两种游离棉酚检测方法对常规棉粕检测的比较

Detection of Free Gossypol Content in Cottonseed Meal by Two Methods

主要针对常规棉籽粕（游离棉酚含量200-1000mg/kg）中游离棉酚含量的检测,用美国油化学家学会官方方法AOCSBa7-58和国标GB13086方法作对比检测,以比较2种方法的差异和对结果的影响。参照AOCSBa7-58制定标准曲线,计算换算因子F1,AOCSBa7-58和GB13086的回收率检验,并选择3种游离棉酚含量梯度的常规棉粕测定游离棉酚含量。AOCSBa7-58标准曲线换算因子F1=0.370,R2=0.999,回收率101.14%,RSD=2.56;GB13086质量吸收系数,游离棉酚为62.5L/（cm·g）,回收率104.98%,RSD=9.85。结果表明,AOCSBa7-58对棉酚及其衍生物的提取充分,检测结果稳定,重复性好;而GB13086对棉酚及其衍生物的提取不稳定,时高时低,造成检测结果的不稳定性,重复性差。建议饲料行业应由AOCSBa7-58代替GB13086检测棉粕及饲料中游离棉酚含量,更能体现棉粕及饲料中＂棉毒素＂的含量。

Free gossypol content in cottonseed meals （Free gossypol content of 200 -1 000 mg/kg） was determined by AOCS recommended Ba7-58 method and national standard GB 13086 method. Referring to AOCS Ba7-58, standard curve was established, and calculate factor F1 was obtained. Rate of recovery was also determined, the free gossypol content in three cottonseed meals having different free gossypol content was determined. According to AOCS Ba7-58 standard curve, F1=0.370, R2=0.999, and rate of recovery= 101.14%. According to mass absorption coefficients in GB 13086 method, the free gossypol content, rate of recovery and RSD were 62.5 L/（cm·g）, 104.98% and 9.85, respectively. The results showed gossypol and its derivates could be fully extracted by the AOCS Ba7-58 method, and the detection was stable and repeatable. Gossypol and its derivates could not be extracted stably by the GB 13086 method, and the detection had poor repeatability. Therefore, we recommended AOCS Ba7-58 method be substituted by GB 13086 method to detect free gossypol content in cottonseed meals in feed industry, and the results can accurately reflect toxic content in cottonseed meals and feed.