1. Applying and comparing two chemometric methods in absorption spectral analysis of photopigments from Arctic microalgae
- Author
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Zhang, Fang, He, Jianfeng, Xia, Lihua, Cai, Minghong, Lin, Ling, and Guang, Yingzhi
- Subjects
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CHEMOMETRICS , *ABSORPTION spectra , *MICROALGAE , *CAROTENOIDS , *CHLOROPHYLL , *CHLORELLA , *WAVELETS (Mathematics) , *PIGMENTS , *CAROTENES - Abstract
Abstract: Pigment absorption property of two arctic microalgae species (Skeletonema marinoi and Chlorella sp.) cultured at three temperatures (0, 4 and 8°C) was analyzed. Carotenoids and chlorophyll (Chl) c were positive factors to the high cell activities and primary productivities of S. marinoi at 4°C and 0°C, respectively; whereas Chl a had a positive effect on Chlorella sp. at all three temperatures, and carotenoids had a relatively high effect at 0°C. The absorption locations of photopigments were analyzed in detail using both fourth derivative and Symlet-6 wavelet analysis. Both methods precisely detected pigments with a relative large content; the fourth derivative analysis specifically detected the existence of a Chl a peak at about 410nm and showed better differentiation of diatoxanthin, whereas the wavelet analysis distinctively indicated the existence of chlorophyllide a, β-carotene, and Chl c. The separation limit to pigment peaks of the fourth derivative spectra (4nm) was 1nm higher than that of the wavelet high-frequency spectra (3nm). The wavelet high-frequency spectra were more stable in detecting pigment locations and were more effective in discriminating microalgae. Small algebraic difference of 10−16 between the reconstructed absorption spectra obtained by the inverse wavelet transform and their corresponding original spectra also showed the validity of Symlet-6 wavelet in the detection of pigments. Another specific discovery of this research is the existence of a Chl a allomer in Chlorella sp., which was detected by both methods. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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