LC-MS内标法测定棉籽仁、棉叶及棉茎中棉酚含量

Determination of gossypol in cottonseed, cotton leaves and cotton stalk by LC-MS with internal standard method

目的：建立棉籽仁、棉叶及棉茎中游离棉酚含量的LC-MS内标检测法。方法：以甘草次酸为内标物，采fflYMC—C18色谱柱（150mm×3．0mm，3μm），流动相为乙腈：1％甲酸溶液=80：20，流速O．3mL／min，柱温25℃；电喷雾离子源（ESI），负离子模式，选择性离子监测（SIM），棉酚的检测离子为[M—HI]，m／z516．6，内标甘草次酸的检测离子为[M-H]-，m／z468．9。结果：棉酚质量浓度在1．008-50．40μg／mL范围内呈良好线性关系，加标回收率为90．3％-103．6％，RSD为1．8％～3．7％。结论：该方法灵敏度高、专属性强，样品处理简便易行，可准确测定棉籽仁、棉叶和棉茎中棉酚的含量。

Objective： LC-MS with internal standard method was established for the determination of gossypol in cottonseed, cotton leaves and cotton stalk. Method： Using glycyrrhetinic acid as an internal standard. The chromatographic separation was conducted on a YMC-C18 column （150 mm×3.0 mm, 3 μm） with a mobile phase consisted of acetonitrile and 1% methanoic aid（80：20）, at a flow rate of 0.3 mL/min, the column temperature is 25 ~C. In addition, The condition of mass spectrometry was operated through electrospray ionization, in the selected ion monitoring （SIM） and negative ion mode. The monitoring ions of gossypol were 516.6, The monitoring ions of glycyrrhetinic acid were 468.9. Results： It showed that a good linear relationship between LC-MS peak area and gossypol concentration was obtained over the range of 1.008-50.4 0g/mL, the recoveries of gossypol at three levels were 90.3%-103.6%, with RSD ranged from 1.8% to 3.7%. Conclusion, The method is sensitivity, specificity and simplicity. Therefore it is applicable to the determination of gossypol in cottonseed, cotton leaves and cotton stalk.