Antibiotics are commonly used in the poultry industry to treat bacterial infections. In the combat against bacterial resistance, policies require, besides a reduction of antibiotic usage in humans ...and animals, an up-to-date farmer registration mentioning all treatments. For enforcement of such policies, tests are needed to antedate administration and to determine the type of treatment so as to prevent off-label use and the supervacaneous use of last-resort antibiotics like cephalosporins and fluoroquinolones. After poultry treatment, high amounts of enrofloxacin and its metabolite ciprofloxacin are deposited in chicken feathers. A method is presented to discriminate different treatments based on differentiating extractable and non-extractable enrofloxacin and ciprofloxacin in chicken feathers. With this approach, we show it is possible to distinguish between a registered therapeutic oral treatment, an off-label spray treatment and an illegal prolonged sub-therapeutic treatment with enrofloxacin. This approach is a new and strong tool in the enforcement of new policies in the fight against off-label and supervacaneous antibiotic use. Graphical abstract Therapeutic treatment
In The Netherlands, all antibiotic treatments should be registered at the farm and in a central database. To enforce correct antibiotic use and registration, and to enforce prudent use of ...antibiotics, there is a need for methods that are able to detect antibiotic treatments. Ideally, such a method is able to detect antibiotic applications during the entire lifespan of an animal, including treatments administered during the first days of the animals’ lives. Monitoring tissue, as is common practice, only provides a limited window of opportunity, as residue levels in tissue soon drop below measurable quantities. The analysis of feathers proves to be a promising tool in this respect. Furthermore, a qualitative confirmatory method was developed for the analyses of six major groups of antibiotics in ground chicken feathers, aiming for a detection limit as low as reasonably possible. The method was validated according to Commission Decision 2002/657/EC. All compounds comply with the criteria and, as a matter of fact, 58% of the compounds could also be quantified according to regulations. Additionally, we demonstrated that a less laborious method, in which whole feathers were analyzed, proved successful in the detection of applied antibiotics. Most compounds could be detected at levels of 2 μg kg
−1
or below with the exception of sulfachloropyridazine, tylosin, and tylvalosin. This demonstrates the effectiveness of feather analysis to detect antibiotic use to allow effective enforcement of antibiotic use and prevent the illegal, off-label, and nonregistered use of antibiotics.
The extent of unidentified Per- and Poly-fluoroalkyl substances (PFASs) found in environmental samples has led to the development of non-targeted screening methods. The study presented here reports ...the use of liquid chromatography hyphenated with high resolution mass spectrometry to detect and identify unknown and unexpected PFASs by fragment ion flagging (FIF). By exploring all ion fragmentation spectra for several characteristic fragments including CnF2n+1−, CnF2n-1−, CnF2n-3−, CnF2n-7−, CnF2n-11− and CnF2n+1O− the presence of widely different PFAS species can be anticipated without the need for targeted screening methods. These fragments are then related to their precursor ion by retention time matching and subsequently identified. With this methodology 40 PFASs were (tentatively) identified in four surface water samples sampled throughout the Netherlands. To the best of the authors’ knowledge, four PFASs found through FIF are newly discovered species and have not been mentioned in any database or literature. This methodology eliminates the dependence on commonly reported full scan feature selection techniques such as mass defect filtering, homologous series detection and intensity threshold filtering, allowing the identification of PFASs at trace levels. Additionally, eight of the (tentatively) identified PFASs are not part of homologous series, stressing the shortcomings of commonly reported non-targeted PFASs screening methods and demonstrating the importance of more effective identification strategies such as FIF. Moreover, we like to emphasise that this approach is applicable to real-life environmental samples with PFASs at background concentration levels.
•Novel PFASs were discovered with non-targeted screening using Fragment Ion Flagging.•Fragment Ion Flagging allowed the identification of PFASs at trace levels.•Screening techniques such as homologous series detection proved to be ineffective.•Fragment based mass spectrometry was demonstrated to be an effective alternative.•Novel PFASs were found in environmental samples, i.e. surface water.
