Comparison of two different clean - up procedures for liquid chromatographic determination of ochratoxin A in raisin

In this study, two different procedures; one using immunoaffinity clean - up and another using mycosep clean- up columns were used. The immunoaffinity and mycosep columns used in our study were Ochra Test; Ochraprep and the new mycosep 229 ochra respectively. In all procedures, separations were carried out by high performance liquid chromatography and fluorescence detection. The mean recovery of OTA using the procedure with mycosep column at spiking level of 30 and 40 pg/kg were 65.1 % with a RSD 11.92 % and 84,52 % with a RSD 9.97 % respectively. The mean recovery of OTA in the other procedures with raisin samples purified on immunoaffinity column in spiking levels; 7.5,10,15,20 and 25 pg/kg varied from 50.96 % to 100.08 % with the RSD ranged 5.35% to 36.43%. The limit of detection for the method of ochratoxin A in rasin purified with mycosep and immunoaffinity column were 20 and 5 pg/kg, respectively