In particular,
a crude extract was obtained from meat by a solid–liquid
extraction with chloroform after acidification of the sample (pH
3), in order to keep OTA in its neutral form and, thus, soluble in organic
solvent. Then, OTA was extracted from the organic phase by
liquid–liquid partition, using a slightly alkaline buffer solution
(0.2 M Tris–HCl) (pH 8.5). The slightly alkaline pH allowed for
the back-extraction of the dianionic form of OTA, and purification
of the analyte from most of the interferents. The validation parameters
of the method are summarised in Table 1.