The analysis of antibiotics in animal faeces is important to obtain more insight in the possible formation of bacterial resistance in the animals׳ gut, to learn about the dissemination of antibiotics ...to the environment, to monitor trends in antibiotic usage and to detect the illegal and off-label use of antibiotics. To facilitate these studies a comprehensive method for the analysis of trace levels of 44 antibiotic compounds including tetracyclines, quinolones, macrolides and sulfonamides in animal faeces by liquid chromatography in combination with tandem mass spectrometric (LC–MS/MS) detection is reported. The method is fully validated according to European regulation and showed satisfactory quantitative performance according to the stringent criteria adopted, with the exception of some of the macrolide compounds, which can be analysed with somewhat high measurement uncertainty. A large survey was carried out monitoring swine and cattle faeces and the outcomes were striking. In 55% of the swines, originating from 80% of the swine farms and in 75% of the calves, originating from 95% of the cattle farms, antibiotics were detected. Oxytetracycline, doxycycline and sulfadiazine were the most detected antibiotics, followed by tetracycline, flumequine, lincomycin and tylosin. Over 34% of the faeces samples contained two or more different antibiotics with a maximum of eight. Possible explanations for these findings are given and the effects are discussed.
Display omitted
•For the first time a multi-class method for the analysis of over 20 antibiotics in faeces is presented.•The presented method is fully validated according to 2002/657/EC.•A comprehensive survey was carried out in pig and calve production.•A high number of antibiotics were detected in faeces.•In 34% of the samples more than one antibiotic was detected in animal faeces, up to a mixture of eight different compounds.
Per- and polyfluoroalkyl substances (PFASs) are a large and diverse class of chemicals. While some have been phased out internationally due to concerns over their human and environmental health ...risks, novel alternative PFASs continue to be manufactured and detected in environmental samples. The occurrence and fate of these alternatives remain poorly understood. The present study investigated the occurrence of an emerging class of PFAS alternative, the monohydrogen-substituted perfluoroalkyl carboxylic acids (H–PFCAs), in conjunction with the more well-known PFCAs. A weak anion exchange solid phase extraction-liquid chromatography tandem mass spectrometry method for quantitative determination of H–PFCAs in surface water was developed, validated, and applied on samples collected from the Netherlands. To improve chromatography, especially for short-chain (H-)PFCAs, an ion-pairing agent, tetrabutylammonium hydrogen sulphate, was used. The method was validated for linearity (R2 > 0.99), instrumental detection limits (0.01–0.09 ng/mL), method detection limits (0.03–0.75 ng/mL), matrix effects (<20%), percent absolute- and relative recovery (57–121%), trueness (130-80%), repeatability (<20%), and within-lab reproducibility (<20%). Eleven out of fourteen PFASs showed acceptable results. Application of the newly validated method to surface water throughout the Netherlands revealed trace levels of H–PFCAs (including two new H–PFCAs) and high concentrations of PFCAs.
•Hydrogen-substituted perfluoroalkyl carboxylic acids (H–PFCAs) are PFAS alternatives emerging in the environment.•An WCX-SPE-LC-MS/MS method was developed, optimized, and validated, using an ion-pairing agent.•Quantification; After application on surface water, H–PFCAs were found in trace levels and PFCAs in high concentration.
We developed a procedure to determine the “identification power” of an LC-MS/MS method operated in the MRM acquisition mode, which is related to its selectivity. The probability of any compound ...showing the same precursor ion, product ions, and retention time as the compound of interest is used as a measure of selectivity. This is calculated based upon empirical models constructed from three very large compound databases. Based upon the final probability estimation, additional measures to assure unambiguous identification can be taken, like the selection of different or additional product ions. The reported procedure in combination with criteria for relative ion abundances results in a powerful technique to determine the (un)certainty of the selectivity of any LC-MS/MS analysis and thus the risk of false positive results. Furthermore, the procedure is very useful as a tool to validate method selectivity.
Figure
According to EU legislation a confirmatory method used for residue analysis should be able to confirm the identity of a compound beyond reasonable doubt. To provide an adequate instrumental set-up, ...Commission Decision 2002/657/EC introduced the concept of “identification points”. A second aspect to assure unequivocal confirmation, is the establishment of ion ratio and retention time criteria. Currently, the gold standard for confirmatory analysis of most veterinary drug residues is liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) in selected reaction monitoring (SRM) acquisition mode, isolating one precursor ion and monitoring two a priori selected product ions, yielding 4 identification points. We comprehensively evaluated the use of different low and high resolution LC-MS(/MS) techniques and acquisition modes with respect to the selectivity of 100 veterinary drugs in liver, muscle and urine extracts aiming to critically review the currently established identification points system. A comparison among MS/MS in SRM mode with high resolution mass spectrometry (HRMS) in full scan, all ion fragmentation and targeted MS/MS was made based on a unique inter-laboratory study, which comprises 21 laboratories from four different continents and equipment from all major vendors.
