A novel on-line preconcentration method for trace molybdenum determination by USN-ICP OES with biosorption on immobilized yeasts

Abstract

A new system for on-line preconcentration of molybdenum by sorption on a minicolumn associated to inductively coupled plasma - optical emission spectrometry with ultrasonic nebulization was studied. It is based on the sorption of molybdenum on a column packed with immobilized baker's yeasts on controlled pore glass without further complexing reagent. The molybdenum preconcentrated by biosorption was subsequently eluted with hydrochloric acid. Considering a sample flow rate of 5.0 mL min- 1, 10 mL of sample was preconcentrated in 2 min achieving a sensitive total enhancement factor of 480-fold, and the detection limit (3 s) obtained was 21 ng L- 1. Additionally, the calculated precisions expressed as percent relative standard deviation (RSD%) was 1.9%. Satisfactory results were obtained for the determination of molybdenum in standard reference material NIST 1643e Trace Elements in Water and real water samples.