Comparison of different sample treatments for the analysis of ochratoxin A in wine by capillary HPLC with laser-induced fluorescence detection.

Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.
Analytical and Bioanalytical Chemistry (Impact Factor: 3.66). 09/2011; 401(9):2987-94. DOI: 10.1007/s00216-011-5387-3
Source: PubMed

ABSTRACT Ochratoxin A (OTA) is a mycotoxin naturally found in various foods, including wine. As OTA is considered as a possible human carcinogen, the maximum concentration for this compound has been established at 2 μg kg(-1) in wine by the EU (Directive (CE) No 1881/2006). Typically, immunoaffinity columns have been used for its extraction. However, simpler, more efficient and less contaminant extraction systems are demanding. In this work, dispersive liquid-liquid microextraction using ionic liquid as extractant solvent (IL-DLLME) and the QuEChERS procedure, have been evaluated and compared for extraction of OTA in wine samples. Laser-induced fluorescence (LIF, He-Cd Laser excitation at 325 nm) coupled with capillary HPLC has been used for the determination of OTA, using a sodium dodecyl sulfate micellar solution in the mobile phase to increase the fluorescence intensity. Matrix-matched calibration curves were established for both methods, obtaining LODs (3× S/N) of 5.2 ng·L(-1) and 85.7 ng·L(-1) for IL-DLLME and QuEChERS, respectively. Clean extracts were obtained for white, rose and red wines with both methods, with recoveries between 88.7-94.2% for IL-DLLME and between 82.6-86.2% for QuEChERS. The precision was evaluated in terms of repeatability (n = 9) and intermediate precision (n = 15), being ≤ 8.5% for IL-DLLME and ≤ 5.4% for QuEChERS.

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