Development and validation of a cyclodextrin-based supramolecular HPLC-fluorescence detection method for determining thiabendazole in camel milk from the United Arab Emirates: A comparative study of extraction techniques

The camel milk industry, increasing over the past decade, has relied on the use of veterinary drugs to maintain safety from parasites. There have been concerns about the levels of thiabendazole, a drug commonly used in camel milk farms, which has been reviewed by the European Commission to set a safe maximum residue limit. This study aims to quantify thiabendazole (TBZ) levels in camel milk samples (in parts per billion) using an HPLC with fluorescence detection (FLD) method with the standard addition calibration technique. Two extraction methods, liquid-liquid extraction and QuEChERS (quick, easy, cheap, effective, rugged, and safe), were able to extract TBZ from complex milk samples with high recovery. An actual concentration as low as 31 ± 6.06 µg/kg was achieved using the HPLC-FLD method developed in this study. An audit of the variance by replicating the experiment within a single day yielded an acceptable relative standard deviation (RSD) of 10.23% and a pooled RSD of 10.281%. Repeatability over a couple of nonconsecutive days resulted in RSD of 10.18%. The method limit of detection was experimentally found to be 30.389 µg/kg, and the limit of quantification was 65.205 µg/kg. The TBZ levels in the randomly selected samples indicate safe consumption of United Arab Emirates camel milk products with regard to TBZ.