顶空毛细管气相色谱法测定新药大黄酸中有机溶剂及溶剂杂质的残留量

Determination of residual organic solvents and solvent impurities in rhein by capillary gas chromatography with headspace sampling

目的建立顶空毛细管气相色谱法，测定中药一类新药大黄酸原料中三氯甲烷及其溶剂杂质二氯甲烷、1，2．二氯乙烷与四氯化碳的残留量。方法采用5％苯基甲基聚硅氧烷毛细管柱（HP．530m×0．32mm，0．25gm），40℃恒温，柱压为88kPa；载气为N2；进样口温度200℃；检测器（ECD）温度300℃；顶空进样；进样量为1mL；分流比为9：1；0．05mol·L^-1的NaOH水溶液为溶解介质。结果在以上色谱条件下，测得各组分在所考察的浓度范围内具有良好线性，r为0．9994～0．9997；平均回收率为90．4％～102．5％；精密度RSD均小于10％；三氯甲烷、二氯甲烷、1，2-二氟乙烷与四氯化碳的最低辁出浓度分别为3．0、24．0、7．5和0．2μg·L^-1。结论本法快速、灵敏、准确，适用于大黄酸原料中有机溶剂残留量的测定。

OBJECTIVE To establish a headspace capillary gas chromatography method for quantification of residual organic solvents and solvent impurities（ chloroform, dichloromethane, 1, 2-dichloroethane, carbon tetrachloride）in rhein. METHODS The determination was performed on a 5 % phenyl methyl siloxane column（HP-5, 30 m × 0.32 mm, 0.25 μm）with a constant column temperature at 40 ℃ and a constant column pressure of 88 kPa. Nitrogen was chosen as the carrier gas. The injection port temperature was 200℃. The ECD detector worked at the temperature of 300 ℃. The headspace injection was applied with the injection volume of 1mL and the split ratio was set at 9：I.NaOH solution（0.05 mol· L^-1） was used as solvent media. RESULTS The results showed good linearity（r = 0. 9994-0. 9997）. The average recoveries were 90.4 %-102.5 % and each RSD was less than 10 %. The minimum detection concentrations of chloroform, dichloromethane, 1, 2-dichloroethane and carbon tetrachloride were 3.0, 24.0, 7.5 and 0.2μg· L^-1, respectively.CONCLUSION This method is simple, sensitive and accurate. It is suitable for determination of organic solvents and solvent impurities in rhein.