On-line preconcentration system for lanthanum determination in urine using FI–ICP-AES Original Research Article

An on-line lanthanum preconcentration and determination system implemented with inductively coupled plasma-atomic emission spectrometry (ICP-AES) associated to flow injection (FI) method was studied. For the retention of lanthanum, quinolin-8-ol and Amberlite XAD-7 were used at pH 9.5. The lanthanum complex was removed from the micro-column with nitric acid. The value of detection limit for the preconcentration of 100 ml of aqueous solution was 0.09 ng ml−1 with a relative standard deviation (RSD) of 1.5%, calculated with the peak heights obtained. The calibration graph using the preconcentration system for lanthanum was linear with a correlation coefficient of 0.9993 at levels near the detection limits up to at least 100 ng ml−1. The method was successfully applied to the determination of lanthanum in urine samples.