Multi-mycotoxin screening reveals separate occurrence of aflatoxins and ochratoxin a in Asian rice.
The determination of important regulated mycotoxins in rice has been reported previously but not in the individual matrix of white, brown, red, and basmati rice with respect to the matrix effect, recovery, and stability. A total of 190 Asian rices were examined for regulated mycotoxin contamination by the LC-ESI-MS/MS method. Significant variation (p < 0.05) in the matrix effect was observed for fumonisins. Methanol improved the limits of detection (LOD) for HT-2 from 50 μg/kg to 2.3 μg/kg by promoting ionization efficiency of the ammonium-adduct. LOD and limits of quantitation ranged from 0.1 to 18 μg/kg and 0.2-31 μg/kg, respectively. All analytes degraded by more than 50% on storage, except fumonisins. Acetic acid (1%) provided significant improvement (p < 0.05) in recovery for all analytes in selected white rice from Thailand and China. Mean recovery ranged from 70 to 120%. RSD values were lower than 15% for all analytes. Five AFB1 and single OTA positive samples were detected. No correlation between mycotoxin contamination and rice species (r = 0) exists.
†Food Safety Laboratory, Applied Sciences Group, Health Sciences Authority, 11 Outram Road, Singapore 169078.
Chee Wei
CW
Lim
‡National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
Tomoya
T
Yoshinari
§Phenomenex, 411 Madrid Avenue, Torrance, California 90501, United States.
Jeff
J
Layne
†Food Safety Laboratory, Applied Sciences Group, Health Sciences Authority, 11 Outram Road, Singapore 169078.
Sheot Harn
SH
Chan
D000348:Aflatoxins / Q000032:analysis*; D001208:Asia; D002851:Chromatography, High Pressure Liquid; D005506:Food Contamination / Q000032:analysis*; D009183:Mycotoxins / Q000032:analysis; D009793:Ochratoxins / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
D000348:Aflatoxins; D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A
LC-ESI-MS/MS; regulated multimycotoxins; rice