Makara Seri Sains (Nov 2010)
DOWNSIZED CHELATING RESIN-PACKED MINICOLUMN PRECONCENTRATION FOR MULTIELEMENT DETERMINATION OF TRACE METALS BY ICP-MS
Abstract
Chelating resin-packed minicolumn preconcentration was used for multielement determination of trace metals inseawater by inductively coupled plasma mass spectrometry (ICP-MS). The chelating resin-packed minicolumn wasconstructed with two syringe filters (DISMIC 13HP and Millex-LH) and an iminodiacetate chelating resin (Chelex 100,200-400 mesh), with which trace metals in 50 mL of original seawater sample were concentrated into 0.50 mL of 2 Mnitric acid, and then 100-fold preconcentration of trace metals was achieved. Then, 0.50 mL analysis solution wassubjected to the multielement determination by ICP-MS equipped with a MicroMist nebulizer for micro-samplingintroduction. The preconcentration and elution parameters such as the sample-loading flow rate, the amount of 1 Mammonium acetate for elimination of matrix elements and the amount of 2 M nitric acid for eluting trace metals wasoptimized to obtain good recoveries and analytical detection limits for trace metals. The analytical results for V, Mn, Co,Ni, Cu, Zn, Mo, Cd, Pb, and U in three kinds of seawater certified reference materials (CRMs; CASS-3, NASS-4, andNASS-5) agreed well with their certified values. The observed values of rare earth elements (REEs) in the aboveseawater CRMs were also consistent with the reference values. Therefore, the compiled reference values for theconcentrations of REEs in CASS-3, NASS-4, and NASS-5 were proposed based on the observed values and referencedata for REEs in these CRMs
