OBJECTIVE: To improve the standard detection method for acetonitrile in workplace air. METHODS: Acetonitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatography with flame ionization detection. RESULTS: After the improvement of the method, the linear range of acetonitrile was 1.57-1 574.00 mg/L, and the correlation coefficient was 0.999 98. The detection limit was 0.29 mg/L and the minimum detection concentration was 0.19 mg/m~(3 )(collected sample volume was 1.5 L). The average desorption efficiency was 93.1%-98.9%. The within-run and between-run precision was 2.6%-3.3% and 1.7%-3.6%, respectively. The samples could be stored at room temperature for at least 10 days. CONCLUSION: The improved method is precisied, accurate and simple to operate, which is suitable for determination of acetonitrile in workplace air.