The use of oxidation reactor for water sample preparation in the total phosphate determination using Segmented Flow Analysis

Abstract

The pollution in surface waters such as rivers, lakes/reservoirs and estuarine is mostly caused by domestic waste; one of them is detergent. Detergents used in households contain phosphate that disrupts the ecosystem. In the determination of detergents, sample preparation is one of the most important stages. This study describes the use of an oxidation reactor with UV radiation for the destruction of total phosphate compounds in detergent into dissolved phosphates in the preparation stage of detergent determination. With this method, the destruction of total phosphate in detergent samples required a very short time and could be connected directly to the Segmented Flow Analysis device. In this study, the oxidation reactor was tested on artificial samples containing 0.5% detergent and water samples from the Citarum and Cikapundung Rivers (Bandung, Indonesia) which were estimated to be contaminated with detergent. The average concentrations of total phosphate of the samples from Cikapundung and Citarum were 4.5773 ± 0.2286 mg-PO43-/l and 4.1841 ± 0.0361 mg-PO43-/l, respectively. Meanwhile, the average concentration of total phosphate of the artificial sample was 5.5727 ± 0.1830 mg-PO43-/l. The results show that the sample digestion method using UV radiation in the oxidation reactor can provide excellent results with a high recovery at 94.51%.