Contribution
Spectrofluorometric determination of chlorophylls and pheophytins
Neveux, Jacques; Panouse, Michel
Archiv für Hydrobiologie Volume 109 Number 4 (1987), p. 567 - 581
30 références bibliographiques
publié: Jul 6, 1987
DOI: 10.1127/archiv-hydrobiol/109/1987/567
ArtNo. ESP141010904005, Prix: 29.00 €
Abstract
The use of selective fluorescence excitation and emission wavelengths in the determination of chlorophylls and pheophytins in crude acetone extracts of marine phytoplankton is tested. The method does not include acidification. Using the less expensive types of spectrophotofluorometer (non-corrected), it is necessary to have a convenient stable reference to check the instrument and to correct fluorescence measurements. BOTO & BUNT (1978) used quinine sulfate solutions as reference. However, it appears more convenient to take a reference showing excitation and emission spectra in the same wavelength range as that of chlorophyll pigments. Pheophytin-a in polymethylmethacrylate represents such a reference. Accuracy in a pigment determination is dependent on its quantum yield, its relative abundance and its spectral overlap with those of other pigments present. For marine samples, better assessment for chlorophylls-a, -b and -c can be expected using spectrofluorometry than by more traditional methods. Good accuracy for pheophytin-a is also found when it represents at least 10% of the total chlorophyll-a + pheophytin-a. Weak or no accuracy in pheophytin-b and pheoporphyrin-c concentrations is observed.
Mots-clefs
wavelengths • chlorophylls • pheophytins • phytoplankton • spectrophotofluorometer