|
Dimensional fluorescence spectrometry with high sensitivity, and can give the whole excitation and emission wavelength range of the fluorescent fingerprint information can be achieved is a direct, rapid phytoplankton species and analytical methods. This paper aims to extract spectral features, combined with a variety of chemometric methods to establish a fast classification method based on the fluorescence characteristics of marine phytoplankton, the classification between biomorphic classification categories (Division) and the case (Genus). Selected 25 kinds belonging to the species or the dominant species of phytoplankton in the five categories of red tide laboratory culture, including seven kinds of dinoflagellates: Alexandrium algae (Alexandrium, is tamarense) donghaiense dinoflagellate (Prorocentrum micans) marine Prorocentrum ( Prococentrum marinum), Gymnodinium (Gymnodinium sp.), Jane Gymnodinium Gymnodinium simplex, micro-Prorocentrum (Prorocentrum minimum), Scrippsiella trochoidea (Scrippsiella trochoidea); 10 diatoms: Spiked intends rhombus algae (Pseudo-nitzschia pungens (PS0201-01)), Skeletonema costatum (of Skeletonema costatuma), round screen algae (Coscinodiscus sp.), fine column, algae (Cylindrotheca closterium), Biddulphia (Odontella cf_sinensis), spin chain angle hair algae (Chaetoceros Curvisetus), the gracilis (Chaetoceros Debilis), double sudden Chaetoceros (Chaetoceros Didymus), round sea the chain the algae (Thalassiosi rarotula), Brinell the double the the Sargassum (Ditylum brightwellii); 2 kinds of algae: Chlorella (Chlorella pynenoidosa), island large flat algae (Platymonas helgolanidica); 2 cyanobacteria: Synechococcus (Synechocoocus sp.), Anabaena (Cyanophyceae Anabaena sp.); coloring dinoflagellates: Phaeocystis ( Phaeocystis globosa), implicit algae (Rhodomonas sp.), the brine cryptalgal (Rhodomonas salina is), the oceans card shield the algae (Chattonella marina) under different experimental conditions, including the three temperature levels (25 ° C, 20 ° C, 15 ° C) 5 light levels (15000 lux, 10000 lux, 7000 lux, 4100 lux, 1180 lux), three-dimensional fluorescence spectroscopy of marine phytoplankton. Major studies include: 1. Study based on fluorescence characteristics of marine phytoplankton spectrum category. First remove the Rayleigh scattering of the original three-dimensional fluorescence spectroscopy, principal component analysis (PCA) to extract the characteristic spectrum. Spectral similarity to the average similarity coefficient R and the first principal component contribution rate S1 / two metrics examine characteristics. The results show that the two similarity metrics trend is substantially the same as S1 / trend is relatively obvious. 30 representatives spectral classification and discrimination on phytoplankton, the first based on the similarity measure and cluster analysis of each algal extract one or more spectra represent the original characteristic spectrum, a total of 25 kinds of algae. Combined ratio method and system clustering method based on principal component analysis of the characteristics of projection display, divided into 25 kinds of algae 10 \between \2 standard chlorophyll a (Chl a) investigated the basis of the detection limit of the method. First, the observed standard Chl a three-dimensional and fluorescence excitation spectra the paper selected emission wavelength of 665 nm, the excitation wavelength 380,410,430 nm three mean fluorescence intensity as the value of the fluorescence intensity of the corresponding concentration of Chl a, Chl a standard curve . On IUPAC method calculation method detection limit for 0.065μg / L; qualitative detection limit is 1.85μg / L, quantitative detection limit is 2.77μg / L ISO new estimation method. Then, the limit of detection of the effects of living under the conditions of the experimental apparatus phytoplankton fluorescence spectrometry. From the three-dimensional fluorescence spectra, emission wavelength 670-680 nm, the excitation wavelength of 440 nm at the mean of the fluorescence intensity, and the fluorescence intensity of the selected standard of Chl a corresponding standard Chl a concentration expressed phytoplankton abundance. Vivo phytoplankton detection limit according to IUPAC as 0.10μg / L; to each algal experimental actual detection limit in the 2.5-20.0μg / L. 3. Phytoplankton in the in vivo analysis of the fluorescence spectra identification method. Nonnegative least squares (NNLS) traversal of experimental design 660 single samples and 105 mixed samples were analyzed and discussed the provisions of the determination of the number of species split the correct rate, selected split coefficient threshold value of 0.2 . \The remaining 95 mixed samples the qualitative correct rate can reach 95%. In summary, 25 algae-based spectral data, divided into 10 spectral class \
|