Determination of Inorganic Arsenic Species in Drinking Water by Cloud Point Extraction Coupled with Ultraviolet-Visible Spectrophotometry

Abstract

A novel method has been developed for accurately quantifying arsenic species, including As(III), As(V), and total inorganic arsenic, in drinking water. The technique combines ultraviolet-visible spectrophotometry with cloud point extraction (UV/CPE), ensuring high sensitivity and selectivity. The methodology relies on complex formation between As(III) and Pyronin B in the presence of tartaric acid. The resulting complex is efficiently extracted into the surfactant-rich phase consisting of 5.0% (v/v) Triton X-114. Under optimized conditions, a linear calibration relationship from 3 to 500 µg/L is obtained. The method offers low detection and quantification limits of 1.04 and 3.48 µg/L, respectively, with a corresponding relative standard deviation below 5% for 11 replicates. Furthermore, spiked samples demonstrated excellent recovery values from 95.1% to 102.3%. The accuracy was verified by the analysis of the standard reference material SRM 1643e (trace elements in water), revealing no significant differences at the 95% confidence level. The approach was successfully utilized for the quantification of As(III), As(V), and total inorganic arsenic in commercial and domestic drinking water.

Keywords:

• Arsenic speciation
• cloud point extraction
• drinking water analysis
• pyronin B
• ultraviolet-visible spectrophotometry

Disclosure statement

All authors report no relevant relationships.

Additional information

Funding

This work was partially supported by the Science and Technology Research Program of Chongqing Municipal Education Commission of China (Grant Nos. KJQN202201438 and KJQN202301418).