LOW-TEMPERATURE ELECTROTHERMAL VAPORIZATION OF 8-HYDROXYQUINOLINATE COMPLEX FOR DETERMINATION OF TRACE VANADIUM BY ICP-AES

A trace amount of vanadium was vaporized as 8-hydroxyquinolinate compl ex by using a low-temperature tungsten boat furnace for sample introdu ction in ICP-AES. Experimental results suggest that vanadium was vapor ized as vanadium(III) 8-hydroxyquinolinate complex. Vanadium(V) and va nadium(IV) were reduced in the heating process before vaporization. Th e operating conditions were optimized, and the effects of foreign ions were investigated. The existence of tin(II) ion in sample solution wa s found to enhance the emission intensity of vanadium, improve the pre cision of the proposed method, and also suppress the interferences fro m other foreign ions. The detection limit in the presence of 5 mu g ti n(II) was determined to be 4 pg, and in the absence of tin(II), 7 pg, of vanadium. Sub-mu g L(-1) levels of vanadium in sample solution coul d be determined by the proposed method. The precisions in relative sta ndard deviation (% RSD) for 100 pg of vanadium under the same conditio ns described above were 1.9% and 4.1%, respectively. The contents of v anadium in some standard steel and rock samples determined by the prop osed method were in good agreement with their certified values.