Pre-concentration system for bismuth determination in urine using FI-ICP-AES with ultrasonic nebulization

A bismuth pre-concentration and determination system implemented with inductively coupled plasma atomic emission spectrometry( ICP-AES) associated with a flow-injection (FI) method with an ultrasonic nebulizalion system was studied. For the retention and on-line pre-concentration of bismuth, quinolin-8-ol and Amberlite XAD-7 were used at pH 5.0. The bismuth complex was removed from the micro-column with nitric acid. The detection limit for the pre-concentration of 100 ml of aqueous solution was 0.03 ng ml(-1) with a relative standard deviation (RSD), of 2.5%, calculated with the peak heights obtained. The RSD for the human urine samples were between 1 and 5%. This reflects the cumulative imprecision of all the process. The calibration graph using the preconcentration system for bismuth was linear with a correlation coefficient of 0.9991 at levels near the detection limits up to at least 100 ng ml(-1). The method was succesfully applied to the determination of bismuth in human urine samples digested previously with a mixture of H2O2 and HNO3.