Antibiotics and drugs: residue determination

Veterinary drugs pose a real risk to human health if their residues are allowed to enter the food chain. Parent drugs and their metabolites can occur in foodstuffs individually or as multicomponent mixtures with enhanced adverse effects. In order to protect the safety of the consumers, the European Union has established lists of forbidden substances, maximum residue limits for authorized drugs, and precise criteria to perform confirmation and screening analyses and to interpret the related results. This article deals with procedures and techniques applied to monitor pharmaceutical products of major concern, discussing advancements in the past 3 years and the future trends in the food safety field. © 2016 Elsevier Ltd. All rights reserved

A ‘Dilute and Shoot’ Liquid Chromatography-Mass Spectrometry Method for Multiclass Drug Analysis in Pre-Cut Dried Blood Spots

Drugs able to affect the auditory and nervous systems and consumed by workers to treatdifferent pathologies can represent a possible source of risk in the work environment. All the target compounds involved in the presented project show ototoxic and/or narcoleptic side effects and, for these reasons, occupational safety organizations have recognized them as potential causes of work injuries. A multiclass method for the analysis of 15 drugs among the most widespread worldwide (belonging to nine different classes including antihistamines, beta-blockers, antidepressants, Z-drugs and opioids), was developed and validated. This study describes a rapid, sensitive and effective method to analyse these substances in whole blood using tailored pre-cut dried blood spots. Detection was achieved with a triple quadrupole mass spectrometer after an easy and simple ‘dilute and shoot’ solubilisation followed by an UPLC separation. All the issues linked to the use of the dried blood spots and whole blood, such as haematocrit variability, volumetric evaluation and sample carrier choice were carefully studied and managed during method development. From the validation study results it emerged that this approach can be deemed successful thanks to its few pg L1 LOQs, good linear intervals, absolute recoveries of no less than 75%, an almost negligible matrix effect and accuracy and precision in line with the European and American guidelines for validation. All the obtained goals have been specifically pursued in order to encourage method diffusion as a primary prevention intervention, even in small private workplaces

Veterinary drugs residues: a review of the latest analytical research on sample preparation and LC-MS based methods

The world population is increasing and there is a growing demand for food, leading to intensification of farming methods and a requirement for more coadjuvants. Potential high profits sometimes lead to fraudulent use of drugs and pesticides. Veterinary drugs in particular can pose a real risk to human health if their residues are allowed to enter the food chain. Parent drugs and their metabolites can occur in foodstuffs individually or as multicomponent mixtures with enhanced adverse effects. In order to protect consumer safety, the European Union has established lists of forbidden substances, maximum residue limits for authorised drugs and precise criteria for confirmation analyses and interpretation of the results. Due to their nature and potential danger, the ‘best available technique’ should always be applied. Following this principle, this review examines the procedures and techniques applied to monitoring pharmaceutical products of major concern (e.g. anthelmintics, NSAIDs, corticosteroids, coccidiostats) in foods of animal origin, discussing advances over the past five years and future trends in the field of food safety. Our goal was both to focus attention on this important topic and to provide a selection of the most relevant recent papers on drug residues in foodstuffs. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Environmental and biological monitoring of workers exposed to antineoplastic drugs. Dose and effect biomarkers

Antineoplastic drugs are among the most widespread drugs. Consequently, workers involved in their handling and management could be exposed to hazardous chemicals. However, even if procedures are established, it is of the utmost importance that attention on this issue never faint. For these reasons, our Institution is always very attentive and has conducted a specific study in collaboration with “Sapienza”, Rome University. An environmental monitoring campaign, combined with biological monitoring, was carried out in an oncology ward of a hospital in central Italy. Cyclophosphamide, ifosfamide, cytarabine, dacarbazine, doxo and epirubicine, gemcitabine, methotrexate and 5‑fluorouracile were selected for this study due to their diffusion. A wipe‑sampling procedure followed by a LC‑MS/MS analysis was used to evaluate the contamination of benches, hood and general surfaces inside the “Unit for cytotoxic drug preparations” (Unità Farmaci Antiblastici‑UFA). A Solid Phase Extraction procedure coupled with the same LC‑MS/MS method was applied to analyze urine samples of the workers involved in cytotoxic drugs handling. Moreover, biomarkers of oxidative stress were analyzed on the same biological samples in order to evaluate if a correlation exists between drugs exposure and damages to proteins, RNA and DNA. Results showed the presence of one or more of the selected analytes on the surfaces before the cleaning procedure but, worryingly, also after it. Biological monitoring followed a similar trend showing the presence of cyclophosphamide, dacarbazine, methotrexate, cytarabine and 5‑fluorouracile in different samples. Urinary concentration of 8‑oxo‑7,8‑dihydro‑2’‑deoxyguanosine was found higher than that of a group of healthy volunteers not exposed to antineoplastic drugs, showing a possible effect of cytarabine on biomarkers of DNA oxidative stress. Outcomes raised from the analyzed samples and the biomarkers evaluation highlighted the presence of many critical issues. Contamination depends on many factors, such as working modalities and cleaning procedures, however specific training courses as well as continuous monitoring plans for risk assessment are still extremely important to protect the workers’ health

