APPLICATION OF TERTIARY-AMINES FOR ARSENIC AND SELENIUM SIGNAL ENHANCEMENT AND POLYATOMIC INTERFERENCE REDUCTION IN ICP-MS ANALYSIS OF BIOLOGICAL SAMPLES
A. Krushevska et al., APPLICATION OF TERTIARY-AMINES FOR ARSENIC AND SELENIUM SIGNAL ENHANCEMENT AND POLYATOMIC INTERFERENCE REDUCTION IN ICP-MS ANALYSIS OF BIOLOGICAL SAMPLES, Fresenius' journal of analytical chemistry, 355(7-8), 1996, pp. 793-800
Water soluble tertiary amines enhance signals and decrease polyatomic
chloride interferences in the direct inductively coupled plasma - mass
spectrometric (ICP-TUIS) determination of As and Se in biological sam
ples. Preliminary experiments with amine concentrations and nebulizer
flow rates produced element and interference signal intensity changes.
Arsenic and Se ICP-MS determination parameters have been optimized by
a simplex procedure with amines in an argon plasma or without amines
but with addition of N-2, to the Ar. Variables include RF (radio frequ
ency) power, nebulizer gas flow rate, intermediate gas flow rate, and
amine concentration or nitrogen gas flow rate. Detection limit, minimi
zation of polyatomic ion intensities, and reproducibility have been ev
aluated as reponse factors. The signal enhancement and element-to-mole
cular interference ratios differ to some extent with analyte intensity
optimum operating conditions. The detection limits with addition of n
itrogen (16 pg mL(-1) for As and 180 pg mL(-1) for Se) or of amines (8
pg mL(-1) for As and 120 pg mL(-1) for Se) and the extent of chloride
interference minimization were compared. Amines addition was more ben
eficial. Biological standard reference materials and food and fecal sa
mples were analyzed following different sample dissolution procedures.