A headspace gas chromatography (HSGC) method was established for the determination of residual methanol, isopropanol, methyl ethyl ketone, ethyl acetate and isobutanol in sucrose fatty acid esters. Samples were directly injected into the headspace. The chromatographic analysis was performed on a DB-1 column (60 m × 530 μm, 1 μm) equilibrated for 40 min at 80 ℃. The results showed that the calibration curves for the five solvents were linear in the range of 0.05–10.00 μg, with correlation coefficients greater than 0.999, and the limits of quantitation (LOQ) for methanol, isopropanol, methyl ethyl ketone, ethyl acetate and isobutanol were 0.024 4, 0.019 7, 0.022 7, 0.024 5 and 0.019 2 mg/kg, respectively. The average recoveries for all analytes were in the range from 81.7% to 96.8%, and the relative standard deviation (RSD) for precision ranged from 1.90% to 4.52%. The pretreatment method was simple and rapid, with good recovery and precision, and was suitable for the analysis of the five residual solvents in sucrose fatty acid esters. A total 20 lots of of sucrose fatty acid ester samples were detected by the proposed method. The residues of three solvents in 17 of them met the requirements of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The detection rate of methanol was highest (80%), and methanol was the major solvent retained in the lipophilic samples at a level up to 9.42 mg/kg. More solvents were detected in the hydrophilic samples at lower levels.

In this study, headspace gas chromatography-mass spectrometry (HS-GC-MS) was used to accurately identify and quantify ethylene oxide and 2-chloroethanol in milk and dairy products (liquid milk, fermented milk, infant formula milk powder, and ice cream). The sample was diluted to a constant volume in a headspace bottle and balanced at 90 ℃ for 20 min, and the extract was separated on a DB-624 capillary column (60 m × 0.32 mm, 1.8 μm) with temperature programming. Ethylene oxide and 2-chloroethanol were detected using an electrospray ionization (ESI) source in the selected ion monitoring (SIM) mode. Quantitation was carried out using matrix-matched calibration curves. Good linearity was obtained in the range of 0.1–10.0 mg/L (R2 ≥ 0.99). The limits of detection of ethylene oxide and 2-chloropropanol in milk, fermented milk and ice cream were 0.12 and 0.60 mg/kg, respectively. At three spiked levels, the average recoveries of the two compounds were between 75.9% and 101.6%, with relative standard deviations (RSD) less than 10%. This method is precise and accurate, and can meet the requirements for the detection of milk and dairy products with a complex matrix.