FIELD: analytical chemistry.
SUBSTANCE: sample of purified ethyl alcohol rectified from food raw materials is used as a calibration sample of ethyl alcohol with minimum concentrations of controlled microimpurities. A calibration sample of the composition of ethyl alcohol with maximum concentrations of microimpurities is obtained by adding 2-5 ml of fusel-etheraldehyde concentrate from all impurities obtained during purification of this alcohol to every 100 ml of the previous sample. Calibration samples of the composition of ethanol with intermediate concentrations of microimpurities greater than in the sample with minimum concentrations of microimpurities and less than in the sample with maximum concentrations of microimpurities are obtained by mixing these samples in the selected proportion of their volumes. Concentrations of microimpurities in all calibration samples are measured in 3-5 replications by the gas chromatographic method of analysis in 2-3 accredited analytical laboratories, the content of microimpurities in the samples is calculated as the arithmetic mean of the measurement results of these indicators, while erroneous measurement results of microimpurities in samples with intermediate concentrations that deviate up or down from the calculated values of these concentrations by value specified by the manufacturer of the calibration samples.
EFFECT: increased stability of composition of standard samples and increased shelf life thereof.
1 cl, 1 tbl, 1 ex
