Errors in Molybdenum Blue Methods for Determining Orthophosphate in Freshwater
- 1 March 1980
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Fisheries and Aquatic Sciences
- Vol. 37 (3) , 472-478
- https://doi.org/10.1139/f80-061
Abstract
Whole lakewater was spiked with carrier free 32PO4, filtered through a 0.45-μm membrane filter and the filtrate fractionated using G-25 Sephadex. Three molecular weight fractions incorcorporated 32P labeling, one of which was colloidal. This labeled filtrate was treated with several variations of the molybdenum blue method for measuring orthophosphate followed by molecular weight fractionation. All variations in the molybdenum blue method caused a significant loss of phosphorus from the colloidal fraction. Phosphorus originating from the colloidal fraction tested as orthophosphate giving an overestimate of the true orthophosphate present.Key words: orthophosphate, analytical errors, freshwaterThis publication has 7 references indexed in Scilit:
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