Sample suitability and stability in different blood collection tubes for methanol, ethanol, isopropanol, acetone and glycols analysis

Abstract

AimTo systematically examine the sample suitability and stability for volatile alcohols (methanol, ethanol and isopropanol with its metabolite acetone) and glycols (ethylene/propylene glycols, EG/PG) in different collection tubes.MethodTwo pools of whole blood were created and spiked with two levels of volatile alcohols and EG/PG. The spiked whole blood was added to six different blood collection tubes and were kept at different storage conditions. An aliquot was prepared from baseline replicates. Concentrations of volatile alcohols and glycols were analysed by gas chromatography.ResultsAll blood collection tubes have demonstrated similar performance over different storage conditions, that is, to be statistically insignificant (p>0.05) with the only exception of PG at the high concentration of day 7 at 4°C condition (p<0.05 but clinically insignificant as <clinical acceptable limit (CAL) of 25%). Compared with the baseline, most volatile alcohols showed statistical significance (p<0.05) but were clinically stable for all storage conditions (biases<CAL). Similarly, compared with day 1, most EG/PG were stable up to 28 days at −20°C. Aliquoted samples were clinically stable up to 28 days at −20°C.ConclusionGrey/red/lavender, serum separator tube, plasma separator tube and the newly developed Barricor tubes are all suitable for volatile alcohols and EG/PG analysis. Primary samples are stable for 2 days room temperature, 14 days at 4°C and 28 days at −20°C for volatile alcohols, and 2 days room temperature, 7 days at 4°C, and 28 days at −20°C for EG. Aliquoted samples are stable up to 28 days at −20°C for all volatile alcohols and glycols.