Determination of chloroacetic acid in workplace air by silanization-gas chromatography

Abstract

Objective: A method to determine acrylic acid in workplace air was developed by silanization-gas chromatography. Methods: In March 2020, chloroacetic acid in air were absorbed by silica gel tube, the samples were dried, then were desorbed and silanized by acetonitrile: N, O-bis (trimethylsilane) trifluoroacetamide (2∶1, V/V) at room temperature, allowed quantitative analysis of chloroacetic acid as its silanization product by gas chromatography. Results: Calibration curve of the method was linear within the range 0-162.8 μg/ml and showed good linearity with linear equation: y=0.011 8x, r=0.999 7. The determination limit of the method was 0.8 μg/ml, and the minimum detection concentration was 0.05 mg/m(3) (collect 15 L air) . The relative standard deviation (RSD) was 0.5%-1.3% (n=5) . Recoveries were between 98.6%-101.2%. Conclusion: The results prove silanization-gas chromatography is an accurate, simple and high sensitive method for determining chloroacetic acid in workplace air.