GC测定5%薄荷凝胶贴膏中薄荷脑的含量

Determination of Menthol in 5% Menthol Gel Patch by GC

关键词:  凝胶贴膏  薄荷脑  挥发油  超声提取法  气相色谱法

Key words:  hydrogel patch  menthol  volatile oil  ultrasonic extraction  GC

摘要:

目的 建立气相色谱法用于含5%薄荷凝胶贴膏中薄荷脑的含量测定。方法 首先比较挥发油提取法和超声提取法提取样品的优劣，其次采用GC测定薄荷脑含量：以聚乙二醇20000为固定相的毛细管柱(30 m×0.32 mm，0.25 μm)，氮气载气，柱温为140 ℃，FID检测器。结果 选用超声提取法提取样品更加完全。对薄荷脑凝胶贴膏检测方法的方法学考察结果显示，精密度RSD为0.4%，重复性RSD为0.67%，平均回收率为97.02%及其RSD为0.17%，薄荷脑浓度在0.175~2.1 mg·mL^–1内线性关系良好，回归方程为Y=0.802X–0.000 7(r=0.999 9)。用所建立的方法对11批样品进行含量测定，结果均合格。结论 由于凝胶贴膏特有的交联固化过程影响，前处理使用超声提取法比挥发油提取法更可靠、更稳定，建立的GC测定凝胶贴膏中薄荷脑含量的方法可靠、稳定、重现性好，可用于薄荷脑凝胶贴膏的质量控制。

Abstract:

OBJECTIVE To establish a GC method for the determination of menthol in 5% menthol hydrogel patch. METHODS Firstly, the pretreatment methods of volatile oil extraction and ultrasonic extraction were compared. Sencondly, the content of menthol was determined by GC:using capillary column with polyethylene glycol 20000 as stationary phase (30 m×0.32 m, 0.25 μm); nitrogen as the carrier gas, with column temperature of 140℃, and FID detector as the detector. RESULTS Sample could be well extracted by ultrasonic extraction. The methodological investigation of the detection method of menthol gel patch showed that the RSD of precision was 0.4%, the RSD of repeatability was 0.67%, the average recovery rate was 97.02% with RSD of 0.17%, the linearity was good within the menthol concentration range of 0.175-2.1 mg·mL^-1 and the regression equation was Y=0.802X-0.000 7(r=0.999 9). Then 11 batches of the product samples were determined by the established method, and all the results were qualified. CONCLUSION Because of the influence of the cross-linking and solidity of hydrogel patch, the ultrasonic extraction is more reliable and stable than the volatile oil extraction in pretreatment. The established GC method is reliable, stable and reproducible for the determination of menthol in hydrogel patch. It can be used for the quality control of menthol hydrogel patch.