with a raised hemisphere shape, and the rear end of the third cuvette is provided with black aluminum foil paper; the integrating sphere of the third spectrophotometer had a diameter of 15cm.
Preferably, the third cuvette is arranged on the base; the end of an integrating sphere detector of the third spectrophotometer is provided with a rear cover covering the base, the inner layer of the rear cover is of a honeycomb net structure, and the inner surface of the rear cover is coated with a black coating.
Preferably, the background reference solution is 0.2 μm Nuclecore TM The CDOM solution after filtration through a Polycarbonate or polyester filter.
In another aspect, a spectrophotometer-based optical measurement system for the inherent cell body of phaeocystis globosa includes:
an absorption measurement module for obtaining an absorption coefficient a (lambda) by performing absorption measurement using an integrating sphere detector of the first spectrophotometer; wherein a first sample of spherical phaeocystis fuscus capsules is placed in the first cuvette; a first colorimetric dish arranged on a fixed frame is arranged in an integrating sphere detector of the first spectrophotometer;
the attenuation measurement module is used for carrying out attenuation measurement by using an integrating sphere detector of a second spectrophotometer to obtain an attenuation coefficient c (lambda) while carrying out absorption measurement on the phaeocystis globosa capsule body; wherein, a second cuvette is arranged in a sample bin of the second spectrophotometer, and a second part of spherical phaeocystis fuscoporia capsule sample is arranged in the second cuvette; a black slit plate is arranged between the sample bin of the second spectrophotometer and the integrating sphere detector of the second spectrophotometer;
a volume scattering measurement module for obtaining a scattering coefficient b (λ) = c (λ) -a (λ) based on the absorption coefficient and the attenuation coefficient;
a backscattering measurement module for obtaining backscattering coefficient b by backscattering measurement using an integrating sphere detector of the third spectrophotometer b (λ); wherein, a third cuvette is provided with a third sample of the spherical phaeocystis fuscophyllum capsules; a reflection window of an integrating sphere detector of a third spectrophotometer, in which a base fixed with a third cuvette is placed; and a rear cover for covering the base is arranged at the tail end of the integrating sphere detector of the third spectrophotometer.
Compared with the prior art, the invention has the following beneficial effects:
(1) The method comprises the steps of placing a fixing frame fixed with a cylindrical quartz cuvette with the diameter of 2.5cm and the optical path of 4cm into an integrating sphere detector with a first spectrophotometer with the diameter of 15cm for measuring the absorption coefficient of the phaeocystis globosa capsule body, and can be better suitable for the absorption measurement of the phaeocystis globosa capsule body while not damaging the structure of the phaeocystis globosa capsule body;
(2) According to the method, the black slit plate is added in front of the integrating sphere detector of the second spectrophotometer and used for measuring the spherical phaeocystis attenuation coefficient, and then the attenuation and the absorption of the phaeocystis are subjected to difference value so as to obtain scattering, so that the measurement error is greatly reduced and the measurement precision is improved due to the arrangement of the black slit plate;
(3) According to the invention, the third cuvette is placed in the reflection window of the integrating sphere detector of the third spectrophotometer for back scattering measurement, the front end of the third cuvette is arranged in a convex hemisphere shape, the back end of the third cuvette is provided with black aluminum foil paper, the tail end of the integrating sphere detector of the third spectrophotometer is provided with the back cover, the inner layer of the back cover is arranged in a honeycomb net structure, and the inner surface of the back cover is coated with a black coating, so that the measurement has high absorption and low reflectivity, and the measurement accuracy is improved.
The above description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood, and to make the above and other objects, features, and advantages of the present invention more apparent.
The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof taken in conjunction with the accompanying drawings.
