Effect of different columns and internal standards on the quality assurance of the gas chromatographic determination of blood ethanol.

Abstract

Quality assurance is an essential requirement of clinical and forensic laboratories, especially in the determination of ethanol. Opinions differ as to whether normal gas chromatographic methods should be used with modified procedures, or whether different chromatographic strategies should be adopted, the choice being based entirely on practical considerations. We have evaluated the influence on the blood ethanol determination of the frequently used glass and steel columns, as well as the use of isopropanol and tert-butanol as internal standards. All the different combinations of column type and standard provided accurate and reliable results with no significant deviation. Standardization of the analytical procedure is therefore unnecessary, but international ethanol standards should be analysed sequentially to test the method and the staff performing the analyses in the different laboratories.