RESUMO
Due to the absence of chromatographic separation, ambient ionization mass spectrometry had the potential to improve the throughput of control laboratories in the last decades and will soon be an excellent approach for on-site use as well. In this study, an atmospheric solids analysis probe (ASAP) with a single quadrupole mass analyzer has been evaluated to identify anabolic steroid esters rapidly. Sample introduction, applied scan time, and probe temperature were optimized for sensitivity. The in-source fragmentations of seventeen selected steroid esters, commonly found in illicit samples, were determined by applying different cone voltages (12, 20, 30, and 40 V). A spectral library was created for these steroid esters based on the four stages of in-source fragmentation spectra. The applicability of this method was demonstrated for the rapid identification of steroid esters in oily injection solutions, providing test results in less than 2 min.
Assuntos
Anabolizantes , Ésteres , Anabolizantes/análise , Espectrometria de Massas , Esteroides/análise , Congêneres da TestosteronaRESUMO
BACKGROUND: The bioavailability of dietary folate may be hampered by the need of the glutamate moieties to be deconjugated before absorption. Previous studies comparing the bioavailabilities of polyglutamyl and monoglutamyl folic acid had inconsistent results. OBJECTIVE: The objective was to estimate the bioavailability of polyglutamyl relative to that of monoglutamyl folic acid by using a sensitive stable-isotope approach that allowed for the administration of multiple low doses in humans. DESIGN: Twenty subjects aged 20-50 y ingested 2 capsules daily for 28 d; each capsule contained approximately 50 nmol [(13)C(6)]hexaglutamyl and approximately 50 nmol [(13)C(11)]monoglutamyl folic acid. Amounts of the isotopically labeled compounds in the capsules were verified by various methods. The degrees of isotopic enrichment of plasma 5-methyltetrahydrofolate with (13)C(6) and (13)C(11) were measured by using liquid chromatography tandem mass spectrometry, and the ratio of (13)C(6) to (13)C(11) ((13)C(6):(13)C(11)) in plasma on day 28 was used as a measure of their relative bioavailability. RESULTS: The (13)C(11):(13)C(6) in plasma 5-methyltetrahydrofolate reached equilibrium on day 4 and was 0.66 (95% CI: 0.58, 0.74) on day 28. The (13)C(11):(13)C(6) content in the capsules varied between 1.18 and 1.96. After correction for this ratio, the estimated bioavailability of hexaglutamyl relative to that of monoglutamyl folic acid was >/=78%. CONCLUSION: Multiple dosing of low amounts of labeled folic acid is a sensitive, accurate, and efficient method of measuring the relative bioavailability of folic acid compounds, provided that the administered doses can be reliably assessed.
Assuntos
Ácido Fólico/farmacocinética , Absorção Intestinal/efeitos dos fármacos , Tetra-Hidrofolatos/sangue , Complexo Vitamínico B/farmacocinética , Administração Oral , Adulto , Área Sob a Curva , Disponibilidade Biológica , Isótopos de Carbono , Cromatografia Líquida/métodos , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Feminino , Ácido Fólico/administração & dosagem , Ácido Fólico/química , Humanos , Masculino , Pessoa de Meia-Idade , Ácidos Pteroilpoliglutâmicos/administração & dosagem , Ácidos Pteroilpoliglutâmicos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/métodos , Complexo Vitamínico B/análise , Complexo Vitamínico B/químicaRESUMO
The abuse of esters of natural androgenic steroids in cattle fattening and sports is hard to control via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. In veterinary control strange findings of 17beta-testosterone and 17alpha-testosterone in urine are often ignored because of the lack of statistically sound reference data of naturally occurring levels. An interesting alternative for inconclusive urine analyses in veterinary control can be provided by the analysis of the administered steroids themselves, i.e. the analysis of intact steroid esters in hair. Unfortunately, the analysis of intact steroid esters is complicated not only by the vulnerability of the esters which precludes alkaline hydrolysis of the hair, but also by the wide polarity range of short and long-chain esters yielding very poor recoveries for either the one or the other. In this study, a multi-steroid esters LC/MS/MS screening method is presented for trace analysis of the synthetic intact esters of 17beta-testosterone and the undecylenate ester of 17beta-boldenone in bovine hair. The method, requiring only 200 mg of pulverised hair, features a mild digestion procedure using tris(2-carboxyethyl)phosphine hydrochloride (TCEP) and the use of four deuterium-labelled steroid esters as internal standards covering the wide polarity range of the analytes. In spiked hair samples for most of the analytes the limit of detection and the accuracy using isotope dilution were 2-5 ng/g and 97-105%, respectively. The applicability was demonstrated using hair samples from a controlled experiment in which six bovines were injected intramuscularly with two different doses of two commercial mixtures of testosterone esters, and with two different doses of boldenone undecylenate. Depending on the dose all administered testosterone- and boldenone esters were found to be incorporated in bovine hair following a single intramuscular injection, except testosterone propionate which dose might have been too low.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Cabelo/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Testosterona/análogos & derivados , Testosterona/análise , Animais , Bovinos , Ésteres , Padrões de Referência , Espectrofotometria Ultravioleta/métodosRESUMO
