气相色谱法快速测定橡皮擦中的甲醛

Rapid Determination of Formaldehyde in Eraser by GC

采用柱前衍生-气相色谱法测定橡皮擦中的甲醛。样品经粉碎,过0.180mm筛后,称取2.000 0g,用20mL水于70℃浸提20min,冷却后再超声提取30min,离心。10.0mL提取液中加入2,4-二硝基苯肼0.5mL,于70℃衍生反应15min,冷却后用5mL甲苯萃取2次,萃取液经DB-5色谱柱分离,采用电子捕获检测器对甲醛衍生物进行检测。甲醛的线性范围为0.105~10.5mg·L^(-1),检出限(3S/N)为0.01mg·L^(-1),加标回收率在88.6%~92.4%之间。测定值的相对标准偏差(n=6)为2.1%。应用该方法测得32种橡皮擦样品中的甲醛的质量比在0.135~48.5mg·kg^(-1)之间。

GC combined with pre-column derivatizaiton was used to determine formaldehyde in eraser. After heing crushed to the size of 0. 180 ram; 2. 0000 g of sample was extracted with 20 mL water at 70 ℃ for 20 min and cooled, and then extracted ultrasonically for 30 min After centrifugation, 10.0 mL of the extract derivatized with 0. 5 mL of 2,4-dinitrophenylhydrazine at 70℃ for 15 min. The solution was cooled and then extracted with 5 mL of toluene for two times. The extract was separated on a DB-5 chromatographic column and formaldehyde derivative was detected by electron capture detector. The linearity range of formaldehyde was 0. 105--10.5 mg·L^- 1 and the detection limit （3S/N） was 0. 01 mg · L-1. Recovery rates obtained by standard addition method were in the range of 88. 6%-92. 4%, and RSDs （n=6） was 2. 1X. This method was applied to the determination of formaldehyde in 32 kinds of erasers, giving results in the range of 0. 135--48.5 mg· kg^- 1.