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Problems in filtration fractionation of 14C primary productivity samples
Author(s) -
Lignell Risto
Publication year - 1992
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1992.37.1.0172
Subject(s) - filtration (mathematics) , fractionation , primary productivity , chemistry , productivity , cellulose , chromatography , primary (astronomy) , cellulose acetate , environmental chemistry , environmental science , organic chemistry , mathematics , nutrient , statistics , physics , astronomy , economics , macroeconomics
Sources of error in the fractionation of 14 C primary productivity samples were studied in the northern Baltic from 1984 to 1990. Acidification of the whole 14 C sample followed by 24 h in open vials to remove 14 CO 2 (no bubbling) proved to be a simple, accurate, and precise (C.V. 6.9%, n = 128) method for measuring apparent net primary productivity (total organic 14 C). In 1985, the total recovery of organic 14 C with 0.2‐ µ m cellulose acetate filters was 81% of the annual apparent net primary production. Different post‐filtration treatments of the cellulose ester filters (rinsing, acidification) all gave significant unaccountable losses of up to 34% of organic 14 C. No losses were recorded with glass‐fiber filters. Excess release of dissolved organic 14 C due to filtration was generally unimportant, as only minor quantitative or qualitative differences were found between the <0.2‐ µ m filtrates of the whole and centrifuged samples.