Alcohol analysis of stored whole-breath samples by automated gas chromatography.

A new method was developed to apply the advantages of automated gas chromatographic headspace analysis to delayed measurement of alcohol in whole breath (W-B). End-expiratory breath and vapor-alcohol samples were collected in sealed, heated 22-mL glass vials, stored for 0-15 days, and thereafter analyzed for alcohol by automated GC with aqueous calibrators without further sample preparation. The results were compared with those of direct alcohol determinations in closely adjacent breath samples by IR absorptiometry with an Intoxilyzer. The mean difference between 389 paired-sample breath-alcohol concentrations thus determined was close to zero; the correlation coefficient for linear regression of these results plus corresponding blanks was R=0.989. The new method is practical and reliable for law enforcement, clinical, and research applications of delayed breath-alcohol analysis.