超声提取-反相高效液相色谱法测定棉仁中游离棉酚

用超声提取对棉仁进行预处理,探讨了影响棉酚提取率的因素,确定其最佳提取条件为:料液比0.1∶15(g/mL),提取时间50min,超声功率90W。在最佳提取条件下,棉仁中游离棉酚的平均提取率为6.3282 mg/g。利用反相高效液相色谱(RP-HPLC)法测定棉仁中游离棉酚含量,使用SinoChrom ODS-BP C18色谱柱(200×4.6mm,5μm),流动相为甲醇-1%磷酸水溶液(体积比85∶15),流速为0.9mL/min,紫外检测波长为238nm。结果表明,棉酚在0.0044～0.0352mg/mL范围内与色谱峰面积呈良好线性关系,线性相关系数为0.9998,平均加标回收率在98.80%～99.03%之间。该法快速、灵敏、准确,适用于棉仁中游离棉酚的定量分析。

Determination of Free Gossypol Content in Cottonseed by Reversed Phase-High Performance Liquid Chromatography with Ultrasonic Extraction

Ultrasonic extraction as a pretreatment method was used for gossypol extraction from cottonseed.By using orthogonal test,the scope and the best conditions of influencing factors on gossypol yield were confirmed.The highest extraction yield can be obtained when the ratio of sample weight to solvent volume was 0.1∶15(g/mL),the extraction time and the ultrasound power were 50min and 90 W,respectively.Under the optimized conditions,the extraction amount of free gossypol from cottonseed was 6.3282 mg/g.Reversed phase-high performance liquid chromatography(RP-HPLC)was used to determine free gossypol content in cottonseed.Chromatographic conditions were as follows:SinoChrom ODS-BP C18column(200×4.6mm,5μm)was used,the mobile phase consisted methanol-1%phosphoric acid solution(85∶15),gossypol was determined at 238nm,at flow rate of 0.9mL/min.The linear range of gossypol was 0.0044～0.0352mg/mL,and the average recovery ranged from 98.80% to 99.03%.This method is rapid,sensitive,accurate,and applicable in quantitative analysis of free gossypol in cottonseed.