Fit-for-purpose in veterinary drug residue analysis: Development and validation of an LC-MS/MS method for the screening of thirty illicit drugs in bovine urine

Development of a rapid-fire drug screening method by probe electrospray ionization tandem mass spectrometry for human urine (RaDPi-U)

Drug screening tests are mandatory in the search for drugs in forensic biological samples, and immunological methods and mass spectrometry (e.g., gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry) are commonly used for that purpose. However, these methods have some drawbacks, and developing new screening methods is required. In this study, we develop a rapid-fire drug screening method by probe electrospray ionization tandem mass spectrometry (PESI-MS/MS), which is an ambient ionization mass spectrometry method, for human urine, named RaDPi-U. RaDPi-U is carried out in three steps: (1) mixing urine with internal standard (IS) solution and ethanol, followed by vortexing; (2) pipetting the mixture onto a sample plate for PESI; and (3) rapid-fire analysis by PESI-MS/MS. RaDPi-U targets 40 forensically important drugs, which include illegal drugs, hypnotics, and psychoactive substances. The analytical results were obtained within 3 min because of the above-mentioned simple workflow of RaDPi-U. The calibration curves of each analyte were constructed using the IS method, and they were quantitatively valid, resulting in good linearity (0.972-0.999) with a satisfactory lower limit of detection and lower limit of quantitation (0.01-7.1 ng/mL and 0.02-21 ng/mL, respectively). Further, both trueness and precisions were 28% or less, demonstrating the high reliability and repeatability of the method. Finally, we applied RaDPi-U to three postmortem urine specimens and successfully detected different drugs in each urine sample. The practicality of the method is proven, and RaDPi-U will be a strong tool as a rapid-fire drug screening method not only in forensic toxicology but also in clinical toxicology.

Multiresidue Determination of Growth Promoters in Bovine Serum using QuEChERS and UHPLC-Q-ORBITRAP: Validation and In Vivo Study

A reliable method using a QuEChERS approach and liquid chromatography coupled to Q-Orbitrap mass spectrometry was optimized and validated for the quantification of 20 growth promoters in bovine serum. The recoveries ranged from 91.4-114.1%, relative standard deviations varied between 0.3-4.0%, and CCα values were between 0.023-0.350 μg L-1. The developed method was applied in an in vivo study using steers, which were intramuscularly treated with commercial injections containing stanozolol. A rapid metabolization was observed, with a detection window ranging from 3 to 10 days. The stability of incurred stanozolol was confirmed after 240 days at -20 °C and also after 5 freeze-thaw cycles. To the best of our knowledge, this is the first work in which an in vivo study was performed to support the monitoring of stanozolol in bovine serum. In addition, the use of Q-Orbitrap high-resolution mass spectrometry allows for retrospective analysis from a surveillance perspective.

Establishment of pressurized liquid extraction followed by HPLC-MS/MS method for the screening of adrenergic drugs, steroids, sedatives, colorants and antioxidants in swine feed

A facile and sensitive multi-residue detection approach of pressurized liquid extraction following high-performance liquid chromatography tandem mass spectrometry was established to detect the residues of adrenergic drugs, steroids, sedative, colorant and antioxidant in feed. The conditions employed for pressurized liquid extraction involved acetonitrile/ethyl acetate (1:1, v/v) as the extracting solvent, the temperature 80°C, two cycles and a static time of 10 min. The extraction was followed by a solid-phase extraction clean-up step. The separation of samples was done by C₁₈ column with the mobile phase of 5 mM ammonium acetate solution and acetonitrile with 0.1% formic acid. The limits of quantification ranged from 0.03 to 1 μg/kg, limits of detection were in a range of 0.01-0.5 μg/kg, and average recoveries were 70.4-98.6%. The pressurized liquid extraction procedure was optimized and overall method was validated in terms of sensitivity, linearity, selectivity, matrix effect, accuracy, recovery and stability of the target drugs in the pressurized liquid extraction extracts solution. The screening method was proved to be fast, selective, accurate and sensitive for screening drugs.

Development and validation of an UHPLC-MS/MS method for β2-agonists quantification in human urine and application to clinical samples

A fast analytical method for the simultaneous detection of 24 β₂-agonists in human urine was developed and validated. The method covers the therapeutic drugs most commonly administered, but also potentially abused β₂-agonists. The procedure is based on enzymatic deconjugation with β-glucuronidase followed by SPE clean up using mixed-phase cartridges with both ion-exchange and lipophilic properties. Instrumental analysis conducted by UHPLC-MS/MS allowed high peak resolution and rapid chromatographic separation, with reduced time and costs. The method was fully validated according ISO 17025:2005 principles. The following parameters were determined for each analyte: specificity, selectivity, linearity, limit of detection, limit of quantification, precision, accuracy, matrix effect, recovery and carry-over. The method was tested on real samples obtained from patients subjected to clinical treatment under chronic or acute therapy with either formoterol, indacaterol, salbutamol, or salmeterol. The drugs were administered using pressurized metered dose inhalers. All β₂-agonists administered to the patients were detected in the real samples. The method proved adequate to accurately measure the concentration of these analytes in the real samples. The observed analytical data are discussed with reference to the administered dose and the duration of the therapy.