In 2013 the Dutch authorities issued a warning against a dietary supplement that was linked to 11 reported adverse reactions, including heart problems and in one case even a cardiac arrest. In the UK a 20-year-old woman, said to have overdosed on this supplement, died. Since according to the label the product was a herbal mixture, initial LC-MS/MS analysis focused on the detection of plant toxins. Yohimbe alkaloids, which are not allowed to be present in herbal preparations according to Dutch legislation, were found at relatively high levels (400-900 mg kg(-1)). However, their presence did not explain the adverse health effects reported. Based on these effects the supplement was screened for the presence of a ß-agonist, using three different biosensor assays, i.e. the validated competitive radioligand ß2-adrenergic receptor binding assay, a validated ß-agonists ELISA and a newly developed multiplex microsphere (bead)-based ß-agonist assay with imaging detection (MAGPIX(®)). The high responses obtained in these three biosensors suggested strongly the presence of a ß-agonist. Inspection of the label indicated the presence of N-isopropyloctopamine. A pure standard of this compound was bought and shown to have a strong activity in the three biosensor assays. Analysis by LC-full-scan high-resolution MS confirmed the presence of this 'unknown known' ß3-agonist N-isopropyloctopamine, reported to lead to heart problems at high doses. A confirmatory quantitative analysis revealed that one dose of the preparation resulted in an intake of 40-60 mg, which is within the therapeutic range of this compound. The case shows the strength of combining bioassays with chemical analytical techniques for identification of illegal pharmacologically active substances in food supplements.
Assuntos
Agonistas de Receptores Adrenérgicos beta 3/intoxicação , Antipirina/análogos & derivados , Depressores do Apetite/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Contaminação de Alimentos , Cardiopatias/etiologia , Preparações de Plantas/efeitos adversos , Agonistas de Receptores Adrenérgicos beta 3/análise , Alcaloides/análise , Alcaloides/toxicidade , Anabolizantes/efeitos adversos , Anabolizantes/química , Anabolizantes/intoxicação , Anabolizantes/normas , Antipirina/análise , Antipirina/intoxicação , Depressores do Apetite/química , Depressores do Apetite/intoxicação , Depressores do Apetite/normas , Técnicas Biossensoriais , Suplementos Nutricionais/análise , Suplementos Nutricionais/intoxicação , Suplementos Nutricionais/normas , Inspeção de Alimentos , Rotulagem de Alimentos , Doenças Transmitidas por Alimentos/etiologia , Doenças Transmitidas por Alimentos/mortalidade , Doenças Transmitidas por Alimentos/terapia , Cardiopatias/mortalidade , Cardiopatias/terapia , Hospitalização , Humanos , Internet , Países Baixos , Nootrópicos/efeitos adversos , Nootrópicos/química , Nootrópicos/intoxicação , Nootrópicos/normas , Pausinystalia/efeitos adversos , Pausinystalia/química , Substâncias para Melhoria do Desempenho/efeitos adversos , Substâncias para Melhoria do Desempenho/química , Substâncias para Melhoria do Desempenho/intoxicação , Substâncias para Melhoria do Desempenho/normas , Preparações de Plantas/química , Preparações de Plantas/intoxicação , Preparações de Plantas/normasRESUMO
The origin, i.e. natural occurrence or illegal treatment, of findings of 17alpha-boldenone (alpha-Bol) and 17beta-boldenone (beta-Bol) in urine and faeces of cattle is under debate within the European Union. A liquid chromatographic positive ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of 17beta-boldenone, 17alpha-boldenone and an important metabolite/precursor androsta-1,4-diene-3,17-dione (ADD), using deuterium-labelled 17beta-boldenone (beta-Bol-d3) as internal standard. Detailed sample preparation procedures were developed for a variety of sample matrices such as bovine urine, faeces, feed and skin swab samples. The method was validated as a quantitative confirmatory method according to the latest EU guidelines and shows good precision, linearity and accuracy data, and CCalpha and CCbeta values of 0.1-0.3 and 0.4-1.0 ng/ml, respectively. Currently, the method has been successfully applied to suspect urine samples for more than a year, and occasionally to faeces, feed and swab samples as well. Results obtained from untreated and treated animals are given and their impact on the debate about the origin of residues of 17beta-boldenone is critically discussed. Finally, preliminary data about the degree of conjugation of boldenone residues are presented and a simple procedure for discrimination between residues from abuse versus natural origin is proposed.
