Clorofila

Standard procedure for the determination of chlorophyll a by spectroscopic methods

Alain Aminot IFREMER Centre de Brest BP 70 F-29280 Plouzané France and Francisco Rey Institute of Marine Research P.O. Box 1870 Nordnes N-5817 Bergen Norway

International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer
Palægade 2–4 DK-1261 Copenhagen K DenmarkMarch 2000 ISSN 0903-2606

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TABLE OF CONTENTS
Section 1 2 Page

INTRODUCTION............................................................................................................... 1 CONTEXT AND DIFFICULTIES OF CHLOROPHYLL a DETERMINATION............ 1 2.1 2.2 2.3 2.4 Interfering Chlorophylls and Degradation Products ................................................. 1 Occurrence and Significance of the Chlorophyll Group Pigments ........................... 2 Spectroscopic Characteristics and Resulting Measurement Methods....................... 2 2.3.1Spectrophotometry.......................................................................................... 2 2.3.2 Fluorometry .................................................................................................... 3 Critical View of the Preparation of Pigment Extracts............................................... 3 2.4.1 Sampling and sub-sampling............................................................................ 3 2.4.2 Filtration......................................................................................................... 3 2.4.3 Storage of the filters........................................................................................ 4 2.4.4 Extraction of the filters ................................................................................... 5 SpectroscopicMeasurements.................................................................................... 6 2.5.1 Choice of the method...................................................................................... 6 2.5.2 Spectrophotometry.......................................................................................... 7 2.5.3 Fluorometric measurement ............................................................................. 82.5

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PROCEDURE ................................................................................................................... 8 3.1 3.2 3.3 3.4 3.5 3.6 Sampling ................................................................................................................... 8 Filtration................................................................................................................... 9 Storage Of The Filters............................................................................................... 9 Pigment Extraction.................................................................................................. 10 Centrifugation ......................................................................................................... 10Spectroscopic Measurement ................................................................................... 11 3.6.1 Spectrophotometry: trichromatic method ..................................................... 11 3.6.2 Spectrophotometry: monochromatic method with acidification................... 11 3.6.3 Fluorometry.................................................................................................. 12

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SUMMARY OF OPERATIONAL CONDITIONS.......................................................... 14 QUALITY CONTROL ..................................................................................................... 14 ALTERNATIVE PROCEDURES .................................................................................... 15 ACKNOWLEDGEMENT...