OPTIMIZATION OF THE ELECTROKINETIC SAMPLE INTRODUCTION IN CAPILLARY ELECTROPHORESIS FOR THE ULTRA-TRACE DETERMINATION OF ANIONS ON SILICON-WAFER SURFACES
T. Ekmann et al., OPTIMIZATION OF THE ELECTROKINETIC SAMPLE INTRODUCTION IN CAPILLARY ELECTROPHORESIS FOR THE ULTRA-TRACE DETERMINATION OF ANIONS ON SILICON-WAFER SURFACES, Chromatographia, 45, 1997, pp. 301-311
Citations number
26
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
A capillary electrophoretic method for the ultra trace determination o
f anions on silicon wafer surfaces is presented. In several sets of ex
periments designed according to the methodology of Taguchi, electrokin
etic sample introduction with transient isotachophoretic preconcentrat
ion was simultaneously optimized for peak height, peak area, peak asym
metry, efficiency, peak resolution, and reproducibility of migration t
ime and peak area. The blank reading of the method showed no cross con
tamination. Thus, a detection limit of 10 nmol L-1 and a linear range
from 50 to 500 nmol L-1 were obtained and verified by two independent
instruments. Furthermore, the method was applied to the determination
of anions on wafers from a regular production line wetting the whole w
afer surface with ultrapure water. The capillary electrophoretic resul
ts agree with those obtained by ion chromatography.