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1.
Chemically modified steroids (designer steroids), including tetrahydrogestrinone and norbolethone, pose a threat to the integrity of the sport community. These compounds have recently been detected in urine specimens from athletes, resulting in temporary or permanent suspension from amateur and/or professional competition. Triple quadrupole mass spectrometers enable doping control laboratories to screen for unknown, anabolic, androgenic steroids utilizing precursor ion scans. On the basis of common dissociation patterns of steroids with common structural features, characteristic product ions were selected to serve as diagnostic markers for previously unidentified drugs or drug metabolites in human urine samples. An assay was established to complement standard screening procedures. Urine specimens were enzymically hydrolyzed, partitioned into ether, concentrated, and analyzed by precursor ion scanning. Spectra from samples fortified with eight standard compounds (methyltestosterone, ethyltestosterone, 1-testosterone, gestrinone, dihydrogestrinone, tetrahydrogestrinone, norbolethone, and propyltrenbolone) and one deuterium-labeled analog (d(4)-tetrahydrogestrinone) at 50 ng/ml of urine, had precursor ion peaks other than those from common endogenous steroids. Subsequent product ion scan experiments on precursor ions of peaks of unknown origin provided structural identification of the unknown compounds.  相似文献   

2.
The positive findings of norbolethone in 2002 and tetrahydrogestrinone in 2003 in human athlete samples confirmed that designer steroids were indeed being abused in human sports. In 2005, an addition to the family of designer steroids called ‘Madol’ [also known as desoxy‐methyltestosterone ( DMT )] was seized by government officials at the US–Canadian border. Two years later, a positive finding of DMT was reported in a mixed martial arts athlete's sample. It is not uncommon that doping agents used in human sports would likewise be abused in equine sports. Designer steroids would, therefore, pose a similar threat to the horseracing and equestrian communities. This paper describes the in vitro metabolism studies of DMT and five of its structural analogues with different substituents at the 17α position (R ? H, ethyl, vinyl, ethynyl and 2H3‐methyl). In addition, the in vivo metabolism of desoxy‐vinyltestosterone ( DVT ) in horses will be presented. The in vitro studies revealed that the metabolic pathways of DMT and its analogues occurred predominantly in the A‐ring by way of a combination of enone formation, hydroxylation and reduction. Additional biotransformation involving hydroxylation of the 17α‐alkyl group was also observed for DMT and some of its analogues. The oral administration experiment revealed that DVT was extensively metabolised and the parent drug was not detected in urine. Two in vivo metabolites, derived respectively from (1) hydroxylation of the A‐ring and (2) di‐hydroxylation together with A‐ring double‐bond reduction, could be detected in urine up to a maximum of 46 h after administration. Another in vivo metabolite, derived from hydroxylation of the A‐ring with additional double‐bond reduction and di‐hydroxylation of the 17α‐vinyl group, could be detected in urine up to a maximum of 70 h post‐administration. All in vivo metabolites were excreted mainly as glucuronides and were also detected in the in vitro studies. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

3.
The urinary metabolism of the irreversible aromatase inhibitor androsta‐1,4,6‐triene‐3,17‐dione was investigated. It is mainly excreted unchanged and as its 17β‐hydroxy analogue. For confirmation, 17β‐hydroxyandrosta‐1,4,6‐trien‐3‐one was synthesized and characterized by nuclear magnetic resonance (NMR) in addition to the parent compound. In addition, several reduced metabolites were detected in the post‐administration urines, namely 17β‐hydroxyandrosta‐1,4‐dien‐3‐one (boldenone), 17β‐hydroxy‐5β‐androst‐1‐en‐3‐one (boldenone metabolite), 17β‐hydroxyandrosta‐4,6‐dien‐3‐one, and androsta‐4,6‐diene‐3,17‐dione. The identification was performed by comparison of the metabolites with reference material utilizing gas chromatography/mass spectrometry (GC/MS) of the underivatized compounds and GC/MS and GC/tandem mass spectrometry (MS/MS) of their trimethylsilyl (TMS) derivatives. Alterations in the steroid profile were also observed, most obviously in the androsterone/testosterone ratio. Even if not explicitly listed, androsta‐1,4,6‐triene‐3,17‐dione is classified as a prohibited substance in sports by the World Anti‐Doping Agency (WADA) due to its aromatase‐inhibiting properties. In 2006 three samples from human routine sports doping control tested positive for metabolites of androsta‐1,4,6‐triene‐3,17‐dione. The samples were initially found suspicious for the boldenone metabolite 17β‐hydroxy‐5β‐androst‐1‐en‐3‐one. Since metabolites of androst‐4‐ene‐3,6,17‐trione were also present in the urine samples, it is presumed that these findings were due to the administration of a product like ‘Novedex Xtreme’, which could be easily obtained from the sport supplement market. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

