关键词: 捕集肼顶空-气相色谱法, 聚对苯二甲酸乙二醇酯, 瓶装水, 乙醛, 检出限

Abstract: This paper established a methodology for determining the content of acetaldehyde in the bottled water in PET bottles by automatic headspace-trap gas chromatography. This methodology includes the following steps: 10 mL of water sample was taken and then 4 g of sodium chloride was added into the sample. The sample was enriched by trap to improve sensitivity for gas chromatographic analysis. The temperature of headspace oven was set as 80 ℃, the needle temperature as 130 ℃, the transmission line temperature as 135 ℃, the balance time of oven as 20 min, the trap adsorption temperature as 30 ℃, the desorption temperature as 280 ℃, the cycle number as 3 times, the GC injection temperature as 200 ℃, and the FID temperature was set as 200 ℃. Moreover, the HP-INNOWAX column was used with the programmed temperature elevation in the temperature range of 50~100 ℃. Moreover, the linearity range was kept within 50 μg/L with a detection limit of 5 μg/L, and the recovery and precision were tested at two concentration levels of 20 μg/L and 50 μg/L. The average recovery was measured to be 92.9 % and RSD values were determined as 2.08 %~4.01 % with a correlation coefficient of 6. This method is simple, rapid, sensitive and reproducible and can be used for the determination of acetaldehyde in the bottled water.

Key words: automatic headspace-trap gas chromatography, polvethvlene terephthalate, bottled wa ter: acetaldehyde; detection limit