Simultaneous determination of the urinary metabolites of benzene, toluene, xylene and styrene using high-performance liquid chromatography/hybrid quadrupole time-of-flight mass spectrometry

A simple and rapid method using reversed-phase liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the simultaneous determination of the urinary metabolites of benzene, toluene, xylene and styrene in human urine specimens and standard solutions is described. A hybrid quadrupole/time-of-flight (QqTOF) mass spectrometer was compared for the determination of metabolite of aromatic solvents in urine samples. The metabolites selected were: trans, trans-muconic acid, hippuric acid, o-, m- and p-methylhippuric acid and phenylglyoxylic acid. The compounds were well separated from each other on narrow-bore 1-mm i.d. reversed-phase LC C-18 columns. Average recoveries for loading 100 muL of urine samples varied from 88-110% and the quantification limits were less than 30 ng/mL for each analyte (3 ng/mL for trans,transmuconic acid). The qualitative information obtained (mass accuracy, resolution and full-scan spectra) with the QqTOF mass spectrometer allows a secure identification of analytes in biological matrices. Copyright (C) 2004 John Wiley Sons, Ltd

Recent advancements and future trends in environmental analysis: sample preparation, liquid chromatography and mass spectrometry

Among the thousands of chemicals having potential to enter the environment, the NORMAN network has identified at least 700 substances categorized into 20 classes in the European surface waters. Pesticides, pharmaceuticals, disinfection by-products, wood preservation and industrial chemicals are the prominent classes. Since the impact of these substances on aquatic life and human health might be dramatic, action is urgently required at multiple levels; one of them is just related to the development of more and more sensible and selective analytical methods. This review highlights the latest advancements and trends in liquid chromatographye-mass spectrometry based environmental analysis. Specific sections are dedicated to novelties in sample preparation, chromatographic separation and mass spectrometry detection of emerging pollutants. The review also offers insights on last generation chromatographic and extraction materials, technological progresses and innovative methodological approaches for target and non-target analysis. As numerous papers have been published in this field, this overview covers the most representative and original works published in the 2011-2016 period. (C) 2017 Elsevier B.V. All rights reserved

Simultaneous Determination of Type A, B and D Trichothecenes in Maize Products by HPLC-ESI-MS/MS

Trichothecenes, the largest group of Fusarium mycotoxins, constitute the main natural contaminants of cereals in the temperate regions of America, Asia and Europe. They act at biochemical and cellular level, exhibiting acute, chronic, mutagen and teratogen toxicity in humans and animals. Trichothecenes are polycyclic sesquiterpenoids characterized by a C9-C10 double bond, by a variable number of hydroxyl and acetoxy groups and by a C12-C13 epoxide ring. Depending on their functional groups, they have been classified in four groups, named A, B, C and D1,2. Within the European Union, an opinion on the Fusarium toxins was expressed by the Scientific Committee for Food since 19993,4 and by means of the Commission Regulation 2005/856/CE5, modifying previous one 2001/466/CE, were established new Daily Acceptable Intake (ADI) for the most dangerous Fusarium toxins, but none maximum residue limit (MRL) for the trichothecenes except the most frequently occurring deoxynivalenol; before 1st July 2007 a tolerance level will be fixed also for T-2 and HT-2. A new method of analysis, based on liquid chromatography-tandem mass spectrometry, for the simultaneous determination of type-A (T-2 toxin, HT-2 toxin, diacetoxy-scirpenol, monoacetoxy-scirpenol, neosolaniol), type-B (nivalenol, deoxynivalenol, 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, fusarenon-X) and type-D trichothecenes (roridine and verrucarine) has been developed and validated on maize flour and oil. Analytes were separated on a analytical C18 column using acetonitrile as organic solvent and were detected by means of electrospray interface adding ammonium acetate (0.07 mM) to both mobile phases and selecting [M+NH4]+ as pseudomolecular ion; in order to confirm toxins identity, two multi-reaction-monitoring transitions were selected for each analyte. The analytical method was validated according to the European Commission Decision 2002/657/EC on both food matrices. The trichothecenes were extracted by means of matrix solid phase dispersion from maize flour with recoveries ≥ 79% and by means of liquid-liquid extraction from maize oil with recoveries ≥ 72%. The limits of detection were ≤ 17 ppb for maize flour, and ≤ 57 ppb for maize oil; according to indications of Regulation 856/2005/EC, the decision limit (CCalfa) and detection capability (CCbeta) were estimated only for deoxynivalenol. The developed method was applied to detect the occurrence of trichothecenes residues in some commercial products; however positive samples did not exceed law level

