A method for the measurement of particulate C and P on the same filtered sample

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 217:59-65 (2001) - doi:10.3354/meps217059 A method for the measurement of particulate C and P on the same filtered sample G. G. Lampman, N. F. Caraco*, J. J. Cole Institute of Ecosystem Studies, Box AB, Millbrook, New York 12545, USA *Corresponding author. E-mail: caracon@ecostudies.org ABSTRACT: There is substantial interest in measuring C:P ratios in aquatic systems because these particulate ratios may influence food quality of phytoplankton to zooplankton grazers. In most analyses C is measured by dry combustion using a CN analyzer requiring that P be measured on a separate sample. We show for marine and freshwater phytoplankton cultures and naturally occurring seston that C can be measured by a variation of the same wet-persulfate digestion method frequently used for P analysis, allowing C and P to be measured on the same filter. Over a large range of C values (1 to 40 µmol C filter-1), the persulfate method for measuring C gave the same C value for lake seston, estuarine seston, and marine and freshwater phytoplankton cultures as high temperature dry combustion on a Carlo-Erba CN analyzer. For C, the wet digestion method is much less expensive than the dry combustion method in terms of both equipment and per-sample materials costs. Further, the persulfate method is more precise (CV = 3%) than the dry combustion method (CV = 12%) for the measurement of C. This greater precision of C measurement, and the fact that C and P are measured on the same sample, means that small differences in C:P ratios can more readily be detected. KEY WORDS: Particulate · Phosphorus · Carbon · Method · C:P ratio Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 217. Online publication date: July 31, 2001 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2001 Inter-Research.