We have measured the relationship between chlorophyll and carbon in phytoplankton cultures and natural populations of phytoplankton using simple standard extraction procedures without correction for degradation products. During exponential growth oi four cultures oi unicellular and colonial green algae and one diatom, chlorophy!l varied from 1.22 to 6.08% of the phytoplankton carbon content (i ...

A three-way resolution method based on PARAFAC analysis of fluorescence excitation/emission matrices (EEMs) is presented to study the black kinetic system of simultaneous degradations of chlorophyll a and b extracted with other interferents from fresh spinach. The excitation and emission spectral profiles as well as the kinetic concentration profiles of chlorophyll a, b and their degradation pr...

The ambient mass spectrometry technique, desorption electrospray ionization mass spectrometry (DESI-MS), is applied for the rapid identification and spatially resolved relative quantification of chlorophyll degradation products in complex senescent plant tissue matrixes. Polyfunctionalized nonfluorescent chlorophyll catabolites (NCCs), the "final" products of the chlorophyll degradation pathway...

The yellowing of paper on aging causes major aesthetic damages of cultural heritage. It is due to cellulose oxidation, a complex process with many possible products still to be clarified. By comparing ultraviolet-visible reflectance spectra of ancient and artificially aged modern papers with ab initio time-dependent density functional theory calculations, we identify and estimate the abundance ...

Chlorophyll synthesis and degradation were analyzed in the cyanobacterium Synechocystis sp. PCC 6803 by incubating cells in the presence of 13C-labeled glucose or 15N-containing salts. Upon mass spectral analysis of chlorophyll isolated from cells grown in the presence of 13C-glucose for different time periods, four chlorophyll pools were detected that differed markedly in the amount of 13C inc...