Fd. Rinkema et al., LARGE-VOLUME INJECTIONS IN GAS-CHROMATOGRAPHY ATOMIC-EMISSION DETECTION - AN APPROACH FOR TRACE-LEVEL DETECTION IN WATER ANALYSIS, Journal of chromatography, 678(2), 1994, pp. 289-297
The ruggedness and analytical performance of on-line capillary gas chr
omatography-atomic emission detection (GC-AED) have been studied using
100-mu l injections of sample solutions in ethyl acetate, via a loop-
type interface. A series of organophosphorus compounds were selected a
s test analytes; they were monitored using the carbon, sulphur, nitrog
en, chlorine, bromine and phosphorus channels. The system showed no fl
ame-outs or other maintenance problems even after 300 large-volume inj
ections. The analytical potential of the system, expressed in terms of
repeatability, linearity and minimum detectable amount, was not affec
ted and a 100-fold increase in analyte detectability, in terms of conc
entration units, compared with a conventional 1-mu l injection was obs
erved. As an application, GC-AED was combined off-line with solid-phas
e extraction. Several environmental contaminants were preconcentrated
from river and tap water samples, and 20% (100 mu l) of the ethyl acet
ate eluent were directly analysed. With a sample volume of only 10 ml,
the detection limits of the organophosphorus pesticides typically wer
e ca. 0.1 mu g/l.