A Simple Approach to Gas Chromatographic Microanalysis of Alcohols in Blood and Urine by a Direct-Injection Technique

An ultra-micro method utilizing direct sample Injection Is de-scribed for the simultaneous Identification and quantification of ethanol, methanol, Isopropanol, and acetone In blood and urine by gas chromatography. AIIquots of whole blood, serum, plasma, or urine and an Internal standard, 1-propanol, are mixed together In equal parts. One microllter of the mixture Is then Injected Into a Shimadzu GC-4BM gas chro-matograph equipped with 8 flame Ionization detector. The glass column, 3-mm I.d. x 2-m long, Is packed with 0.2% Carbowax 1500 on 801100 Carbopak C (Supalco, Inc., Belle-lento, PA #SP-1827). The column Is fitted with s precolumn glass insert filled with a loosely packed sllanlzed glass wool plug that 8ct8 as a trap for the nonvolatile protein material of the blood end urine specimens. The optimal operating con-dltions for the gas chromatograph are: column temperature 120 ~ Injector temperature 100"C; carrier gas flow 20 ml/mln; hydrogen and sir pressure set st optimal conditions for 8 hydrogen flame. The relative retention times of the eluted compounds to the Internal standard, l-propsnol, are: ethanol 0.51; methanol 0.37; acetone 0.65; and Isopropanol 0.78. A simple micro method Is also described for the celiac-lion and storage of blood for alcohol determination. The tech-niques provide a rapid, reproducible procedure for the indi-vidual or simultaneous ultra-micro analysis of alcohols com-inertly encountered in clinical or forensic toxicology