顶空法同时测定液晶材料中4种有机溶剂残留

Simultaneous Determination of Four Residaul Solvents in Liquid Crystal Meterials by Headspace Gas Chromatography

建立了同时测定液晶材料中甲醇、乙醇、丙酮、正庚烷4种残留溶剂的顶空气相色谱分析方法。以AgilentDB-624毛细管色谱柱为分离柱,氢火焰离子检测器检测,外标法定量,并考查了顶空平衡温度、平衡时间等对残留溶剂测定的影响,在已优化的条件下,4种残留溶剂在选择的浓度范围内线性关系良好,相关系数(r)均不小于0.9994,在高、中、低3个加标水平下,平均回收率为94.8%~104.3%,相对标准偏差(RSD)均不大于5.0%,检出限(LOD)为0.25~2.55mg/L,定量限(LOQ)为0.75~7.70mg/L。此方法操作简单,准确度高,适用于液晶材料中多种溶剂的同时检测。

A headspace gas chromatography method for the simultaneous determination of methanol, ethanol, acetone and n-heptane in liquid crystal material trans-propyl dicyclohexyl methylbenzene was established. This method was an external standard method, which with Agilent DB-624 capillary column as separation column and flame ionization detector. The effects of headspace equilibrium temperature and equilibrium time on the determination of residual solvents were also investigated. Under the optimum conditions, the linear relationships of the four residual solvents were good in the selected concentration range, and the correlation coefficients were all not less than 0.999 4. The average recoveries were 94.8%~104.3%, and the relative standard deviations (RSD) were all not more than 5.0% at three levels of high, medium, low standard addition. The limit of detections (LOD) were 0.25~2.55 mg/L and the limit of quantitation (LOQ) were 0.75~7.70 mg/L respectively. This method with simple and high accuracy characters, can be well used for simultaneous determination of various solvents in liquid crystal materials.