Extraction of trace elements in human fluids using cation exchange resin (chelex-100) columns for ICP-MS analysis

A successful metal ion extraction method was developed using cation exchange resin packed disposable micro pipette tip columns for the extraction of trace metal ions in human fluids. Using this method, concentrations of Mn, Ni, Cu, Zn, Cd and Pb ions in human urine were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The main objective of this study was to develop a technique to overcome spectral interferences in ICP analysis of trace elements in biological fluids mainly due to salts present in the samples. The amount of resins packed to the column, amount of eluent needed to extract trace elements, and particle size of the resin were examined to determine conditions for metal extraction. The validity of this technique was evaluated by calculating recoveries of trace element concentrations of above elements in certified standard urine samples and by using the technique for trace metal spiked urine samples. The results revealed that Pb, Cd, Zn, Cu and Mn had good recoveries (about 95%) while Ni & Co had about 80% recovery. It was also found that the recoveries of trace elements depended on the concentrations of relevant elements in the samples.

Journal of the University of Ruhuna 2013 1(2): 23-30