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Chlorophyll a Determination: Improvements in Methodology

Osmund Holm-Hansen and Bo Riemann
Oikos
Vol. 30, No. 3 (1978), pp. 438-447
Published by: Wiley on behalf of Nordic Society Oikos
DOI: 10.2307/3543338
Stable URL: http://www.jstor.org/stable/3543338
Page Count: 10
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Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Chlorophyll a Determination: Improvements in Methodology
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Abstract

Chlorophyll and phaeopigment determinations on fresh water and marine samples of phytoplankton have shown that the following considerations are important in routine pigment analyses. (a) Methanol should be used as extraction solvent instead of acetone due to better extraction efficiency, shorter extraction time, and elimination of the need to boil or homogenize the samples. (b) For spectrophotometric determinations of phaeopigments, the methanol extracts should be acidified with HCl to a final concentration of 3× 10-3 M. (c) When a spectrophotometer is used for phaeopigment determination, subsequent neutralization of the acidified methanol extracts to the original pH is required; fluorometric determinations do not require this neutralization. (d) The addition of MgCO3 to filters or to extracts is not necessary. (e) There is no detectable loss of chlorophyll when either sample extracts or wet filters are stored at -20°C for three weeks and then extracted with either acetone or methanol. (f) Glass fiber filters are effective in retaining all phytoplankton and have some advantages over membrane filters. /// Определения содержания хлорофилла и феопигмента в пробах пресноводного и морского фитопланктона показали, что в системе анализа пигмента имеют значение следующие соображения: а/ для экстракции следует исполъзоватъ вместо ацетона метанол, обладающий более высокой эффективностъю экстракции, более короткой продолжителъностъю экстракции, не требующей кипячения или гомогенизации проб; б/ для спектрофотометрических определений феопигментов метаноловые экстракты долкны бытъ подкислены соляной кислотой до окончателъной концентрации 3× 10-3 м; в/ при исполъэовании спектрофотометра для определения феофермента необходима последователъная нейтрализация подкисленных метаноловых экстрактов до исходной рн. фл\r=,?\орометрические определения не требу\r=,?\т нейтрализации; г/ добавление MgCO3 к филътру или экстракту не требуется; д/ при хранении экстрактов проб или влажных филътров при -20° в течение 3-х неделъ с последу\r=,?\щей экстракцией ацетоном или метанолом заметных потеръ хлорофиллане установлено; е/ филътры из стеклянного волокна эффективно удержива\r=,?\т весъ фитопланктон и име\r=,?\т преимущество перед мембранными филътрами.

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