High throughput-screening of animal urine samples: It is fast but is it also reliable?

Advanced analytical technologies like ultra-high-performance liquid chromatography coupled to high resolution mass spectrometry can be used for veterinary drug screening of animal urine. The technique is sufficiently robust and reliable to detect veterinary drugs in urine samples of animals where the maximum residue limit of these compounds in organs like muscle, kidney, or liver has been exceeded. The limitations and possibilities of the technique are discussed. The most critical point is the variability of the drug concentration ratio between the tissue and urine. Ways to manage the false positive and false negatives are discussed. The capability to confirm findings and the possibility of semi-targeted analysis are also addressed. Copyright © 2016 John Wiley & Sons, Ltd.

Multiclass method for the quantification of 92 veterinary antimicrobial drugs in livestock excreta, wastewater, and surface water by liquid chromatography with tandem mass spectrometry

A simple multiresidue method was developed for detecting and quantifying 92 veterinary antimicrobial drugs from eight classes (β-lactams, quinolones, sulfonamides, tetracyclines, lincomycins, macrolides, chloramphenicols, and pleuromutilin) in livestock excreta and water by liquid chromatography with tandem mass spectrometry. The feces samples were extracted by ultrasound-assisted extraction with a mixture of acetonitrile/water (80:20, v/v) and edetate disodium, followed by a cleanup using solid-phase extraction with an amino cartridge. Water samples were purified with hydrophilic-lipophilic balance solid-phase extraction column. Urine samples were extracted with acetonitrile and edetate disodium. Detection of veterinary antimicrobial drugs was achieved by liquid chromatography with tandem mass spectrometry using both positive and negative electrospray ionization mode. The recovery values of veterinary antimicrobial drugs in feces, urine, and water samples were 75-99, 85-110, and 85-101% and associated relative standard deviations were less than 15, 10, and 8%, respectively. The limits of quantification in feces, urine, and water samples were 0.5-1, 0.5-1, and 0.01-0.05 μg/L, respectively. This method was applied to determine real samples obtained from local farms and provides reliable quantification and identification results of 92 veterinary antimicrobial drugs in livestock excreta and water.

Evaluation of nandrolone and ractopamine in the urine of veal calves: liquid chromatography-tandem mass spectrometry approach

Under European legislation, the use of growth promoters is forbidden in food-producing livestock. The application of unofficial protocols with diverse combinations of veterinary drugs, administered in very low concentrations, hinders reliable detection and subsequent operative prevention. It was observed that nandrolone (anabolic steroid) and ractopamine (β-adrenergic agonist) are occasionally administered to animals, but little is known about their synergic action when they are administered together. Two specific analytical methods based on liquid chromatography-tandem mass spectrometry have been developed, both of which include hydrolysis of the corresponding conjugates. For the nandrolone method, solid-phase extraction was necessary for the complete elimination of the interferences, while employment of the Quantitation Enhanced Data-Dependent scan mode during MS acquisition of ractopamine enabled the utilization of simple liquid-liquid extraction. The nandrolone method was linear in the range of 0.5-25 ng/mL, while the ractopamine calibration curve was constructed from 0.5 to 1000 ng/mL. The corresponding coefficients of correlations were >0.9907. The lower limit of quantification for both methods was 0.5 ng/mL, followed by overall recoveries >81%. Precisions expressed as relative standard deviations were <17%, while matrix effects were minimal. Urine samples taken at the slaughterhouse from veal calves enrolled in an experimental treatment consisting of intramuscular administration of β-nandrolone-phenylpropionate accompanied with a ractopamine-enriched diet were analysed. Those methods might be useful for studying the elimination patterns of the administered compounds along with characterization of the main metabolic pathways. Copyright © 2016 John Wiley & Sons, Ltd.

Development of an ultra high performance liquid chromatography method for determining triamcinolone acetonide in hydrogels using the design of experiments/design space strategy in combination with process capability index

An ultra high performance liquid chromatography method was developed and validated for the quantitation of triamcinolone acetonide in an injectable ophthalmic hydrogel to determine the contribution of analytical method error in the content uniformity measurement. During the development phase, the design of experiments/design space strategy was used. For this, the free R-program was used as a commercial software alternative, a fast efficient tool for data analysis. The process capability index was used to find the permitted level of variation for each factor and to define the design space. All these aspects were analyzed and discussed under different experimental conditions by the Monte Carlo simulation method. Second, a pre-study validation procedure was performed in accordance with the International Conference on Harmonization guidelines. The validated method was applied for the determination of uniformity of dosage units and the reasons for variability (inhomogeneity and the analytical method error) were analyzed based on the overall uncertainty.

