Spectrophotometric determination of dissolved organic phosphorus in natural waters using in-line photo-oxidation and flow injection

Abstract

A rapid in-line photochemical digestion for use with flow injection (FI) to determine the dissolved organic phosphorus (DOP) in natural waters is described. The FI system includes a simple ultraviolet (UV) photoreactor and uses the tin(II) chloride reduction of phosphomolybdate for the spectrophotometric determination of the dissolved reactive phosphorus (DRP) produced by the photo-oxidation. Samples in the range 0.1-4 and <0.1 mg I-1 of P can be analysed at rates of 72 and 50 samples h -1, respectively. The effective detection limit of the technique was 0.01 mgI-1. Comparison of the results for DOP obtained using the proposed method were in good agreement with those obtained using standard ..