Salt Error in Determinations of Phosphate in Sea Water

Publisher Website
Google Scholar
Abstract
The yellowing which may occur during phosphate determinations in sea water is attributed to hydrolytic products of complex molybdenum halides.When 1 ml. of the usual acid molybdate reagent is used per 100 ml. of water, addition of copper as recommended by Kalle reduces the development of colour in sea water samples and in distilled water standards to the same extent. The correction factor 1·12 applies to comparison by daylight in Hehner cylinders and to photometric determinations with a red filter.When 2 ml. of reagent is used per 100 ml. of water, the factor depends on the method of comparison. With comparison by daylight in Hehner cylinders it is 1·35, whereas if a photometer with a red filter is used it is only 1·19.