Development, validation and application to real samples of a multiresidue LC-MS/MS method for determination of β2 -agonists and anabolic steroids in bovine hair

β(2) -agonists are often abused in cattle breeding because of their effects on animal growth and meat properties. The use of β(2) -agonists as growth promoters is forbidden in the European Union (Council Directive 96/23/EC classifies them into group A of Annex I), due to their toxicity and carcinogenic properties, as for anabolic steroids, which are often administered in combination with β(2) -agonists, to promote the storage of proteins and increase muscle size. A unique confirmatory liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitative detection of 13 β(2) -agonists and anabolic steroids plus the qualitative identification of other three analytes in bovine hair was developed and validated, according to Decision 2002/657/CE. Hair samples were washed with dichloromethane, digested within a NaOH solution and subjected to liquid-liquid extraction. The analysis was performed by high performance liquid chromatography coupled to a triple quadrupole mass spectrometer operating in the selected reaction monitoring mode. The absence of matrix interferents, together with good repeatability of both retention times and relative abundances of diagnostic transitions, allowed the correct identification of all analytes. The quantitative calibrations obtained from spiked blank hair samples proved linear in the range tested. CCα and CCβ ranged from 0.5 ng/g to 30 ng/g. Intralaboratory reproducibility (CV%) ranged between 5.0 and 17.7 and trueness between 96% ± 7% and 105% ± 8%. The applicability of the method to real positive samples was demonstrated for both β(2) -agonists and anabolic steroids. 17α-boldenone was found in most (70%) hair samples obtained from untreated animals, supporting the hypothesis of endogenous production of this steroid.

Analytical investigations about the presence of prednisolone in cow urine

Since 2008, the analyses carried out in the Lombardia region as part of National Residue Control Plans have evidenced unexpected frequent detection of the corticosteroid prednisolone (PRED) in cow urine samples taken to the slaughterhouse. Considering the scarce plausibility of these high frequent findings, analytical investigations were started to ascertain the real presence of this corticosteroid. The applied confirmatory method involved liquid-chromatography low-resolution tandem mass spectrometry (triple quadrupole) as instrumental technique, and it was validated in compliance with the requirements of the Commission Decision 2002/657/EC. However, recently some criticism regarding Commission Decision 2002/657/EC identification criteria has been pointed out, experimentally demonstrating false positive results (wrong identification) although these criteria have been strictly observed. Therefore, considering the serious implications (i.e. the possibility that PRED could be considered endogenous in particular animal conditions), studies were carried out to investigate the reliability of PRED identification through the change of the chromatographic conditions (mobile phases, gradient and analytical column) of the confirmatory procedure routinely applied. Further confirmation came from the application of high-resolution mass spectrometry technique (MS(2) and MS(3) experiments) to analyze incurred cow urines samples. All the obtained results confirmed definitively the real presence of this corticosteroid excluding false-positive findings in routine analysis. In addition, other experiments demonstrated that high-resolution mass spectrometers (Time of Flight and Orbitrap technologies) could be successfully applied to routine determination of steroid residues in biological fluids at very low concentrations (< 1 µg L(-1)).

Wide-range screening of banned veterinary drugs in urine by ultra high liquid chromatography coupled to high-resolution mass spectrometry

In this work, an ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology is proposed for the multi-class multi-residue screening of banned and unauthorized veterinary drugs in bovine urine, using an Orbitrap Exactive™ analyzer working at a resolving power of 50,000 FWHM in full scan, both in positive and negative mode. The method currently covers 87 analytes belonging to different families such as steroid hormones, β-agonists, resorcylic acid lactones (RAL), stilbens, tranquillizers, nitroimidazoles, corticosteroids, NSAIDs, amphenicoles, thyreostatics and other substances such as dapsone. A database including the elemental composition, the polarity of acquisition, retention time and expected adducts was built for the targeted analysis, and a high mass accuracy (<5 ppm) was set as one of the identification criteria. After comparing different sample preparation procedures, QuEChERS was selected as the most appropriate methodology. An efficient separation of analytes was achieved using ultra high performance liquid chromatography with a column packed with sub-2 μm particles. The performance of the method has been evaluated in accordance with the EU guidelines for the validation of screening methods for the analysis of veterinary drugs residues. The screening target concentrations were established between 0.2 μg/l and 20 μg/l, demonstrating the usefulness of UHPLC-HRMS as an ideal tool for compliance monitoring in regulatory laboratories.