Visible pigment concentration measurement

Pigments from cells or thylakoid membranes were extracted in 80 % acetone and debris was removed by centrifugation at 10,000 g for 5 min. The absorbance of the supernatant at 652 nm was measured by a Shimadzu UV-visible spectrophotometer. The chlorophyll (a and b) concentration of the samples was determined according to Amon [1949], with equations corrected as in Melis et al. [2000],... 

Spectroscopic methods for measuring the absorbance of pigment solutions or the adsorbance of the color of product surfaces on one or more wavelengths in the visible range are excellent tools for the accurate determination of the quantity of pigments however, they do not contain any useful information on the concentration of the individual pigment fractions. 

Because of the fairly high extinction coefficient (3.36538 x 10 ), very small amounts of copper phthalocyanine blue pigments can be detected and measured. Figure 21-1 shows the visible spectrum of Copper Phthalocyanine Blue at a concentration of 62 p.g/L in 1-methyl-naphthalene (Imax 677nm). 

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