Determination of vanadium, molybdenum and tungsten in complex matrix samples by chelation ion chromatography and on-line detection with inductively coupled plasma mass spectrometry

In this work, two kinds of chelating resin, bis(2-aminoethylthio)methylated resin (BAETM) and gamma-aminobutyrohydroxamate resin (gamma-ABHX) were synthesized. Of these, the former has a hydrophobic skeleton, and the latter a hydrophilic skeleton. The functionalities of each were 0.91 and 2.21 mmol g(-1), respectively. The chelating behavior of these resins towards vanadium, molybdenum and tungsten as a function of pH was studied. To perform trace metals analysis in complex matrices, a hyphenated method-chelation ion chromatography (CIC) coupled on-line detection with inductively coupled plasma mass spectrometry (ICP-MS) was developed. With a BAETM resin column (5 x 0.4 cm i.d.) as the separator, a sample volume of 20 mul, nitric acid (pH 1.5) as the eluent and a flow rate of 1 ml min(-1), the detection limits for the determination of vanadium, molybdenum and tungsten were lower than 0.05 ng ml(-1) and the linear ranges were up to 100 ng ml(-1) for each element. By increasing the injected sample volume to 250 mul, the resin concentrator improved the detection limit to 0.01 ng ml(-1). For the determination of these elements (5 ng ml(-1) for each) spiked in artificial sea water samples, gamma-ABHX resin column (3 x 0. 6 cm i.d.) demonstrated well resolved peak separation between the analytes and the matrix elements-calcium and magnesium, by using sodium nitrate (10 ml, 10(-4) M) as the eliminator. (C) 2002 Elsevier Science B.V. All rights reserved.