高效液相色谱法同时测定棉籽油中游离棉酚及其降解产物四甲氧基棉酚含量

Simultaneous Determination of Free Gossypol and Its Degradation Product Tetramethoxy Gossypol in Commercially Available Cottonseed Oil by High Performance Liquid Chromatography

建立高效液相色谱法测定市售棉籽油中游离棉酚及其降解产物四甲氧基棉酚的含量方法,为棉籽油质量控制提供科学依据。采用Inertsil~? ODS-3(250 mm×4.6 mm,5 mm)色谱柱,以甲醇-2%磷酸(85∶15,V/V)溶液为流动相,流速1.0 mL/min,柱温32℃,检测波长235 nm,进样量10 m L。棉酚在0.245~1.226 mg/mL质量浓度范围内线性关系良好(r=0.999 5),精密度检测相对标准偏差为0.88%(n=6),重复性检测相对标准偏差为1.73%(n=6),平均回收率为101.2%,相对标准偏差为1.75%(n=3)。四甲氧基棉酚在0.211~1.056 mg/mL质量浓度范围内线性关系良好(r=0.999 6),精密度检测相对标准偏差为1.56%(n=6),重复性检测相对标准偏差为1.11%(n=6),平均回收率为100.3%,相对标准偏差为1.12%(n=3)。90批市售棉籽油中有25批检测到棉酚,且质量浓度为0.159~1.661 mg/mL,有56批检测到四甲氧基棉酚,且质量浓度为0.093~1.661 mg/mL。该法有良好的准确度、精密度,操作简便,可较广泛用于监控棉籽油的脱毒情况。

This study aimed to establish a high performance liquid chromatography(HPLC) method for the determination of free gossypol and its degradation product tetramethoxy gossypol in commercially available cottonseed oil in order to provide a scientific basis for quality control of cottonseed oil. The chromatographic separation was accomplished on an Inertsil~? ODS-3 column(250 mm × 4.6 mm, 5 mm) using a mobile phase comprised of methanol and 2% phosphoric acid(85:15, V/V)at a flow rate of 1.0 mL/min, and the column temperature was set at 32 ℃. The detection wavelength was 235 nm,and the injection volume was 10 m L. Good linear relationship was achieved for gossypol in the concentration range of0.245–1.226 mg/m L(r = 0.999 5). The relative standard deviation(RSD) of precision and repeatability was 0.88% and 1.73%(n = 6), respectively. The average recovery was 101.2%, with RSD of 1.75%(n = 3). The method also showed a good linear relationship for tetramethoxy gossypol in the concentration range of 0.211–1.056 mg/mL(r = 0.999 6). The RSD of precision and repeatability was 1.56% and 1.11%(n = 6), respectively. The average recovery was 100.3%, with RSD of 1.12%(n = 3). Free gossypol was detected in 25 out of 90 batches of commercially available cottonseed oils in the range of 0.159–1.661 mg/m L, and tetramethoxy gossypol in 56 in the range of 0.093–1.661 mg/mL. This method displayed good accuracy,high precision and easy operation and could be widely used to monitor the detoxification of cottonseed oil.