J P Antignac

École Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes-Atlantique, Naoned, Pays de la Loire, France

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Publications (14)31.69 Total impact

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    ABSTRACT: BPA-containing products are widely used in foodstuffs packaging as authorized within the European Union (UE no. 10/2011). Therefore, foods and beverages are in contact with BPA which can migrate from food contact material to foodstuffs. An accurate assessment of the exposure of the consumers to BPA is crucial for a non-ambiguous risk characterization. In this context, an efficient analytical method using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS), in the selected reaction monitoring (SRM) mode, was developed for the quantification of BPA in foodstuffs at very low levels (<0.5μgkg(-1)). A standard operating procedure, based on the combination of two successive solid phase extractions (SPE), was developed for various liquid and solid foodstuffs. The use of (13)C12-BPA as internal standard allowed accurate quantification of BPA by isotopic dilution. Control charts based on both blank and certified materials have been implemented to ensure analytical data quality. The developed analytical method has been validated according to in-house validation requirements. R(2) was better than 0.9990 within the range [0-100μgkg(-1)], the trueness was 4.2%. Repeatability and within-laboratory reproducibility ranged from 7.5% to 19.0% and 2.5% to 12.2%, respectively, at 0.5 and 5.0μgkg(-1) depending on the matrices tested for. The detection and quantification limits were 0.03 and 0.10μgkg(-1), respectively. The reporting limit was 0.35μgkg(-1), taking into account the mean of the laboratory background contamination. The global uncertainty was 22.2% at 95% confidence interval.
    Journal of Chromatography A 08/2014; · 4.61 Impact Factor
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    ABSTRACT: The emerging field of metabolomics, aiming to characterize small molecule metabolites present in biological systems, promises immense potential for different areas such as medicine, environmental sciences, agronomy… The purpose of this paper is to guide the reader through the history of the field, then through the main steps of the metabolomics workflow, from study design to structure elucidation, and help the reader to understand the key phases of a metabolomics investigation and the rationale underlying the protocols and techniques used. This article is not intended to give standard operating procedures as several papers related to this topic were already provided, but is designed as a tutorial aiming to help beginners understanding the concept and challenges of Mass Spectrometry-based metabolomics. A real case example is taken from the literature to illustrate the application of the metabolomics approach in the field of doping analysis. Challenges and limitations of the approach are then discussed along with future directions in research to cope with these limitations. This Tutorial is part of the International Proteomics Tutorial Programme (IPTP18).This article is protected by copyright. All rights reserved
    Proteomics 08/2014; · 4.43 Impact Factor
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    ABSTRACT: Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC-MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination values<LOD considered as 0), high freshwater fish consumers appear as the most exposed to PFOS (7.5ng.kg(-1) bw.d(-1)), PFUnA (1.3ng.kg(-1) bw.d(-1)), PFDA (0.4ng.kg(-1) bw.d(-1)) and PFHpS (0.03ng.kg(-1) bw.d(-1)) while high seafood consumers appear as the most exposed to PFOA (1.2ng.kg(-1) bw.d(-1)), PFNA (0.2ng.kg(-1) bw.d(-1)) and PFHxS (0.06ng.kg(-1) bw.d(-1)). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals.
    Science of The Total Environment 02/2014; · 3.16 Impact Factor
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    ABSTRACT: Experimental studies have shown that dioxin-like chemicals may interfere with aspects of the endocrine system including growth. However, human background population studies are, however, scarce. We aimed to investigate whether early exposure of healthy infants to dioxin-like chemicals was associated with changes in early childhood growth and serum IGF1. In 418 maternal breast milk samples of Danish children (born 1997-2001) from a longitudinal cohort, we measured polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls (pg or ng/g lipid) and calculated total toxic equivalent (total TEQ). SDS and SDS changes over time (ΔSDS) were calculated for height, weight, BMI, and skinfold fat percentage at 0, 3, 18, and 36 months of age. Serum IGF1 was measured at 3 months. We adjusted for confounders using multivariate regression analysis. Estimates (in parentheses) correspond to a fivefold increase in total TEQ. TEQ levels in breast milk increased significantly with maternal age and fish consumption and decreased with maternal birth year, parity, and smoking. Total TEQ was associated with lower fat percentage (-0.45 s.d., CI: -0.89; -0.04), non-significantly with lower weight and length at 0 months, accelerated early height growth (increased ΔSDS) (ΔSDS 0-18 months: +0.77 s.d., CI: 0.34; 1.19) and early weight increase (ΔSDS 0-18: +0.52 s.d., CI: 0.03; 1.00), and increased IGF1 serum levels at 3 months (+13.9 ng/ml, CI: 2.3; 25.5). Environmental exposure to dioxin-like chemicals was associated with being skinny at birth and with higher infant levels of circulating IGF1 as well as accelerated early childhood growth (rapid catch-up growth).
