Simultaneous determination of silver, cadmium, copper, nickel, lead, thallium and zinc in pure water by isotope dilution surface ionization MS.

Abstract

Isotope dilution surface ionization MS has been applied to the accurate determination of Ag, Cd, Cu, Ni, Pb, Tl and Zn contained in purified water at the level of 10-10∼10-11 g kg-1. After spiking with a composite solution of 107Ag, 116Cd, 65Cu, 61Ni, 286Pb, 203T1 and 68Zn, the spiked sample is evaporated to dryness at low temperature under nitrogen. The residue obtained is dissolved in a dilute HNO3 solution. An aliquot of this solution is applied to the mass spectrometer (Hitachi RMU 6) equipped with a surface ionization device incorporating a Re single filament. The present method can detect the presence of minute amounts, i.e., 10-12∼10-15 g of the above elements with an accuracy of 1% in the relative standard deviation and measure these elements in distilled water and even in water purified by sub-boiling distillation method using quartz still specially devised for getting ultrapure water. © 1986, The Japan Society for Analytical Chemistry. All rights reserved.