Determination of ochratoxin A in wheat after clean-up through a DNA aptamer-based solid phase extraction column

► SPE columns containing a DNA aptamer with high affinity and specificity to OTA were prepared. ► Good performance results in the range 0.4-500 ng of OTA were obtained. ► Aptamer-SPE columns were successfully applied to the clean-up of OTA from wheat samples. ► Recovery results at spiking levels of 0.5-50 ng/g were 74-88%. ► Performances of aptamer-SPE columns were comparable to those of IMA columns.