In total 186 samples were analysed yielding results for 9282 analyte/matrix combinations. It was observed that the false positive rate approximately doubles if no ion ratio criterion is applied indicating that this criterion is important to prevent false positive results. Full scan HRMS analysis, only monitoring the molecular ion and allowing a ±5 ppm mass tolerance is, in general, less selective than low resolution MS/MS using SRM, and thus full scan alone is considered not sufficient for confirmatory analysis. Furthermore, even though the number of data on all ion fragmentation and targeted MS/MS at high resolution was limited, based on the data obtained, it was observed that the acquisition mode as well as the mass resolution needed, very much depend on the matrix and the compound itself. For complex matrix extracts and non-selective compounds (worst-case situation), only targeted MS/MS, monitoring the precursor ion and a single product ion in HR-MS using a maximum of ±5 ppm mass deviation, leads to comparable selectivity and false positive and negative rate as SRM monitoring two product ions in LR-MS. We conclude that the currently applied identification point system as established in commission decision 2002/657/EC should be revised with respect to the allocation of identification points.
Display omitted
•For the first time a global inter-laboratory study was carried out.•Collaboration among 21 laboratories from 4 continents.•Unique data set on basis of which several common and new techniques/acquisition modes are assessed.•Proposal for revision of the identification point system of EC 2002/657/EC.
Through agricultural soil fertilization using organic manure, antibiotic residues can accumulate in the environment. In order to assess the risks of environmental pollution by veterinary drugs, ...monitoring of manure for antibiotic residues is necessary. As manure is a complex matrix, extraction of antibiotics proved to be challenging. In this study, 24 extraction solvents were assessed for the extraction of residues from manure representing ten antibiotics from the antibiotic classes tetracyclines, quinolones, macrolides, lincosamides and sulfonamides. Especially for the tetracyclines and quinolones the extraction solvent selection is critical, due to high fractions of non-extractable residues especially when using aqueous solvents (62–77% and 90–95% respectively when using milli-Q water). In contrast, sulfonamides can effectively be extracted with aqueous solvents. Overall, 0.125% trifluoroacetic acid in acetonitrile in combination with McIlvain-EDTA buffer proved to be the most effective extraction solvent. A longitudinal study pointed out that most antibiotics bind to solid manure particles instantaneously after addition. Trimethoprim is an exception, but because by using the optimal extraction solvent, the optimum fraction of bound residues is desorbed, this does not hamper quantitative analysis when using spiked manure quality control samples. Based on these new insights, the current in-house multi-residue LC-MS/MS method for manure analysis, containing 48 antibiotics, was revised, additionally validated and applied to 34 incurred manure samples.
Display omitted
•The amount of non-extractable residues of 10 antibiotics was determined in manure using 24 different extraction solvents.•Results of a longitudinal study to further investigate the fate of non-extractable residues over time is reported.•An optimized method, validated for the analysis of 48 antibiotics in manure is presented.•This data contributes to the understanding of the processes during extraction of manure.
A liquid chromatography–tandem mass spectrometry method for the analysis of seven antiviral drugs, zanamivir, ribavirin, oseltamivir, oseltamivir carboxylate, amantadine, rimantadine and arbidol, in ...poultry muscle is reported. The antiviral drugs were extracted from the homogenized poultry muscle sample using methanol. The extract was purified using tandem solid-phase extraction combining a cation exchange cartridge and a phenylboronic acid cartridge. To prevent excessive matrix effects, the analytes were separated from the matrix constituents using a column-switch liquid chromatography system combining a reversed-phase and a Hypercarb analytical column. Detection was carried out using tandem mass spectrometry. The method was fully validated according to 2002/657/EC
1
and proved to be adequate for quantification and confirmation of zanamivir and ribavirin at 10 μg kg
−1
, oseltamivir, oseltamivir carboxylate, amantadine and rimantadine at levels below 1.0 μg kg
−1
and for qualitative confirmatory analysis of arbidol at levels below 1 μg kg
−1
.
Paper spray tandem mass spectrometry is used to identify and quantify eight individual amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic ...toxicology guidelines, for the quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-
N
-methylamphetamine (MDMA), 3,4-methylenedioxy-
N
-ethylamphetamine (MDEA),
para
-methoxyamphetamine (PMA),
para
-methoxymethamphetamine (PMMA), and 4-fluoroamphetamine (4-FA). Additionally, a new concept of intrinsic and application-based selectivity is discussed, featuring increased confidence in the power to discriminate the amphetamines from other chemically similar compounds when applying an ambient mass spectrometric method without chromatographic separation. Accuracy was within ±15% and average precision was better than 15%, and better than 20% at the LLOQ. Detection limits between 15 and 50 ng/mL were obtained using only 12 μL of whole blood.
Graphical abstract
ᅟ
PDF
