Shuyu Liu1, Feng Qiu, Meihua Yang. 1. Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Peking Union Medical College, Beijing 100094, China.
Abstract
UNLABELLED: To determine the contents of aflatoxin B1, B2, G1 and G2 in Nelumbinis Semen using on-line post-column photochemical derivatization-HPLC-FLD method and verify the method by LC-MS method. METHOD: The samples were extracted with MeOH-H2O (80: 20) and purified with inmunoaffinity column, aflatoxins were analyzed by HPLC-FLD with post-column photochemical derivatizaton. The positive samples were further confirmed by LC-MS/MS. RESULT: On optimum conditions, aflatoxin B1, G1 ranging 0.3-30 mg x L(-1) showed a good linear relationship with aflatoxin B2, G2 ranging 0.09-9.0 mg x L(-1) with r >0.999 9. The recoveries ranged between 86.7% and 99.1%, with RSDs all bellow 4.87%. LOD of aflatoxin B1, B2, G1 and G2 were 0.08, 0.03, 0.10, 0.03 microg x kg(-1), respectively. Among 20 Nelumbinis Semen samples, 14 were found to contain aflatoxin B1 ranging from 0.40 to 586 microg x kg(-1). The total content of aflatoxin B1, B2, G1 and G2 were between 0.40 and 602.5 microg x kg(-1). By LC-MS/MS method, the same fragment ions were founded in samples and the control group at the same retention times, ruling out the possibility of false positive samples. CONCLUSION: The method is simple, highly sensitive and reproducible for the determination of aflatoxins in Nelumbinis Semen.
UNLABELLED: To determine the contents of aflatoxin B1, B2, G1 and G2 in Nelumbinis Semen using on-line post-column photochemical derivatization-HPLC-FLD method and verify the method by LC-MS method. METHOD: The samples were extracted with MeOH-H2O (80: 20) and purified with inmunoaffinity column, aflatoxins were analyzed by HPLC-FLD with post-column photochemical derivatizaton. The positive samples were further confirmed by LC-MS/MS. RESULT: On optimum conditions, aflatoxin B1, G1 ranging 0.3-30 mg x L(-1) showed a good linear relationship with aflatoxin B2, G2 ranging 0.09-9.0 mg x L(-1) with r >0.999 9. The recoveries ranged between 86.7% and 99.1%, with RSDs all bellow 4.87%. LOD of aflatoxin B1, B2, G1 and G2 were 0.08, 0.03, 0.10, 0.03 microg x kg(-1), respectively. Among 20 Nelumbinis Semen samples, 14 were found to contain aflatoxin B1 ranging from 0.40 to 586 microg x kg(-1). The total content of aflatoxin B1, B2, G1 and G2 were between 0.40 and 602.5 microg x kg(-1). By LC-MS/MS method, the same fragment ions were founded in samples and the control group at the same retention times, ruling out the possibility of false positive samples. CONCLUSION: The method is simple, highly sensitive and reproducible for the determination of aflatoxins in Nelumbinis Semen.