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Advisor(s)
Abstract(s)
The spectrophotometric determination of nitrate in sea water broths for cultivation of, say, microalgae is complicated
by the frequent presence of nitrite. Two methods - sulphamic/perchloric acid method (also known as Cawse method) and sulphamic
acid method - both claimed to be able to eliminate nitrite interference, were tested using a set of standards, but statistical
treatment of the results proved their limitations in nitrate quantification. An improved method, based on former published
methods for quantification of nitrite and coupled determination of nitrate and nitrite, was designed and tested. This improved
method was compared with the reference method (based on use of a cadmium column) using several standards and biological
samples of two culture media for microalgae, in different phases of their growth curve. The results thus obtained have demonstrated
that there is no statistically significant difference between them at the 5% level. The precision of the method was tested
by repeating determinations with three sets of standard mixtures containing nitrate and nitrite. The method proposed has advantages
over conventional methods in reduced time of analysis, as well as high precision and accuracy, so it may be a good alternative
for determination of nitrite and nitrate in marine aqueous media.
Description
Keywords
Enriched sea water microalgae broth Nitrate quantification Nitrite quantification Spectrophotometry
Citation
CARVALHO, A. P.; MEIRELES, L. A.; MALCATA, F.X. - Rapid spectrophotometric determination of nitrates and nitrites in marine aqueous culture media. Analusis. ISSN 0365-4877. Vol. 26 (1998), p. 347-351
Publisher
EDP Sciences, Wiley-VCH