Quantifying Ochratoxin A by U-HPLC

OTA was quantified following the methodology described by Vecchio et al. (2012) [59 (link)]. Determinations were performed by ultra-high performance liquid chromatography (U-HPLC) (Agilent 1290 Infinity II, Santa Clara, CA, USA), equipped with a 20 μL loop and connected to a spectrofluorometer detector, Perkin Elmer Fluorescence Detector Series 200. The excitation and emission wavelengths were 330 and 460 nm. Chromatography was carried out isocratically using 4 mM sodium acetate/acetic acid (19:1): acetonitrile (60:40) as the mobile phase at a 1.0 mL/min flow rate. The working standard solution and sample volumes of 20 μL were injected in triplicate. The parameters were validated by six replicates. The LOD was 1.60 × 10⁻⁵ mg/kg, the LOQ was 4.80 × 10⁻⁵ mg/kg and the linearity coefficient (R²) was 9.997 × 10⁻¹. The retention time was 9.09 ± 0.08 min.