EVALUATION OF A DIRECT-INJECTION NEBULIZER (DIN) FOR LIQUID SAMPLE INTRODUCTION IN HELIUM MICROWAVE-INDUCED PLASMA-MASS SPECTROMETRY (MIP-MS)

A direct-injection nebulizer (DIN) has been evaluated for liquid sampl e introduction in helium microwave-induced plasma mass spectrometry (M IP-MS). A short-term stability test with the direct-injection nebulize r was found to give less than 0.5% RSD for twenty minutes. Isotope abu ndances for K, Ca, Cr, and Se were determined with less than 10% error on all isotopes. All elements have linear dynamic ranges of two to th ree orders of magnitude. Detection limits are low to sub-ppb for all e lements. Ion lens tuning plays an important role in multielement deter minations. Oxide, hydroxide, and doubly charged ions are determined fo r Cr, As, Sr, Cs, Ba, and Pb. The effect of 10% methanol and high-diss olved salts is investigated.