Effect of Temperature, Time and Sodium Fluoride Concentration on the Stability of Ethanol in Blood Samples from Male Wistar Rats

Assessment of alcohol abuse is included a large volume of references to the toxicology laboratory. Detection and interpretation of ethanol in blood samples are essential issues in forensic cases, they are important goals for courts. There are numerous biochemical and biological processes which may have significant influence on ethanol concentrations, conditions of the samples (out of the fridge and passed the test of time, temperature and amount of preservative) are effective factors on ethanol concentration. This study was designed to investigate the effects of temperature, time, and sodium fluoride (as a preservative) simultaneously over. In this experimental study, 36 male Wistar rats were divided into three groups of twelve. Three hours before sampling, rates were fed orally with 3 ml of ethanol (diluted with distilled water to one-third). To investigate the effect of sodium fluoride (concentration of 1%, 0.5%, 1.5% w - v), temperature (- 8, 4 and 25° C) and time (zero, 10 and 20 days after sampling). Blood samples were taken from each group. And ethanol were measured with gas chromatography. In order to evaluate the results, the one-way ANOVA test followed by LSD and SNK tests were used to compare groups. And Repeated measure of general liner model was used to detect differences in concentration among different periods. The results showed that at temperatures of -8 and 25° C with protective substances 1 % by weight - volume after the elapse of time, 10 and 20 days, reducing the ethanol concentration is seen. Increase or decrease of ethanol concentration at 4° C with sodium fluoride, 1% after 20 days was not significant. Decrease of ethanol concentration in samples with less protective was more. To evaluate the concentration of ethanol, it is better to store samples of blood and samples at 4° C and sodium fluoride 1%w - v.