T. Perez-ruiz et al., Flow-injection spectrofluorimetric determination of dissolved inorganic and organic phosphorus in waters using on-line photo-oxidation, ANALYT CHIM, 442(1), 2001, pp. 147-153
The development and application of a continuous flow method for the rapid d
etermination of inorganic and organic phosphorus in waters is proposed. The
flow-injection (FI) system includes a simple ultraviolet photoreactor for
the on-line photodegradation of organophosphorus compounds in the presence
of peroxydisulphate, and an external decomposition unit for hydrolysing con
densed phosphates with 0.5 mol l(-1) hydrochloric acid. The fluorimetricall
y monitored product is thiochrome, which is formed by the oxidation of thia
mine by phosphomolybdic acid. The FI configuration designed allows two inje
ctions to be performed for each sample; the first, without irradiation, cor
responds to inorganic phosphorus and the second, with irradiation, total ph
osphorus (inorganic plus organic).
Calibration graphs are linear up to 350 ng P ml(-1) and the detection limit
is 0.3 ng P ml(-1). The results obtained with this FI system were in good
agreement with those obtained by a batch spectrophotometric method [1]. (C)
2001 Elsevier Science B.V. All rights reserved.