    Reproduction 01/2014; 147(4):391-9. · 3.56 Impact Factor
  • Water Science & Technology Water Supply 09/2013; 13(5):1302.
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    ABSTRACT: Glucocorticoids constitute a class of molecules widely used in animal husbandry. Some of these compounds are licensed for veterinary practices while their use for growth promoting purposes is prohibited within the European Union. In order to ensure the respect of the legislation and consumers safety, several methodologies have been proposed to monitor these substances in various products, including edible matrices for which a regulatory limit has been set up (MRL). An extended range of targeted analytes together with reduced time of analysis and cost are however still current challenges regularly revisited according to the continuous technological improvements. In this context, the aim of the present study was to develop and implement a new fast and multi-residue method based on UHPLC-MS/MS for the determination of twenty glucocorticoids in bovine milk, included the screening of the three regulated MRL compounds (dexamethasone, betamethasone and prednisolone). This validated method authorises such multi-analyte measurement within a 10min runtime while the signal specificity is ensured through the SRM acquisition mode. Decision limits and detection capabilities were calculated in the range of 0.001-0.363μgL(-1), which allows a very efficient control at low trace level for a potential illegal use of these substances. The performances obtained in terms of application range, selectivity and sensitivity were found to be significantly improved in comparison to other reported approaches either for screening or confirmation purposes: regarding linearity, correlation coefficients were above 0.98 within the range of 0.01-5.0μgL(-1), repeatability and reproducibility parameters ranged from 1 to 30% with the maximum relative standard deviation (RSD) observed for cortisone (30.1%). Stability of the stock solutions and minor changes in the standard operating procedure have been included for the determination of ruggedness of the method. Identification was systematically ensured according to 4 identification points, RSD of transitions ratio (T2/T1) ranged from 3.2% and 19.3% and the RSD of the retention time was lower than 0.25%.
    Journal of Chromatography A 04/2013; · 4.61 Impact Factor
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    ABSTRACT: In recent decades, many toxicological tests based on in vivo or in vitro models, mainly from mammalian (rat-mouse) and fish species, were used to assess the risks raised by contact or ingestion of molecules of pharmaceutical, agricultural, or natural origin. But no, or few, in vitro tests using other non-mammalian models such as bird have been explored despite their advantages: the embryonic gonads of birds have a high plasticity of development sensitive to estrogen, and sperm production is nearly two times faster than in rodents. Hence, we have established an in vitro culture of germ cells and somatic cells from chicken post-natal testis, and we have evaluated the sensitivity against the endocrine disruptor compound mono-(2-ethylhexyl) phthalate (MEHP) in comparison to previous studies using rodent and human models. After 96 h of exposure in presence of 10 μM MEHP, chicken seminiferous tubules cultures present a structural alteration, a reduction in cell proliferation and in germ cells population. Apoptosis of germ and somatic cells increases in presence of 1 μM MEHP. Furthermore, MEHP does not affect inhibin B and lactate production by Sertoli cells. These results are in accordance with previous studies using rat, mice, or human culture of testicular cells and in similar range of exposures or even better sensitivity for some "end-points" (biological parameters). In conclusion, the establishment of this postnatal testicular cells culture could be considered as an alternative method to in vivo experiments frequently used for evaluating the impact on the terrestrial wildlife species. This method could be also complementary to mammal model due to the limiting number of animals used and its elevated sensitivity.
    Environmental Science and Pollution Research 01/2013; · 2.76 Impact Factor
  • Euroresidue VIIth Conference; 05/2012
  • Euroresidue VIIth Conference; 05/2012
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    ABSTRACT: The occurrence of the main steroid hormones (oestrone, 17alpha-oestradiol, 17beta-oestradiol, 17alpha-testosterone, 17beta-testosterone, dehydroepiandrosterone, 4-androstenedione), especially in milk and eggs, was investigated. An analytical method based on GC-MS/MS was developed for steroid measurement at an ultra-trace level in food products. The limits of detection for oestrogens were about 5 and 30 ng kg(-1) in milk and eggs, respectively. For androgens, the limits of detection were around 10 and 50 ng kg(-1) in milk and eggs, respectively. The method was applied to milk and egg samples collected in a French supermarket. In milk, oestrone was found at levels between 100 and 300 ng l(-1), while 17beta-oestradiol levels were estimated to be near 20 ng l(-1). 17alpha-testosterone was found to be from 50 ng l(-1) in skimmed milk to 85 ng l(-1) in whole milk. In egg samples, oestrone and 17beta-oestradiol were found at 1.5 and 0.9 microg kg(-1), respectively, while 17alpha-oestradiol was found to be in lower concentrations (i.e. around 0.55 microg kg(-1)). Regarding androgens, 17alpha- and 17beta-testosterone were estimated at 1.9 and 1.3 microg kg(-1), respectively. These results represent a first attempt to estimate the food exposure to steroid hormones. In the future, the collection of additional data should permit the comparison between this exogenous dietary intake and the daily endogenous production in pre-pubertal children as a basis of risk assessment regarding endocrine disruption linked to these molecules for this critical population.
