毛细管顶空进样法测定硫辛酸中有机溶剂残留量

Determination of residual organic solvents in lipoic acid by headspace-gas chromatography

目的:建立以外标法测定硫辛酸中残留量的顶空气相色谱法。方法:用Agilent HP 5毛细管柱(30 m×0.32 mm,0.25μm);载气为N2,柱流量为1.0 mL.min-1,分流比为2∶1,柱温为50℃;检测器为FID,检测器温度250℃;Agilent6890NGC仪和7694E顶空进样器,顶空瓶加热温度为85℃,加热40 min;进样口温度为200℃。结果:乙醇、丙酮、正己烷、乙酸乙酯、环己烷、甲苯的线性范围分别为21.2～190.6,22.1～198.9,2.1～19.1,20.5～184.3,2.2～19.4和2.3～20.6μg.mL-1,相关系数分别为0.994 9,0.998 4,0.993 1,0.999 8,0.992 1和0.999 4;最低检出浓度分别为2.1,2.2,0.2,2.0,0.2和0.2μg.mL-1;平均回收率分别为100.2%(RSD=2.5%),101.3%(RSD=1.4%),102.5%(RSD=1.9%),98.6%(RSD=1.4%),99.7%(RSD=1.8%)和102.8%(RSD=2.1%)。结论:本法简便、灵敏、准确,适用于硫辛酸中有机残留量的测定。

Objective：To establish a headspace-GC method for quantification of residual organic solvents in lipoic acid. Methods： The GC condition was consisted of an Agilent HP-5 capillary column （30 m × 0.32 mm, 0.25μm） with the column temperature of 50 ℃ and the temperature at the injection port of 200 ℃, the carrier gas N2 with the flow rate of 1.0 mL·min^-1 and the split rate of 2： 1, and the FID detector with the temperature of 250 ℃. The headspace sampler of Agilent 7694E was equilibrated at 85 ℃ for 40 min. Results： The analytic outcomes were as follows： a linearity of concentration curves of alcohol, acetone, n-hexane, ethyl acetate, cyclohexane and toluene of within 21.2 -190. 6μg·mL^-1 （r =0.9949）, 22. 1 - 198.9 μg·mL^-1 （r =0.998 4）, 2. 1 - 19. 1 p.g. mL-I （r =0.993 1）, 20.5 - 184. 3μg·mL^-1 （r =0. 999 8）, 2. 2 - 19. 4μg·mL^-1 （r =0. 992 1 ） and 2. 3 -20. 6μg·mL^-1 （r =0. 999 4）, respectively; the mean recovery of 100.2% （RSD = 2.5%）, 101.3% （RSD = 1.4%）, 102.5% （RSD=l.9%）, 98.6%（RSD=1.4%）, 99.7%（RSD=l.8%） and 102.8%（RSD =2.1%）, respectively ; the limit of detection（LOD） of 2.1, 2.2, 0.2, 2.0, 0.2 and 0.2μg·mL^-1 , respectively. Conclusion：This rapid, simple and accurate GC method is useful for quality control of residual organic volatiles in lipoic acid.