Anthelmintic drug residues quantification from green edible beef offal (tripe) using the liquid chromatography/mass spectrometry (LC–MS/MS)

Abstract Anthelmintics are medications used to treat parasitic infections in aquaculture, agriculture, and, occasionally, in humans. These drugs target a range of parasites, including worms, trematodes, nematodes, and cestodes. The objective of this study was to determine the levels of anthelmintic residues in tripe samples collected from abattoirs and butcheries in Gaborone, Botswana, using the LC–MS/MS analytical technique. This investigation was prompted by a local knowledge gap regarding the presence of anthelmintic residues in edible beef offal because with inadequate veterinary procedures, there may be drug residue above the MRL which could have a negative impact on human health. A total of 30 tripe samples were collected, 12 from abattoirs and 18 from butcheries, and tested for the presence of 24 different anthelmintic compounds. Most samples showed little to no detectable residues. However, two samples out of 30, S1 and S4, tested positive for levamisole, with concentrations of 102.5 μg/kg and 28.3 μg/kg, respectively. These levels exceeded the EU maximum residue limit (MRL) permitted for food products in Botswana. Based on these findings, it is recommended that longer withdrawal periods be observed following the administration of levamisole to livestock as part of the monitoring protocols. Additionally, minimizing the use of this drug and opting for safer alternative treatments can contribute to producing safer offal and promoting better public health.