Improvement of DEA solid phase extraction column method for the determination of ochratoxin A and B in green and roasted coffee and cereals by HPLC
2010
Kawamura, O., Kagoshima Univ. (Japan). Faculty of Agriculture
Previously reported DEA solid phase extraction column method for the determination of ochratoxin A (OTA) and B (OTB) by Akiyama et al (1997) have some advantages over other methods in low cost, simple, and unnecessary toxic organic solvent, but low recoveries from green coffee and cereals. For improvement, in Akiyama's method, the extraction solvent and the HPLC column were changed to acetonitrile: 0.1%H3PO4 (90 + 1) and a Capcell Pak Csub(18) (MG 4.6 mm i.d. x 250 mm),respectively. In this improved method, the averaged recoveries from samples spiked with 1, 2 and 5 ng OTA and OTB/g in green coffee, brown rice, wheat and corn were 100.5 and 88.9%, 95.3 and 83.6%, 90.5 and 89.7%, and 96.7 and 101.2%, respectively. The limit of detection was 0.2 ng of OTA and OTB/g in green coffee and cereals. The improved DEA method was applied to the determination of OTA and B in roasted coffee. But concomitant matrices in roasted coffee were not adequately clean-upped. The limit of detection was only 2 ng of OTA/g.
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