    Food Additives and Contaminants 01/2008; 24(12):1358-66. · 2.13 Impact Factor
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    ABSTRACT: Fifty years after the discovery of natural corticosteroid hormones and their anti-inflammatory properties many synthetic derivatives of these molecules are now available. Most are widely used in human and veterinary medicine, legally but under regulated conditions. These compounds can also be used as growth promoters in animal breeding, although such use is illegal in Europe. Consequently, analytical methods have been developed to monitor use of corticosteroids in cattle. This paper, based on the authors experience and the main relevant literature, describes the different mass spectrometric approaches used for measurement of corticosteroid residues (parent drug, metabolites, and esters) in biological matrices (urine, meat, hair), including gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–tandem mass spectrometry (LC–MS2). The respective advantages of liquid chromatography and gas chromatography, in conjunction with different derivatisation reactions, are discussed. The behavior of corticosteroids with different ionization techniques is also discussed. Application to monitoring corticosteroid misuse and to investigation of pharmacokinetics and metabolism in bovine species is described and new data are presented relating to elimination and hair fixation kinetics for free and ester forms and the nature and proportions of corticosteroid phase I and phase II metabolites. Finally, this work reviews ten years experience of the use of a variety of mass spectrometric techniques for analysis of corticosteroids in animals produced as food.
    Chromatographia 02/2004; 59:S13-S22. · 1.44 Impact Factor
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    ABSTRACT: A new method has been developed for the simultaneous measurement, in a reduced plasma sample, of concentration and 13C-isotopic enrichment of acetic, propionic, butyric, lactic, acetoacetic and beta-hydroxybutyric acids by gas chromatography coupled to mass spectrometry. After plasma deproteinisation, a diethylic extraction and a N-tert.-butyldimethylsilyl-N-methyltrifluoroacetamide derivatisation were performed. Both diethyl extraction and derivatisation procedures were optimised using the central composite designs methodology. The optimised method provides good linearity, intra-day and within-day repeatability. Except for beta-hydroxybutyric (49 microM) and acetoacetic acid (5 microM), detection limits were ranging between 0.2 and 0.7 microM allowing uses of this method for colonic metabolism studies.
    Journal of Chromatography B 03/2003; 784(2):395-403. · 2.49 Impact Factor
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    ABSTRACT: A fast and efficient multi-residue extraction-purification procedure was developed for 12 corticosteroids in biological matrices (hair, urine and meat), in order to control their illegal use as growth promoters in cattle. Detection and identification of the analytes were achieved using a previously described LC-MS-MS method based on negative electrospray ionisation and a triple quadrupole analyser. The presented procedures included acid (hair) or enzymatic (urine and meat) hydrolysis, C18 reversed-phase SPE, Na2CO3 liquid-liquid clean-up and SiOH normal-phase SPE. The detection limits of the developed methods were between 2.9 and 9.3 pg/mg (ppb) for hair samples and in the 40 - 70 pg/g (ppt) range for the urine or meat samples. The acid hydrolysis used for corticosteroid extraction in hair was optimised using an experimental design and response surface methodology. Achieved performances were linked to a physico-chemical approach based on the corticosteroids specific C17 side-chain. This original multi-residue and multi-matrices analytical methodology will be used for further metabolism studies.
    Journal of chromatography. B, Biomedical sciences and applications 07/2001; 757(1):11-9.
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    ABSTRACT: A screening method based on liquid chromatography/electrospray tandem mass spectrometry was developed in order to control the illegal use of corticosteroids as growth promoters in cattle. The objective was the detection of low residue levels of corticosteroids or metabolites in biological matrices. Relative to other studies published on this subject, the present work focused on enhancing specificity and sensitivity. Firstly, fragmentation of corticosteroids by collision-induced dissociation was studied. In positive mode, the losses of H(2)O for each hydroxyl group fixed on the molecule, as well as the loss of HF or HCl for halogenated compounds, were observed. For higher collision energy, fragmentations in the B, C and D rings were induced. The negative mode was found to be more specific, inducing a cleavage of the C(20)-C(21) bond with concomitant loss of formaldehyde (CH(2)O). Secondly, three acquisition methods in the negative mode were studied and evaluated, recorded signals being the parent ion [M + acetate](-) and the two daughter ions, [M - H](-) and [M - H - CH(2)O](-). For dexamethasone, MS/MS instrumental detection limits of fragment ion and neutral loss scans, and of multiple reaction monitoring (MRM), were 250, 20 and 5 pg injected, respectively. The MRM method was then evaluated with the objective of use for the detection of corticosteroid residues in biological samples (urine, hair, muscle) and for a metabolism study.
    Rapid Communications in Mass Spectrometry 02/2000; 14(1):33-9. · 2.51 Impact Factor