Natural occurrence of aflatoxins,zearalenone and trichothecenes in maize grown in Pakistan

A total of 65 maize grain samples,from 7 maize producing areas of pakistan,were assayed for 14 toxicologically significant mycotoxins viz.,aflatoxin b1 (afb1),aflatoxin b2 (afb2),aflatoxin g1 (afg1),aflatoxin g2 (afg2),zearalenone (zon),deoxynivalenol (don),3acetyl-deoxynivalenol (3a-don),15acetyl-deoxynivalenol (15a-don),nivalenol (niv),t-2 toxin (t-2),ht-2 toxin (ht-2),diacetoxyscirpenol (das),neosolaniol (neos) and fusarenone-x (fus-x). quantification was made by using high performance thin layer chromatography (hptlc). the frequently encountered mycotoxin was afb1 - 27.69% (n=18,range: 5-850 μg kg-1; mean: 192 μg kg-1). other mainly detected mycotoxins include afb2 (18.46%),niv (12.31%),don (9.23%),and 3ac-don (7.69%) with average values of 40,1326,1549,and 356 μg kg-1 respectively. das,t-2 and ht-2 were detected in only 9.23%,6.15% and 6.15% of samples respectively with relatively low concentrations. a co-occurrence phenomenon was observed in 12 (18.46%) samples with a combination of two or maximum three different mycotoxins. it is a first preliminary study report dealing with 14 important mycotoxins simultaneously in maize from main maize growing areas of pakistan.