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.