OPTICAL CHEMOSENSOR BASED ON METHYLDIMERCAPTOTHIOPYRON FOR SPECTROPHOTOMETRIC DETERMINATION OF PALLADIUM(II)

An optical chemical sensor for the determination of palladium(II) by spectrophotometry is proposed, which is manufactured by immobilizing 3-methyl-2,6-dimercapto-1,4-thiopyrone (MDT) in a polyvinyl chloride matrix. The influence of various parameters was studied, the conditions for spectrophotometric detection of Pd(II) were optimized, and methods for its determination were developed using a calibration graph method, for which the linearity range (mu g L-1) was set: 0.02-1.60, detection limits 0.016 mu g mL(-1) in a sample volume of 20 mL. The developed highly selective methods are based on the formation of a colored Pd(II) complex compound in the indicator polyvinyl chloride matrix of a sensitive element with an absorption maximum of 465 nm. The accuracy of the developed method was assessed by analyzing a certified reference material (platinum-palladium alloy), the relative standard deviation was 2.4 %. The proposed optical chemosensor can be used for quantitative and qualitative measurement of Pd(II) ions in various real samples without any significant interference from a significant excess of various ions, including chalcophilic metals, and including a number of noble metals, easily regenerated and offered for multiple use. The developed method was tested in the analysis of drinking water, water of the Dnipro river and was successfully applied to determine Pd in the sewage sludge of a palladium electroplating bath, the relative standard deviation did not exceed 3 %.