THE EFFECT OF STORAGE AT VARIOUS TEMPERATURES ON BLOOD-ALCOHOL CONCENTRATION

There is a paucity of data available on the effect of storage on blood alcohol concentration (BAG) at elevated temperatures. Changes in seru m alcohol concentration (SAG) and BAC were studied. Serum samples spik ed with alcohol in the presence or absence of preservative were stored at 26.7 degrees, 32.2 degrees or 37.8 degrees C respectively. Serum a lcohol concentrations were determined daily on days 1 through 14, and on days 21 and 35. Under these controlled conditions, no significant c hange in SAC was observed at the aforementioned temperatures. Whole bl ood samples submitted from outside agencies were initially analyzed (d ay 1), then stored for 35 days at different elevated temperatures befo re a second analysis. The average loss in BAC was 19.20 +/- 15.6, 9.95 +/- 5.7, and 15.60 +/- 6.9% when the samples were stored at 26.7, 32. 2 and 37.8 degrees C, respectively. The alcohol loss from whole blood samples may be attributed to chemical oxidation rather than to elevate d temperatures. It is, therefore, concluded that a whole blood sample obtained from a living individual and stored in a locker, glove compar tment or other environment where the temperature is elevated, may lose 10-19% of its alcohol content over 35 days of storage. On the other h and, when a serum or plasma sample is exposed to the same environment, no significant change in SAC was observed. The utility of this inform ation is significant to the forensic toxicologist. The results of this study suggest that a whole blood sample analyzed after exposure to el evated temperature may have had, originally, a higher BAC.