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Milk is one of the most widely consumed foods in the world, despite the increasing consumption of plant-based alternatives. Although rich in nutrients and believed by consumers to be free of undesirable contaminants, milk, whether of animal or plant origin, is not always free from residues of chemical substances, including veterinary medicines. For instance, in intensive livestock production, antibiotics are often used to treat animals or, illicitly, to improve their growth performance, which can lead to their presence in the final food. Additionally, the continuous use of veterinary drugs in intensive animal production can lead to their occurrence in agricultural soils and therefore are absorbed by plants as another source of entering the food chain. An effective and accurate multi-detection quantitative screening method to analyze 89 antibiotics in milk was optimized by ultra-high-performance liquid chromatography coupled with a time-of-flight detector (UHPLC-ToF-MS) and further validated in accordance with the Commission Implementing Regulation (CIR) 808/2021 and the International Council for Harmonization (ICH) guidelines on the validation of analytical procedures. Apart from the specific parameters required by CIR 808/2021, the aim was to access the lower limits of the method, limits of detection (LoD) and quantification (LoQ), regardless of the maximum residue limits (MRLs) defined in the legislation. The method was then applied in the analysis of 32 supermarket samples, resulting in four positive findings, including one plant-based sample. The antibiotics found were from the macrolides and sulphonamides families. Nevertheless, the concentrations detected were below the established maximum residue level (MRL). [ABSTRACT FROM AUTHOR]

Anthropogenic chemical contamination represents a key stressor of natural environments with pharmaceuticals comprising a particular group of emerging pollutants with the potential to induce biological responses in non-target organisms. Therefore, an analytical method based on ultra-high-performance liquid chromatography coupled to time-of-flight tandem mass spectrometry (UHPLC-TOF-MS) was developed for estuarine and seawaters, targeting 63 globally used pharmaceuticals (including amoxicillin, ciprofloxacin, sulfamethoxazole, trimethoprim and venlafaxine included in the Surface Water Watch List) from 8 therapeutic groups: antibiotics, analgesic, NSAIDs, antidepressants, β-blockers, lipid regulators, anticonvulsants and antihypertensive drugs. The method presents high selectivity and sensitivity, with the limits of detection ranging from 0.01 to 8.92 ng/L and the limits of quantification from 0.02 to 29.73 ng/L. Considering precision, the highest value was achieved for amoxicillin (20.9%) and the lower for ofloxacin (2.6%), while recoveries ranged from 80.6 to 112.6%. Overall, the quantification method was highly efficient for multi-residues quantification in such complex environmental samples. [ABSTRACT FROM AUTHOR]

The combination of ultra-high-performance liquid chromatography (UHPLC) with time-of-flight mass spectrometry (ToF-MS) is one of the most powerful analytical tools in terms of selectivity, sensitivity and speed. However, due to the gap on regulation and guidelines concerning the validation criteria for the use of ToF-MS methodology not only for screening but also for confirmatory and quantification purposes, this study presents, for the first time, an approach on how to use the referred methodology for confirmatory and quantification purposes. Thus, an UHPLC-ToF-MS method was developed and validated for the simultaneous determination of 43 antibiotic residues from 7 different families (tetracyclines, sulfonamides, quinolones, penicillins, macrolides, cephalosporins and trimethoprim) in piglet kidneys as a confirmatory method. A simple sample preparation consisting of extraction with a mixture of acetonitrile and ethylenediaminetetraacetic acid (EDTA) followed by solid-phase extraction (SPE) with a hydrophilic-lipophilic balanced (HLB) cartridge and finalized with a defatting step with n-hexane was used. The methodology was validated according the Commission Decision 2002/657/EC, by defining suitable criteria for antibiotic identification, as well as by evaluating required parameters like selectivity, specificity and ruggedness that fulfil the required criteria. The calculated values of decision limit (CCα) and of detection capacity (CCβ) for antibiotics with established maximum residue limits (MRLs) fully complied with required criteria. For antibiotics for which no MRL was set, values ranging from 0.2 to 0.5 μg kg−1 and from 0.5 to 0.8 μg kg−1 were achieved for CCα and for CCβ, respectively. Linearity (all R2 > 0.95), recovery (81.4–110.0%) (lowest values of 4.6% and 7.1% were obtained for repeatability and for reproducibility, respectively), LODs (0.04–13.0 μg kg−1), LOQs (0.09–32.0 μg kg−1) and matrix effects (35.5–118.1 %) were also evaluated. After validation, the method was applied to analyse piglet kidney samples. Antibiotic residues were determined in 10 of the 15 analysed samples. However, all the antibiotics concentrations were below the MRLs. [ABSTRACT FROM AUTHOR]