Identification and Determination of Ochratoxcin A concentration in wheat flour factories in Ahvaz city by using HPLC method

Ochratoxin A (OTA) is the most poisonous of ochratoxins، with nephrotoxicity and carcinogenicity toxic effects. This study was carried out to identify and determine the concentration of OTA in wheat flour produced by four factories in Ahvaz city using HPLC method. Subjects and In order to separation and quantification of OTA in produced wheat flour of 4 factories in Ahvaz، 8 times، each time، one composite samples from wheat flour of each factory which comprising 20 grab samples was taken. An adequate of each sample mixed with methanol- phosphate buffer، filtered; an aliquot of the filtered was diluted and purified by running through a immunoaffinity column. The column was washed with water; then OTA was eluted by methanol. The eluted was concentrated to dryness under a gentle nitrogen stream. Finally، the residue was dissolved in mobile phase and analyzed by HPLC using column (150 mm ×4. 6 mm ID، 5 µm C18 stationary phase) with a fluorescence detector (excitation and emission wavelength was 333 nm 460 nm respectively)، mobile phase of acetonitrile-water-glacial acetic acid (49. 5:49. 5:1) and at flow rate of 1. 5 mL/min The limits of detection and quantification were 0. 0075 and 0. 025 ng/g، respectively. Thirty (93. 75%) out of 32 samples were contaminated with OTA، at concentration ranging from 0. 004 to 0. 809 ng/g، with an average of 0. 09 ng/g. The results showed that all of the samples had lower levels of OTA than maximum tolerable limit of 5 ng/g assigned by Institute of Standard and Industrial Research of Iran (ISIRI) for wheat and WHO guidelines.