Development and validation of two multiresidue liquid chromatography tandem mass spectrometry methods based on a versatile extraction procedure for isolating non-steroidal anti-inflammatory drugs from bovine milk and muscle tissue

The main difficulties in analysing non-steroidal anti-inflammatory drugs (NSAIDs) in food and biological samples are due to the tight non-covalent interactions established with matrix proteins and the amount of occurring fatty material. The present paper describes an effective extraction procedure able to isolate fifteen NSAIDs (acetaminophen, salicylic acid, ibuprofen, diclofenac, flunixin and its metabolite 5-hydroxy-flunixin, nimesulide, phenylbutazone, meclofenamic acid, tolfenamic acid, meloxicam, carprofen, ketoprofen, naproxen and etodolac) from bovine milk and muscle tissue through two succeeding steps: (a) deproteinisation/extraction with organic solvent, essential to lower the medium dielectric constant and, therefore, to release the analytes from matrix; (b) SPE clean-up on OASIS cartridges. Lipids were easily removed during low-temperature centrifugations. The advantages of the developed procedure pertain to the efficient removal of the fat substances (very low matrix effect and high recovery yields) and its versatility, since it can be applied both to milk and muscle with few adjustments due to the diversity of the two matrices. Ion-pairing reversed-phase chromatography combined with the negative electrospray detection was able to achieve low detection capabilities (CCβs) for all analytes and, in particular, for diclofenac whose Maximum Residue Limit (MRL) in milk is 0.1 μg kg-1. The methods were validated according to the guidelines of the Commission Decision 2002/657/EC and then applied for a small monitoring study. A number of samples showed traces of salicylic acid (SA), but its occurrence was not ascribed to a misuse of drugs (aspirin, salicylic acid) since SA, accumulating in plants in response to a pathogen attack, may be introduced into the food chain. © 2012 Springer-Verlag

Residue analysis of cortisonics in bovine milk by LC tandem MS

A new method of analysis, based on liquid chromatography-tandem mass spectrometry, was developed for the simultaneous determination of twelve steroidal anti-inflammatory drugs in cow milk. This analytical method was validated according to the European Commission Decision 2002/657/EC. Analytes were separated by ion-suppression reversed-phase liquid chromatography, due to weakly acidic nature of the selected cortisonics. Dexamethasone tetradeuterated was chosen as internal standard. Detection was in positive ion mode, using a high flow electrospray interface (TurboIonSpray). Two Multi Reaction Monitoring (MRM) transitions each analyte were selected. Analytes’ recovery in milk was made up of two steps: 1) sample deproteinization by trifluoroacetic acid; 2) solid phase extraction (SPE) by means of C18 as adsorbent and methanol as eluent. Recoveries were ≥ 70% with relative standard deviations minor than 10%. Matrix effect has become unimportant owing to the efficacy of the extraction procedure in interfering substances removal and to a suitable internal standard. In order to evaluate matrix effect, calibration curves in solvent were compared with calibration curves obtained by blank extracts spiked with analytes. Method limits were evaluated on the quantifier transition (less intense), according to the European Commission Decision 2002/657/EC for decision limit (CCalfa) and detection capability (CCbeta) assessment. Monitoring results on different fresh whole milk brands, have shown in some cases a suspected positivity. Hydrocortisone and Cortisone Acetate were found in these samples at levels between CCalfa and CCbeta. This LC-MS/MS study allowed to observe Triamcinolone transformation during the evaporation step, that could explain low recovery data found in literature