Rapid analysis of aflatoxins B1, B2, and ochratoxin A in rice samples using dispersive liquid-liquid microextraction combined with HPLC.
A novel, simple, and rapid method is presented for the analysis of aflatoxin B1, aflatoxin B2, and ochratoxin A in rice samples by dispersive liquid-liquid microextraction combined with LC and fluorescence detection. After extraction of the rice samples with a mixture of acetonitrile/water/acetic acid, mycotoxins were rapidly partitioned into a small volume of organic solvent (chloroform) by dispersive liquid-liquid microextraction. The three mycotoxins were simultaneously determined by LC with fluorescence detection after precolumn derivatization for aflatoxin B1 and B2. Parameters affecting both extraction and dispersive liquid-liquid microextraction procedures, including the extraction solvent, the type and volume of extractant, the volume of dispersive solvent, the addition of salt, the pH and the extraction time, were optimized. The optimized protocol provided an enrichment factor of approximately 1.25 and with detection of limits (0.06-0.5 μg/kg) below the maximum levels imposed by current regulations for aflatoxins and ochratoxin A. The mean recovery of three mycotoxins ranged from 82.9-112%, with a RSD less than 7.9% in all cases. The method was successfully applied to measure mycotoxins in commercial rice samples collected from local supermarkets in China.
Key Laboratory of Natural Pesticide and Chemical Biology, South China Agricultural University, Ministry of Education, Guangzhou, P. R. China.
Xian-Wen
XW
Lai
Dai-Li
DL
Sun
Chun-Qiang
CQ
Ruan
He
H
Zhang
Cheng-Lan
CL
Liu
D016604:Aflatoxin B1 / Q000032:analysis* / Q000302:isolation & purification; D000348:Aflatoxins / Q000032:analysis* / Q000302:isolation & purification; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D059627:Liquid Phase Microextraction / Q000379:methods*; D009793:Ochratoxins / Q000032:analysis* / Q000302:isolation & purification; D012275:Oryza / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry
D000348:Aflatoxins; D009793:Ochratoxins; C025589:ochratoxin A; C029753:aflatoxin B2; D016604:Aflatoxin B1
Aflatoxins; Dispersive liquid-liquid microextraction; High-performance liquid chromatography; Ochratoxin A; Rice