[Determination of acrylic acid in workplaceair by on-line methylationgas chromatography]

A method to determine acrylic acid in workplace air was developed by on-line methylation gas chromatography. Methods: the samples were absorbed by solvent desorption silica gel tube and desorbed by methanol. Desorption fluid in the injector at 350 ℃ in the presence of an organic alkali tetramethylamine hydroxide (TMAH, 25% methanol) , allowed quantitative analysis of acrylic acid as its corresponding methyl derivative by gas chromatography. Results: calibration curve of the method was linear within the range 0-258.4 mg/L and showed good linearity with r=0.999 4. The determination limit of the method was 0.9 mg/L, and the minimum detection concentration was 0.06 mg/m(3) (collect 15 L air) . The relative standard deviation (RSD) was 2.2%-2.7% (n=5) . Recoveries were between 96.9-101.6%. Conclusion: the results prove on-line methylation gas chromatography is an accurate, simple and high sensitive method for determining acrylic acid in workplace air.