A. Tangerman, HIGHLY SENSITIVE GAS-CHROMATOGRAPHIC ANALYSIS OF ETHANOL IN WHOLE-BLOOD, SERUM, URINE, AND FECAL SUPERNATANTS BY THE DIRECT-INJECTION METHOD, Clinical chemistry, 43(6), 1997, pp. 1003-1009
A highly sensitive, reproducible, and rapid gas chromatographic method
for ethanol determination in various biological specimens (human whol
e blood, serum, urine, and fecal supernatants) was developed. The meth
od involves direct injection of the biological specimen into the gas c
hromatograph, without any pretreatment. Contamination of the gas chrom
atographic column with nonvolatile material was prevented by the use o
f a glass liner in the injector. This liner, which acted as a precolum
n, was partly filled with small glass beads. Injection was performed i
n between the glass beads. More than 50 injections of the various biol
ogical specimens could be done before the liner had to be replaced by
a new one. This injection technique between glass beads allows direct
injection of large sample volumes up to 10 mu L without disturbing the
gas chromatographic separation. Injection of these large sample volum
es made the method very sensitive. The detection limit for ethanol amo
unted to 0.1 mg/L (2 mu mol/L) when using an injection volume of 5 mu
L. Attention has also been paid to simultaneously monitoring ethanol,
methanol, acetaldehyde, and acetone in blood and urine of control subj
ects.