Solid-phase Spectrophotometric Determination of Mo(VI) using Organopolymeric Cation Exchange Resin KU-2-8 Modified by 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium chloride

The current work is devoted to the study of a sorbent based on organopolymeric cation exchange resin KU-2-8 modified with 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium chloride for preconcentration and solidphase spectrophotometric determination of Mo(VI) microquantities. The optimal conditions for the preconcentration of Mo(VI) by the proposed sorbent were found to be: pH 5.5, a portion of the sorbent 0.5 g with a grain diameter of 0.43 ÷ 0.50 mm with shaking for 60 min (for static mode) or at a rate of 2 cm3/min with using a column with a 10 mm diameter (for dynamic mode). The calibration graph for solid-phase spectrophotometric determination of Mo(VI) after its sorption preconcentration using the modified sorbent in static mode is linear in the concentration range of 0.15-4.24 mg/dm3, and the values of the limit of detection and limit of determination are 0.05 and 0.15 mg/dm3 respectively. The proposed method was tested in the analysis of a sample of peas with a relative standard deviation no more than 4.9 %.