Drawings
FIG. 1 is a flow chart of a spectrophotometer-based optical measurement method of the inherent capacity of phaeocystis globosa capsules according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a first cuvette and a fixing frame according to an embodiment of the invention;
FIG. 3 is a simplified optical path diagram of an absorption measurement of the spherical phaeocystis fuscus capsule according to an embodiment of the present invention;
FIG. 4 is a graph comparing the absorption measurement method of the present invention with the conventional QFT method; wherein (a) represents the absorption spectrum measurement results of the monomer strain and the phaeocystis globosa capsule on QFT measured by the CIS method and the traditional method; (b) Representing the determination coefficients of the absorption spectrum measurement results of the two methods;
FIG. 5 is a schematic structural diagram of a black slit plate according to an embodiment of the present invention;
FIG. 6 is a simplified optical path diagram of a spherical phaeocystis capsule attenuation measurement according to an embodiment of the present invention;
FIG. 7 is a graph showing the absorbance contrast of the same sample measured by a first spectrophotometer and a second spectrophotometer; wherein (a) represents a first measurement; (b) represents a second measurement;
FIG. 8 is a schematic of the refractive index of the particles; wherein (a) represents a standard particle size distribution; (b) represents a refractive index; (c) represents a refractive index of pure water;
FIG. 9 is a comparison of the measured volume scattering of the standard particle (4K-02) and the Mie theoretical calculation;
FIG. 10 is a schematic structural diagram of a third cuvette and a base according to an embodiment of the invention;
FIG. 11 is a schematic structural view of a rear cover of an integrating sphere of a third spectrophotometer according to an embodiment of the present invention;
FIG. 12 is a simplified optical path diagram of a back scattering measurement of phaeocystis globosa capsules according to an embodiment of the present invention;
FIG. 13 is a graph comparing the performance of the back cover of the integrating sphere of the present invention with that of a prior art integrating sphere;
FIG. 14 is a comparison of standard particle (4K-02) back-scatter measurements and Mie theoretical calculations;
fig. 15 is a block diagram of the structure of the spectrophotometer-based optical measurement system inherent in phaeocystis globosa capsule according to the embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is to be understood that the embodiments described are merely exemplary embodiments, rather than exemplary embodiments, and that all other embodiments may be devised by those skilled in the art without departing from the scope of the present invention.
In the description of the present invention, it is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising one of 8230; \8230;" 8230; "does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom/front/rear end", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise specifically stated or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like, should be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediate medium, or connected between two elements.
In the description of the present invention, it should be noted that, unless explicitly specified or limited otherwise, the step identifiers S101, S102, S103, etc. are used for convenience only and do not indicate the execution sequence, and the corresponding execution sequence may be adjusted.
Referring to fig. 1, a spectrophotometer-based method for measuring the inherent optical property of phaeocystis globosa capsule comprises:
s101, placing a first cuvette arranged on a fixing frame into an integrating sphere detector of a first spectrophotometer to perform absorption measurement to obtain an absorption coefficient a (lambda); a first spherical phaeocystis coerulea capsule sample is placed in the first cuvette;
s102, when absorption measurement of the phaeocystis globosa capsule body is carried out, an integrating sphere detector of a second spectrophotometer is used for carrying out attenuation measurement to obtain an attenuation coefficient c (lambda); a second cuvette is arranged in a sample bin of the second spectrophotometer, and a second part of spherical phaeocystis globosa capsule sample is placed in the second cuvette;
s103, obtaining a scattering coefficient b (λ), b (λ) = c (λ) -a (λ), based on the absorption coefficient and the attenuation coefficient;
s104, placing the third cuvette in a reflection window of an integrating sphere detector of a third spectrophotometer to perform backscattering measurement, and obtaining a backscattering coefficient b b (λ); a third sample of the spherical phaeocystis fusca capsule is placed in the third cuvette.
