Polyether ionophores residues in Minas Frescal cheese by UHPLC-MS/MS

Simultaneous Screening of 172 Veterinary Drugs by Modified QuEChERS-LC-MS/MS in TCM Galli Gigerii Endothelium Corneum

An analytical method was developed for the screening of 172 veterinary drugs in traditional Chinese medicine Galli Gigerii Endothelium Corneum by high-performance liquid chromatography tandem mass spectrometry. The samples were pretreated by a modified QuEChERS method. A Zorbax Eclipse plus C18 column (1.8 μm, 3.0 × 150 mm2, Agilent) was used for the separation of analytes by gradient elution. All analytes were detected by electrospray ionization mass spectrometry with multiple reaction monitoring mode. Good linearity with R ≥ 0.99 was exhibited for all analytes within the respective range. The recoveries of all monitored analytes ranged from 55.4 to 127.6% at three spiked levels (limit of quantitation-LOQ, 2-fold LOQ, 10-fold LOQ), with relative standard deviations <17.8%. The estimated LOQ levels were 0.2-20 μg/kg. The application of this method provides a reference for the safety control of traditional Chinese medicines.

A Review on Pretreatment and Analysis Methods of Polyether Antibiotics in Complex Samples

Polyether antibiotics (PAs) are the anti-coccidiosis drugs used for treating and preventing coccidiosis. Studies show the residues of these antibiotics in food cause adversities and threaten human health. PAs thus need robust, rugged, and accurate methods for their analysis. This review encompasses pretreatment and detection methods of PAs in diverse matrices since 2010. Both conventional and developed methods are part of the pretreatments, such as dispersive liquid-liquid microextraction, solid-phase extraction, solid-phase microextraction, solvent front position extraction, QuEChERS (Quick Easy Cheap Effective Rugged and Safe), supercritical fluid extraction, and others. The analysis methods involve liquid chromatography coupled with detectors, sensors, etc. The pros and cons of various techniques for PAs have been discussed and future tendencies are proposed.

Polyether ionophores residues in pasteurized milk marketed in the state of São Paulo, Brazil: Occurrence and exposure assessment

This paper aimed to survey the occurrence of six polyether ionophores (lasalocid, maduramycin, monensin, narasin, salinomycin and semduramycin) in pasteurized milk using a validated method by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). For that, 40 samples of pasteurized milk, from seven brands, collected in six locations (supermarkets, grocery stores and greengrocers) in the metropolitan region of São Paulo and Campinas, São Paulo State, Brazil, were evaluated. Sampling included whole (18), skimmed (8) and semi-skimmed (10) milk as well as lactose-free (4) products. Only monensin antibiotic residues were found in the analyzed samples. This ionophore was confirmed in 45% of the samples and quantified in 32.5% at concentrations ranging from 0.1 to 0.27 μg kg^-1. The positive samples were whole or semi-skimmed milk. Considering the levels of monensin reported in the present study and data on milk consumption in Brazil, an exposure assessment indicated that the intake of this antibiotic does not represent a risk to health.