气相色谱法测定止痒洗剂中苯酚和薄荷脑的含量

目的建立气相色谱(GC)法测定止痒洗剂中苯酚和薄荷脑的含量方法,为止痒洗剂质量控制提供有效的分析手段。方法色谱柱:以HP-5(95%二甲基-5%二苯基聚硅氧烷,0.25 mm×30.0 m)毛细管柱为色谱柱;柱温为60℃;以8℃/min速率升温至160℃,保温10 min,进样口温度180℃,FID检测器,检测器温度300℃。空气流速为300 ml/min,分流比为20∶1。进样量1μl。结果苯酚和薄荷脑的线性范围分别是0.45～9 mg/ml和0.25～5 mg/ml,回归方程分别是A=1.476 9C-0.109 9(r=0.999 9)和A=1.393 7C-0.095 9(r=0.999 9)。苯酚和薄荷脑的平均回收率分别为100.6%(RSD=0.73%)和100.8%相对标准偏差(RSD)=0.76%]。结论该方法简单,结果准确可靠,可用于止痒洗剂中苯酚和薄荷脑的含量测定。

Gas chromatography for determination of phenol and L-menthol in Zhiyang lotion

Objective To establish the methodology for determination of phenol and 1-menthol in Zhiyang Lo- tion by using gas chromatography （GC）. Methods The GC system consisted of an HP-5 （Dimethyl-5% diphenyl polysiloxane, 0.32 mm×30.0 m） capillary column with nitrogen as the carrier gas. The column temperature was set at 60 ℃, with an increase to 160 ℃ within 8 min, followed by a temperature maintenance phase of 10 min. The temper- ature was set at 180 ℃ for sample entry and 300 ℃ for FID assay instrument. Furthermore, the airflow, gas bypass proportion and sample volume was 300 ml/min, 20：1 and 1 μl, respectively. Results For phenol and 1-menthol, the range of linearity was 0.45-9 mg/ml and 0.25-5 mg/ml, the regression equation was A=1.476 9-0.109 9 （r=0.999 9） and A =1.3937-0.0959（r=0.999 9）, and the average recovery was 100.6% （RSD=0.73%） and 100.8% （RSD=76%）, re- spectively. Conclusion The current methodology proves to be simple and reliable and can be applied to determine the concentration of phenol and l-menthol in Zhiyang Lotion.