It should be noted that, the first, second and third samples of the phaeocystis globosa capsule can be understood as that the same sample is divided into three samples for measurement, and the first, second and third samples of the phaeocystis globosa capsule have the same sample concentration. The absorption measurement in S101 and the attenuation measurement in S102 need to be performed simultaneously, and the backscattering measurement in S103 may be performed simultaneously with or not simultaneously with the absorption measurement in S101 and the attenuation measurement in S102. Correspondingly, the first spectrophotometer and the second spectrophotometer need to perform measurements simultaneously, which means that the measurements are started simultaneously, and a time difference of a certain time, for example, 10 minutes, is allowed for the time of the ending. The third spectrophotometer in S104 may be a spectrophotometer different from those in S101 and S102, or a spectrophotometer in S101 or S102, but the corresponding cuvettes and the corresponding equipment are different from each other, and if the third spectrophotometer shares the spectrophotometer in S101 or S102, it is necessary to perform the measurement in S103 as soon as the measurement in S101 or S102 is completed.
The common method for measuring the absorption coefficient is Quantitative Filter Technology (QFT), although the algorithm is further improved at present, the absorption of particles in a suspension state cannot be reduced, the optical path amplification effect is still a problem which needs to be considered, and the physiological structure of part of phytoplankton (such as phaeocystis globosa with complex life history) is damaged, so that the measurement error is caused. In order to reduce the absorption characteristics of phaeocystis globosa in a suspension state to the maximum extent, the influence of related errors is reduced. In this embodiment, an integrating sphere absorption measurement device equipped with a central cuvette is built based on a spectrophotometer (Lambda 950 or Lambda 850, etc.), so as to complete the relevant absorption measurement of the pure cultured suspension-state phaeocystis fuscus capsule.
Specifically, the absorption coefficient a (λ) is calculated as follows:
wherein l 1 Represents the optical path length of the first cuvette 10; OD s Represents the absorbance value measured by integrating sphere detector 12 of the first spectrophotometer; OD f Represents the absorbance value of the background reference liquid in the first cuvette 10, the background reference liquid being 0.2 μm Nuclecore TM The CDOM solution after filtration through a Polycarbonate or polyester filter.
Referring to fig. 2 and 3, in the present embodiment, the first cuvette 10 is a cylindrical quartz cuvette, the first cuvette 10 is fixed by a fixing frame 11, and during absorption measurement, the fixing frame 11 with the first cuvette 10 fixed thereon is placed in an integrating sphere detector 12 of a first spectrophotometer to perform absorption measurement. Specifically, the first cuvette 10 may be placed in the center of the integrating sphere detector 12 of the first spectrophotometer. Referring to fig. 3, a light source 13 passes through a filter 14, a slit 15, a first cuvette 10 and a reflecting plate 16 in this order, and an integrating sphere detector 12 of a first spectrophotometer detects an absorbance value OD s The measurement is performed. The light source 13, filter 14, slit 15 and reflector 16 of the first spectrophotometer may be existing components of the first spectrophotometer. According to the size of an opening of an integrating sphere detector 12 of a first spectrophotometer, a cylindrical quartz cuvette with the diameter of 2.5cm and the optical path of 4cm is customized, so that an integrating sphere can be just placed in the cylindrical quartz cuvette and a spherical phaeocystis capsule can be accommodated, and the spherical phaeocystis capsule can be better suitable for absorption measurement of the spherical phaeocystis capsule while the structure of the spherical phaeocystis capsule is not damaged. In this embodiment, the integrating sphere detector 12 of the first spectrophotometer has a diameter of 15cm.
Referring to FIG. 4 (a), the monomer strain is measured by QFT in a cuvette integrating sphere system and a conventional method ph The spectra were very consistent, in contrast to the phaeocystis globosa capsules, which caused a significant difference between the two methods. As can be seen from FIG. 4 (b), the coefficient (R) was determined by two methods of measuring the absorption spectrum of the monomer strain 2 ) Up to 0.996, so that the Optical Density (OD) of the single strain suspension can be used to perform path amplification correction on QFT, while the two methods of the capsule strain determine the coefficient (R) 2 ) Only 0.561, which shows that the QFT optical path amplification correction of the capsule strain is not applicable, and this also embodies the present inventionThe capsule body structure of the spherical phaeocystis fuscus is well protected, and errors caused by traditional measurement are avoided.
