Determination of Acetonitrile in High Purity Butadiene by Gas Chromatography with Nitrogen Chemiluminescence Detector

By optimizing chromatographic conditions, the interference of hydrocarbon components on acetonitrile was eliminated. A method for determination of acetonitrile in high purity butadiene by gas chromatography with nitrogen chemiluminescence detector was proposed. The optimized chromatographic conditions were as follows: HP-1 quartz capillary chromatographic column (30 m×0.32 mm, 3.0 μm); helium as carrier gas, at column flow rate of 12.0 mL · min⁻¹; split injection at split ratio of 5∶1; injection volume of 2 mL; initial column temperature of 40 ℃, which was maintained for 3 min, and raised to 200 ℃ at rate of 50 ℃  · min⁻¹ for 2 min. The sample was directly determined according to chromatographic conditions, and external standard method was used for quantification. It was shown that linear relationship between the corresponding peak areas and mass fractions of acetonitrile was found in the range of 0.10-10.00 mg·kg⁻¹, with detection limit of 0.024 9 mg · kg⁻¹. Test for recovery was made on the blank sample at 3 concentration levels, giving results in the range of 101%-108%, with RSDs (n=12) of the determined values less than 6.0%. The method was applied to the analysis of 10 batches of actual samples, with RSDs (n=6) of the determined values less than 6.0%.