内标法测定卡波姆中乙酸乙酯和环己烷的残留量

Determination of ethyl acetate and cyclohexane residues in carbomer by internalstandard GC method

建立了卡波姆中环己烷和乙酸乙酯残留量的内标GC测定方法.色谱柱:DB-WAX,30 m×0.32 mm×0.25μm;柱温:50℃维持3 min,然后以5℃/min的速度升至120℃,维持15 min.进样口温度:250℃;FID检测器,温度:250℃;进样量:1μL.空白溶液色谱图中,丁酮、环己烷、乙酸乙酯峰处无干扰.环己烷与相邻峰的分离度约为6;乙酸乙酯与相邻峰的分离度约为2.5.环己烷和乙酸乙酯进样量在0.2~1.2 ng范围内线性关系良好(r=0.999 2和0.999 8).环己烷平均回收率为101.4%,RSD=1.3%(n=6),乙酸乙酯平均回收率为100.6%,RSD=1.1%(n=6).该方法操作简便,灵敏度高,分离度好,结果准确,重复性也比较好,适合卡波姆中乙酸乙酯和环己烷的含量测定.

An internalstandard GC method for the determination of cyclohexane and ethyl acetate residues in carbomer was established in this paper. Separation was performed with DB-WAX column (30 m×0.32 mm×0.25 μm ). Column temperature was set at 50 ℃ for 3 min, then increase to 120 ℃ at rate of 5 ℃/min and maintain for 15 min. Temperature of the injection port was set at 250 ℃. Signal was acquired with FID detector at 250 ℃. Injection volume was 1 μL. No interference at the peaks of butanone, cyclohexane and ethyl acetate in blank solution chromatogram. Resolution between cyclohexane and adjacent peaks was about 6 while ethyl acetate and adjacent peaks was about 2.5. Linear relationship was good (r=0.999 9) at range of 0.2~1.2 ng. Average recovery of cyclohexane was 101.4%, with RSD=1.3%(n=6) and 100.6% for ethyl acetate with RSD=1.1%(n=6). The method is convenient, high sensitivity, accurate and suitable for the determination of ethyl acetate and cyclohexane in carbomer.