Determination of manganese at trace levels in water by laser-enhanced ionization spectrometry after solvent extraction

Abstract

Solvent extraction was combined with one-step laser-enhanced ionization (LEI) spectrometry for the determination of trace amounts of manganese in water. The LEI signal was measured at 279.5 nm. Experimental conditions such as laser power, cathode potential, distance between cathode and burner head and laser beam height were optimized for the diisobutyl ketone extract of the manganese chelate with sodium diethyldithiocarbamate. With the solvent extraction method, the interferences from easily ionizable elements such as Na, K, Ca and Mg were completely eliminated and the detection limit (signal to noise ratio = 3) was improved to 0.09 ng ml^–1 with a 10-fold concentration. The method was successfully applied to the analysis of ground, river, lake, sea, tap and waste waters.