Assuntos
Androstadienos/análise , Ração Animal/análise , Bovinos , Fezes/química , Pele/química , Testosterona/análogos & derivados , Testosterona/análise , Anabolizantes/análise , Animais , Cromatografia Líquida , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray , Testosterona/química , Testosterona/urinaRESUMO
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of the four major enterolignan precursors [secoisolariciresinol, matairesinol, lariciresinol, and pinoresinol] in foods. The method consists of alkaline methanolic extraction, followed by enzymatic hydrolysis using Helix pomatia (H. pomatia) beta-glucuronidase/sulfatase. H. pomatia was selected from several enzymes based on its ability to hydrolyze isolated lignan glucosides. After ether extraction samples were analyzed and quantified against secoisolariciresinol-d8 and matairesinol-d6. The method was optimized using model products: broccoli, bread, flaxseed, and tea. The yield of methanolic extraction increased up to 81%, when it was combined with alkaline hydrolysis. Detection limits were 4-10 microg/(100 g dry weight) for solid foods and 0.2-0.4 microg/(100 mL) for beverages. Within- and between-run coefficients of variation were 6-21 and 6-33%, respectively. Recovery of lignans added to model products was satisfactory (73-123%), except for matairesinol added to bread (51-55%).
Assuntos
Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Lignanas/análise , Espectrometria de Massas/métodos , Plantas/química , Butileno Glicóis/análise , Furanos/análise , Hidrólise , Sensibilidade e EspecificidadeRESUMO
Bioassays are valuable tools for combating the illegal use of steroids in cattle fattening. Previously we described the construction and properties of a rapid and robust yeast androgen bioassay stably expressing the human androgen receptor (hAR) and yeast enhanced green fluorescent protein (yEGFP), the latter in response to androgens. In the present study this yeast androgen bioassay was validated as a qualitative screening method for the determination of androgenic activity in calf urine and animal feed. This validation was performed according to EC Decision 2002/657. 20 blank samples were spiked with testosterone, 17alpha-methyltestosterone, 19-nortestosterone, 17beta-trenbolone, 17beta-boldenone or 17alpha-methylboldenone at 2 or 15 ngmL(-1) in urine and 50 or 100 ngg(-1) in feed. All blank and spiked samples fulfilled the CCalpha and CCbeta criterions, meaning that all 20 blank samples gave signals below the determined decision limits CCalpha and were thus classified as compliant (alpha=1%). For each component, at least 19 out of the 20 spiked samples gave a signal above the CCalpha and were thus classified as suspect (beta=5%). The method was specific, and high amounts of dexamethasone did not interfere with the outcome of the test. Although high levels of 17alpha-ethynylestradiol can significantly inhibit the response obtained with low amounts of androgens, that situation is not relevant in veterinary practice. When stored at their specific conditions, the androgens in feed were stable for at least 91 days. Real urine samples from a national control program were screened and a representative part of the compliant and suspect samples were confirmed by gas chromatography-tandem mass spectrometry.
Assuntos
Androgênios/análise , Ração Animal/análise , Bioensaio/métodos , Bovinos/urina , Detecção do Abuso de Substâncias/métodos , Leveduras/metabolismo , Androgênios/metabolismo , Androgênios/urina , Animais , Proteínas de Fluorescência Verde/metabolismo , Humanos , Substâncias Luminescentes/metabolismo , Receptores Androgênicos/metabolismo , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
A lifetime controlled reference experiment has been performed using 42 veal calves, 21 males and 21 females which were fed and housed according to European regulations and common veterinary practice. During the experiment feed, water, urine and hair were sampled and feed intake and growth were monitored. Thus for the first time residue analysis data were obtained from guaranteed lifetime-untreated animals. The analysis was focused on the natural hormones estradiol and testosterone and their metabolites, on 17beta- and 17alpha-nortestosterone, on 17beta- and 17alpha-boldenone and androsta-1,4-diene-3,17-dione (ADD), and carried out by gas chromatography tandem mass spectrometry (GC/MS/MS), an estrogen bioassay and liquid chromatography (LC) MS/MS. Feed, water and hair samples were negative for the residues tested. Female calf urines showed occasionally low levels of 17alpha-estradiol and 17alpha-testosterone. On one particular sampling day male veal calf urines showed very high levels of 17alpha-testosterone (up to 1000 ng mL(-1)), accompanied by lower levels of estrone and 17beta-testosterone. Despite these extreme levels of natural testosterone, 17beta-boldenone was never detected in the same urine samples; even 17alpha-boldenone and ADD were only occasionally beyond CCalpha (maximum levels 2.7 ng mL(-1)). The data from this unique experiment provide a set of reference values for steroid hormones in calf urine and demonstrate that 17beta-boldenone is not a naturally occurring compound in urine samples.