Elemental speciation by liquid chromatography-inductively coupled plasma mass spectrometry with direct injection nebulization.
A new version of the direct injection nebulizer (DIN) is used to interface liquid chromatographic (LC) separations with element-selective detection using inductively coupled plasma mass spectrometry (ICP-MS). The DIN injects all of the sample into the ICP and has a dead volume of less than 1 microliter. Charged species of arsenic and tin are separated as ion pairs on a micro-scale (1 mm i.d.), packed, reversed-phase column. Detection limits are 0.2-0.6 pg for arsenic and 8-10 pg for tin. For methanol + water eluents, the signal is highest at 25% methanol and stays within 25% of this maximum as the methanol fraction is varied from 20 to 80%. Compared with LC-ICP-MS with conventional nebulizers, the absolute detection limits and chromatographic resolution are substantially superior, and the dependence of analyte signal on solvent composition is somewhat less severe with the DIN.
Shum
S C
SC
Ames Laboratory-US Department of Energy, Department of Chemistry, Iowa State University, Ames 50011.
Neddersen
R
R
Houk
R S
RS
D001152:Arsenicals / Q000032:analysis*; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D009947:Organotin Compounds / Q000032:analysis*
D001152:Arsenicals; D009947:Organotin Compounds