DETERMINATION OF TRACE AMOUNTS OF BORON BY MICROWAVE PLASMA PORCH ATOMIC-EMISSION SPECTROMETRY USING AN ONLINE SEPARATION AND PRECONCENTRATION TECHNIQUE

A new system for the determination of trace amounts of boron by flow i njection microwave plasma torch atomic emission spectrometry is propos ed In the system, a strongly acidic cation-exchange column is connecte d in series with a strongly basic anion-exchange column, By the combin ed function of the two columns, interferences (e.g., iron) in the samp le solution are removed and the analytical performance improved, Optim ization studies illustrate the dependence of the analytical signals of boron on various parameters, including observation height, microwave forward power, flow rates and acidities of the sample solution and the eluents in both columns, The effect of concomitant ions on the relati ve emission intensity of boron is also examined. Detection limits of 0 .0055 mg l(-1) at 45 samples h(-1) and 0.0018 mg l(-1) at 20 samples h (-1) with a precision of 4.2% at the 0.020 mg l(-1) level of boron wer e achieved. With sample columns of 1.25 and 5.0 ml, enrichment factors of 22 and 88 were obtained, respectively, The proposed system has bee n applied to the determination of trace amounts of boron in steel samp les and the results obtained were satisfactory.