[Determination of methanol and acetaldehyde in the air of workplace by solvent desorption-headspace gas chromatography].

Objective: To establish a solvent desorption-headspace gas chromatography method for simultaneously determining methanol and acetaldehyde in the air of the workplace. Methods: From June to August 2024, air samples from the workplace were collected using solvent desorption silica gel tubes. After desorption with pure water, the samples were subjected to headspace injection, and separated using a TG-WAX gas chromatography column. The contents of methanol and acetaldehyde were determined using a hydrogen flame ionization detector (FID) , and the detection limits, recovery rates, and other indicators of the method were analyzed. Results: After desorption with 10.0 ml of pure water and subsequent headspace gas chromatography analysis, good linearity was demonstrated for both methanol and acetaldehyde, with correlation coefficients exceeding 0.999. The detection limits of the method were 0.10 and 0.15 mg/L, respectively, and the minimum detectable concentrations were 0.7 and 1.0 mg/m(3) (with a sampling volume of 1.5 L) . The relative standard deviation of precision was 0.92% to 1.45%, the average recovery rate was 97.80% to 101.50%, the desorption efficiency was 95.11% to 97.09%, and the samples could be stored at room temperature for at least 5 days. Conclusion: The solvent desorption-headspace gas chromatography method for the determination of methanol and acetaldehyde is simple, rapid, accurate, and precise, and is suitable for the simultaneous determination of methanol and acetaldehyde in the air of the workplace, meeting the detection requirements for harmful substances in the workplace air.