COMPARISON OF CRYOGENIC AND MEMBRANE DESOLVATION FOR ATTENUATION OF OXIDE, HYDRIDE AND HYDROXIDE IONS AND IONS CONTAINING CHLORINE IN INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY
Mg. Minnich et Rs. Houk, COMPARISON OF CRYOGENIC AND MEMBRANE DESOLVATION FOR ATTENUATION OF OXIDE, HYDRIDE AND HYDROXIDE IONS AND IONS CONTAINING CHLORINE IN INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY, Journal of analytical atomic spectrometry, 13(3), 1998, pp. 167-174
Conventional, cryogenic and membrane desolvation methods were compared
with respect to sensitivity, MO+/M+ signal ratios and the aerosol gas
flow rate required to maximize M+ and MO+ signals, Thorium was used t
o represent the actinides, which form relatively strong hydrides and h
ydroxides, The LaO+/La+ ratio is reduced from 0.24% with conventional
desolvation to 0.08% with membrane desolvation and 0.01% with cryogeni
c desolvation, Membrane desolvation reduces ThH+ and ThOH+ 2-fold comp
ared with conventional desolvation, Cryogenic desolvation attenuates T
hH+ 7-fold and ThOH+ 20-fold compared with conventional desolvation, T
he three desolvation methods were also evaluated for the removal of CI
O+ and ArCl+ for the determination of vanadium and arsenic at trace le
vels in the presence of chloride, The density of oxygen atoms is reduc
ed as water vapor is removed, and chloride is also removed, presumably
as hydrogen chloride, The concentration of vanadium in a urine standa
rd reference material was determined by standard additions to be 7 ppb
with cryogenic desolvation and 5 ppb with membrane desolvation, Analy
sis of several nasal wash samples using cryogenic and membrane desolva
tion yielded results that agreed within 5% for the two methods in all
cases except for the sample with the highest V+ concentration.