The attenuation coefficient can be obtained by measuring the light beam transmittance by a spectrophotometer, and since forward scattering of suspended algae cells accounts for a large proportion of the total scattering, in order to reduce the measurement error of the attenuation coefficient c (lambda), the detection distance is increased as much as possible and the slit is reduced in front of the integrating sphere detector to prevent the forward scattering from being detected by the detector. Referring to fig. 5 and 6, in this embodiment, a black slit plate 21 is added in front of the integrating sphere detector 20 of the second spectrophotometer to reduce the forward opening angle to 0.23 °, i.e. the detector can only obtain the transmitted light and the scattered light within 0.23 °, thereby greatly reducing the measurement error and improving the measurement accuracy. In order to ensure the validity of the measurement, the attenuation measurement and the absorption measurement need to be performed synchronously in this embodiment.
Referring to fig. 6, a light source 22 of a second spectrophotometer passes through a filter 23, a slit 24, a sample chamber 25 (a second cuvette, not shown in the figure, is used for attenuation measurement) and a black slit plate 21 in sequence, and an integrating sphere detector 20 of the second spectrophotometer detects an attenuation value OD c The measurement is performed. The light source 22, filter 23, slit 24 and sample compartment 25 of the second spectrophotometer may be existing components of the second spectrophotometer.
Specifically, the attenuation measurement was performed using a two-light-path ultraviolet-visible spectrophotometer (Lambda 850, or the like) with an integrating sphere detector having a diameter of 15cm. Measurement of attenuation (OD) also to reduce the effect of CDOM and culture medium (treatment mode with absorption measurement) on attenuation measurement c ) OD measurement as absorption measurement f The attenuation coefficient c (λ) is calculated as follows:
wherein l 2 Representing the optical path of the second cuvette; OD c Represents the absorbance value measured by integrating sphere detector 20 of the second spectrophotometer; OD f And expressing the absorbance value of the background reference liquid in the second cuvette.
The scattering coefficient b (λ) is calculated as follows:
b(λ)＝c(λ)-a(λ)。
in order to measure the system error of the first spectrophotometer and the second spectrophotometer, two spectrophotometers are used for measuring the absorbance of the same sample, as shown in fig. 7, the determination coefficients of 2 times of measurement results are both above 0.999, and the results show that the measurement results of the two high-performance spectrophotometers have extremely high comparability. There may still be an underestimation of c (λ) due to the problem of the acceptance angle of the detector, but the study error is below 5% when the acceptance angle is less than 0.25 °. To evaluate the reliability of the measurement results, this example was tested using the Duke standards particles of the zemer plane company, and the detailed information of the particles is shown in table (1):
TABLE 1 detailed information parameters of Duke Standard granule 4K-02
The standard particles 4K-02 are mainly composed of Polystyrene (Polystyrene), the central particle size is 2.020 μm, the standard error (SD) ± 0.015 μm, the particle size distribution has the characteristic of Gaussian distribution, and as the Polystyrene has no obvious absorption characteristic, only the real part of the refractive index needs to be considered when the simulation calculation is carried out by utilizing the Mie scattering theory, and the imaginary part is ignored; in addition, the refractive index (C) is changed depending on the wavelength by taking into consideration the particle size distribution of the particleshttps://refractiveindex.info/) And the refractive index of pure water as a particle carrier as a function of wavelength, as shown in fig. 8.
The scattering coefficient of the standard particle 4K-02 measured using the above protocol was compared with that of the Mie-type theoretical simulation, as shown in FIG. 8. Because of the lack of equipment for quantitative measurement of particles in the measurement process, the normalization processing is carried out on the actual measurement result and the theoretical analog value for the convenience of spectrum comparison. From fig. 9 it can be seen that the measured scatter spectrum has a better agreement with the Mie theoretical spectral shape, with only minor differences between 400-440 nm.
