Mixed micelles assisted room-temperature cloud point extraction for preconcentration and spectrophotometric...

A novel mixed micelles room-temperature cloud point extraction (MM-RT-CPE) for preconcentration of Molybdenum(VI) coupled with spectrophotometric detection was proposed. The developed method includes the formation of red complex of Molybdenum(VI) with 6,7-dihydroxy-2-phenyl-4-carboxylbenzopyrylium perchlorate and cationic surfactant cetylpyridinium bromide, its extraction at room temperature into chemically induced mixed micelles surfactant rich phase and absorbance measurement at 555 nm. Optimal MM-RT-CPE conditions were found to be: 1.5 % (v/v) of Triton X-100, 3.5·10^-4 mol L^-1 of cetylpyridinium bromide and 0.04 mol L^-1 of sodium salicylate for initiating of MM-RT-CPE; pH 1.0; 2.5·10^-5 mol L^-1 of chelating reagent. The calibration plot is linear in the Molybdenum(VI) concentrations range of 5-350 μg L^-1 and the limit of detection is 1.5 μg L^-1. The enrichment factor and the preconcentration factor were 11.5 and 33 respectively. The developed MM-RT-CPE procedure has been successfully applied to UV-Vis spectrophotometric determination of Molybdenum(VI) traces in water and pea samples. The environmental friendliness of the proposed method was confirmed using several modern assessment tools.