Solvent extraction and trace analysis of as (III) in alloys, biological, and environmental samples by spectrophotometry and ICP-MS

A novel method for the simple and selective separation and trace detection of arsenic is described. Arsenic is efficiently extracted at pH 5.5 using 7-hydroxy-4-methylcoumarin hydroxyl amine (HMCHA) in dichloromethane, showing maximum absorbance at 395 nm with a molar absorptivity (ε) of 1.21 × 104 L mol⁻1 cm⁻1. The method follows Beer's law for concentrations between 0.99 and 8.916 µg L⁻1. Sensitivity is enhanced 60-fold by directly injecting the extract into the plasma for ICP-MS analysis, allowing accurate estimation of trivalent arsenic. The extraction is unaffected by the presence of other ions, with no interference observed. The method's effectiveness is confirmed through the analysis of arsenic in alloys, water, biological, and environmental samples.