For backscatter measurement of the phaeocystis globosa capsule, the third cuvette 30 is placed in the reflective window of the integrating sphere detector of a two-path uv-vis spectrophotometer (e.g., lambda 850) for backscatter flux measurement, as shown in fig. 10-12. First calibrate the instrument using a standard Spectralon reflector plate (>99% reflectance) and then the reflectance (R) of the filtered base solution was measured f ) And then a sample reflectance measurement (R) is performed p ). The backscattering coefficient b b The calculation method of (λ) is as follows:
R p (λ)-R f (λ)＝1-exp(-k×b b (λ)×l 3 )
where k is a quantity related to the measured particle scattering function, set to 1; l 3 Represents the optical path length of the third cuvette 30; r is p (λ) is the reflectance of the third spherical phaeocystis sample; r f (λ) is the measured reflectance of the background reference liquid.
Referring to fig. 10 and 11, in the present embodiment, the third cuvette 30 is a quartz cuvette having a diameter of 2.5cm and an optical length of 10cm; the front end of the third cuvette 30 is provided with a convex hemisphere shape, and the rear end of the third cuvette 30 is provided with black aluminum foil paper; the integrating sphere detector 33 of the third spectrophotometer has a diameter of 15cm. The third cuvette 30 is arranged on a base 31; the end of the integrating sphere detector of the third spectrophotometer is provided with a rear cover 32 covering the base 31, the inner layer of the rear cover 32 is arranged into a honeycomb net structure, and the inner surface is coated with a black coating. In addition, the material of the outer layer of the rear cover can be duralumin or stainless steel, and the material of the inner layer of the rear cover can be aluminum.
Referring to FIG. 12, third spectrophotometryThe light source 34 of the meter passes through the filter 35, the slit 36 and the third cuvette 30 in sequence, and the integrating sphere detector 33 of the third spectrophotometer detects the reflectance R p (lambda) the measurement was carried out. The light source 34, filter 35 and slit 36 of the third spectrophotometer may be existing components of the third spectrophotometer.
Errors in backscatter measurements may result mainly from: (1) instrument error; (2) specular reflection from the front of the quartz cuvette; and (3) specular reflection at the rear end of the quartz cuvette. The performance of the back cover of the integrating sphere customized by the embodiment is better than that of the original back cover of the integrating sphere, the back cover has high absorption and low reflectivity, and the average reflectivity of the new system and the old system in the range of 400-800nm is 0.06% and 0.14%, respectively, as shown in fig. 13. The measurement result of the sample is removed from the measurement result of the 0.2 mu m sample filtrate, and the influence of the mirror reflection at the front end of the quartz cuvette can be counteracted to the maximum extent. The specular reflection at the rear of the cuvette can be reduced by placing an ultra-low reflectance black aluminum foil paper (Thorlabs, inc.) at the rear of the quartz cuvette for the measurement.
To verify the effectiveness of the method, a comparison of the measurement and the theoretical simulation was also performed using standard particles (4K-02). In the Mie theoretical simulation, the backscattering coefficient b is determined b (λ) represents the integral of the scattered flux from π/2 to π, and therefore cannot be used directly
(2002) The Matlab function of (2) was used to estimate the backscattering, where b of the standard particle was estimated using a cubic polynomial fit b (lambda). FIG. 14 shows the results of Mie theoretical simulation and measured spectra, measured over the range of 400-800nm for b b (lambda) Spectroscopy with simulated b b The (lambda) spectrum is well matched.
