Determination of V, Cr, Cu, As, and Pb Ions in Water and Biological Samples by Combining ICP-MS with Online Preconcentration Using Impregnated Resin.

A method was developed for detection of V, Cr, Cu, As, and Pb in water and biological samples by combining online flow injection and preconcentration with inductively coupled plasma-MS. The 2-nitroso-1-naphthol-4-sulfonic acid (Nitroso-S) impregnated MCI GEL CHP20P resin was prepared as an enrichment sorbent. Some parameters affecting the efficiency of the preconcentration process were investigated in the experiment, including the pH and volume of sample solution, the flow rate for sample loading, the type and concentration of eluent, and the influence of co-existing ions. Under the optimal experimental conditions, the enrichment factor and LOD (3s) of chosen metal ions V, Cr, Cu, As, and Pb were in the ranges of 71-268 and 4.89-23.76 ng/L, respectively. Based on 11 repeated measurements of standard solutions (1.0 μg/L), the RSD of the ions ranged from 1.2 to 2.9%. The detection procedure was also performed for analyzing two certified reference materials, GBW 08607 (water) and GBW 10052 (green tea), as well as environmental water and biological samples. Good agreement with certified values and high recoveries have demonstrated improved accuracy of the proposed method.