Referring to fig. 15, the present embodiment is a spectrophotometer-based optical measurement system for the inherent cell body of phaeocystis globosa, including:
an absorption measurement module 1501 for obtaining an absorption coefficient a (λ) by performing an absorption measurement using an integrating sphere detector of a first spectrophotometer; wherein a first sample of spherical phaeocystis fuscus capsules is placed in the first cuvette; a first colorimetric dish arranged on a fixed frame is arranged in an integrating sphere detector of the first spectrophotometer;
an attenuation measurement module 1502 for measuring attenuation by using an integrating sphere detector of a second spectrophotometer to obtain an attenuation coefficient c (lambda) while measuring the absorption of the phaeocystis globosa capsule; wherein, a second cuvette is arranged in a sample bin of the second spectrophotometer, and a second part of spherical phaeocystis fuscoporia capsule sample is arranged in the second cuvette; a black slit plate is arranged between the sample bin of the second spectrophotometer and the integrating sphere detector of the second spectrophotometer;
a volume scattering measurement module 1503 for obtaining a scattering coefficient b (λ) = c (λ) -a (λ) based on the absorption coefficient and the attenuation coefficient;
a backscattering measurement module 1504 for obtaining a backscattering coefficient b by backscattering measurement using the integrating sphere detector of the third spectrophotometer b (λ); wherein, a third cuvette is provided with a third sample of the spherical phaeocystis fuscophyllum capsules; a reflection window of an integrating sphere detector of a third spectrophotometer, in which a base fixed with a third cuvette is placed; and a rear cover for covering the base is arranged at the tail end of the integrating sphere detector of the third spectrophotometer.
The utility model provides a specific optical measurement method of spherical phaeocystis fuliginosus utricule based on spectrophotometer, this embodiment will not repeated the explanation again that concrete realization of each module of spherical phaeocystis fuliginosus utricule inherent optical measurement system based on spectrophotometer is the same.
The foregoing is only a preferred embodiment of the present invention; the scope of the invention is not limited thereto. Any person skilled in the art should be able to cover the technical scope of the present invention by equivalent or modified solutions and modifications within the technical scope of the present invention.
Claims (10)
1. A method for measuring the inherent optical property of the phaeocystis globosa capsule body based on a spectrophotometer is characterized by comprising the following steps:
putting a first cuvette arranged on a fixing frame into an integrating sphere detector of a first spectrophotometer to carry out absorption measurement to obtain an absorption coefficient a (lambda); a first sample of spherical phaeocystis fusca capsules is placed in the first cuvette;
performing attenuation measurement by using an integrating sphere detector of a second spectrophotometer to obtain an attenuation coefficient c (lambda) while performing absorption measurement on the phaeocystis globosa capsule; a second cuvette is arranged in a sample bin of the second spectrophotometer, and a second part of spherical phaeocystis globosa capsule sample is placed in the second cuvette;
obtaining a scattering coefficient b (λ), b (λ) = c (λ) -a (λ), based on the absorption coefficient and the attenuation coefficient;
placing the third cuvette in the reflection window of the integrating sphere detector of the third spectrophotometer for back scattering measurement to obtain the back scattering coefficient b b (lambda); a third sample of the spherical phaeocystis fusca capsule is placed in the third cuvette.
2. The spectrophotometer-based phaeocystis globosa capsule body intrinsic optical measurement method according to claim 1, wherein the absorption coefficient a (λ) is calculated as follows:
wherein l 1 Representing the optical path of the first cuvette; OD s Represents an absorbance value measured by an integrating sphere detector of the first spectrophotometer; OD f And expressing the absorbance value of the background reference liquid in the first cuvette.
3. The spectrophotometer-based method for the inherent optical measurement of the thylakoid body of phaeocystis globosa according to claim 2, wherein the first cuvette is a cylindrical quartz cuvette; the diameter of the first cuvette is 2.5cm, and the optical path is 4cm; the integrating sphere of the first spectrophotometer had a diameter of 15cm.
4. The spectrophotometer-based phaeocystis globosa capsule body intrinsic optical measurement method according to claim 1, wherein the attenuation coefficient c (λ) is calculated as follows:
wherein l 2 Representing the optical path of the second cuvette; OD c Represents the absorbance value measured by the integrating sphere detector of the second spectrophotometer; OD f And expressing the absorbance value of the background reference liquid in the second cuvette.
5. The spectrophotometer-based phaeocystis globosa capsule body intrinsic optical measurement method according to claim 1, wherein a black slit plate is arranged between the sample chamber of the second spectrophotometer and the integrating sphere detector of the second spectrophotometer, and the forward opening angle of the black slit plate is not more than 0.23 ° so that only transmitted light and scattered light within the forward opening angle can be obtained by the detector; the integrating sphere of the second spectrophotometer had a diameter of 15cm.
6. The spectrophotometer-based phaeocystis globosa capsule body intrinsic optical measurement method according to claim 1, wherein the backscattering coefficient b is b The calculation method of (λ) is as follows:
R p (λ)-R f (λ)＝1-exp(-k×b b (λ)×l 3 )
wherein k is set to 1; l. the 3 Representing the optical path of the third cuvette; r p (lambda) is the reflectance of the third spherical phaeocystis cell body sample; r f (λ) is the measured reflectance of the background reference liquid.
7. The spectrophotometer-based method for the inherent optical measurement of the thylakoid body of phaeocystis globosa according to claim 6, wherein the third cuvette is a quartz cuvette; the diameter of the third cuvette is 2.5cm, and the optical path is 10cm; the front end of the third cuvette is provided with a convex hemisphere, and the rear end of the third cuvette is provided with black aluminum foil paper; the integrating sphere of the third spectrophotometer had a diameter of 15cm.
8. The spectrophotometer-based phaeocystis globosa capsule body intrinsic optical measurement method according to claim 7, wherein the third cuvette is disposed on a base; the end of an integrating sphere detector of the third spectrophotometer is provided with a rear cover covering the base, the inner layer of the rear cover is of a honeycomb net structure, and the inner surface of the rear cover is coated with a black coating.
9. The spectrophotometer-based method for inherent optical measurement of phaeocystis globosa capsules according to claim 2, 4 or 6, wherein the background reference liquid is 0.2 μm Nuclepore TM The CDOM solution after filtration through a Polycarbonate or polyester filter.
10. A spectrophotometer-based optical measurement system inherent to the capsule body of phaeocystis globosa, comprising:
an absorption measurement module for obtaining an absorption coefficient a (lambda) by performing absorption measurement using an integrating sphere detector of the first spectrophotometer; wherein a first sample of spherical phaeocystis fusca capsules is placed in the first cuvette; a first colorimetric dish arranged on a fixed frame is arranged in an integrating sphere detector of the first spectrophotometer;
the attenuation measurement module is used for carrying out attenuation measurement by using an integrating sphere detector of a second spectrophotometer to obtain an attenuation coefficient c (lambda) while carrying out absorption measurement on the phaeocystis globosa capsule body; wherein, a second cuvette is arranged in a sample bin of the second spectrophotometer, and a second part of spherical phaeocystis fuscoporia capsule sample is arranged in the second cuvette; a black slit plate is arranged between the sample bin of the second spectrophotometer and the integrating sphere detector of the second spectrophotometer;
a volume scattering measurement module for obtaining a scattering coefficient b (λ) = c (λ) -a (λ) based on the absorption coefficient and the attenuation coefficient;
a backscattering measurement module for obtaining backscattering coefficient b by backscattering measurement using an integrating sphere detector of a third spectrophotometer b (lambda); wherein, a third cuvette is provided with a third sample of the spherical phaeocystis fuscophyllum capsules; a reflection window of an integrating sphere detector of a third spectrophotometer on which a base fixed with a third cuvette is placed; and a rear cover for covering the base is arranged at the tail end of the integrating sphere detector of the third spectrophotometer.
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