4.
One potential explanation for the presence of beta-boldenone in calf urine is contamination of the sample with feces containing beta-boldenone. It has been demonstrated that after oral and intramuscular administration of beta-boldenone esters, several metabolites are formed and excreted in urine. One of the (minor) metabolites is 6beta-hydroxy-17alpha-boldenone. This paper describes an analytical method that can discriminate between unconjugated boldenone, its glucuronide- and sulphate-conjugates, 6beta-hydroxy-17alpha/beta-boldenone and coprostanol, a marker for fecal contamination. The method was applied to all samples suspected to contain boldenone within the Dutch National Residue Control Plan. Approximately 10,000 samples of urine were screened (LC-MS) in 2004-2005 by VWA-East, one of the official Dutch control laboratories, from which 261 samples were suspected to contain boldenone. These samples were all analyzed for their conjugation state, 6beta-hydroxy-17alpha/beta-boldenone and for the presence of coprostanol. Alfa-boldenone, the major metabolite in bovine urine after boldenone-ester administration, was found in a large number of these samples. The presence of alpha-boldenone was proven also to be a result of fecal contamination. None of the samples tested contained residues of the metabolite 6beta-hydroxy-17alpha/beta-boldenone. Not finding this metabolite indicates that the origin of alpha-boldenone-conjugates is endogenous. The results confirm that the presence of unconjugated beta-boldenone and alpha-boldenone conjugates next to alpha-boldenone are no indicators for illegal administration of boldenone-esters. No indications were obtained that conjugated beta-boldenone can be of endogenous origin.  相似文献   

5.
We developed a rapid, sensitive, and automated analytical system to determine the delta15N, delta18O, and Delta17O values of nitrous oxide (N2O) simultaneously in nanomolar quantities for a single batch of samples by continuous-flow isotope-ratio mass spectrometry (CF-IRMS) without any cumbersome and time-consuming pretreatments. The analytical system consisted of a vacuum line to extract and purify N2O, a gas chromatograph for further purification of N2O, an optional thermal furnace to decompose N2O to O2, and a CF-IRMS system. We also used pneumatic valves and pneumatic actuators in the system so that we could operate it automatically with timing software on a personal computer. The analytical precision was better than 0.12 per thousand for delta15N with >4 nmol N2O injections, 0.25 per thousand for delta18O with >4 nmol N2O injections, and 0.20 per thousand for Delta17O with >20 nmol N2O injections for a single measurement. We were also easily able to improve the precision (standard errors) to better than 0.05 per thousand for delta15N, 0.10 per thousand for delta18O, and 0.10 per thousand for Delta17O through multiple analyses with more than four repetitions with 190 nmol samples using the automated analytical system. Using the system, the delta15N, delta18O, and Delta17O values of N2O can be quantified not only for atmospheric samples, but also for other gas or liquid samples with low N2O content, such as soil gas or natural water. Here, we showed the first ever Delta17O measurements of soil N2O.  相似文献   

6.
17 alpha-Boldenone (17 alpha-BOL) and/or 17 beta-boldenone (17 beta-BOL) appear occasionally in fecal matter of cattle. In addition to 17 alpha-BOL, a whole array of boldenone related substances can be found in the same samples. In vitro experiments with microsomal liver preparations and isolated hepatocytes combined with the excretion profiles found in urine and feces samples of in vivo experiments made it possible to identify several metabolites of 17 beta-BOL in 17 beta-BOL positive feces samples. In one animal treated with 17 beta-BOL, no 17 beta-BOL or its metabolites were present before treatment and most of these compounds disappeared gradually in time after the treatment was stopped. It is not clear what the origin is of 17 alpha-BOL and boldenone metabolites in samples screened routinely for the abuse of anabolic steroids and considered to be 'negative' because of the absence of 17 beta-BOL since other workers showed some evidence that 17 alpha-BOL can be of endogenous origin. However, in our hands, most of these 17 alpha-BOL positive samples, obtained during routinely performed screenings of cattle, contained large amounts of delta 4-androstene-3,17-dione (AED), which normally is absent from routinely screened negative samples. Furthermore, AED was absent in all samples obtained from the animals treated with 17 beta-BOL. We have no direct evidence that 17 alpha-BOL or 17 beta-BOL is of endogenous origin.  相似文献   

7.
DHEA (3β-hydroxy-androst-5-en-17-one) is a natural steroid prohormone. Despite a lack of information on the effect, DHEA and other prohormones are frequently used as a food supplement by body-builders. DHEA is suspected for growth promoting abuse in cattle as well. Considering the latter, urine samples from a previous exposure study in which calves were exposed to 1 g DHEA per day for 7 days, were used. The calves were divided in three groups: one orally treated, one intramuscularly injected, and a control group. The effect of this treatment on the urinary profile of several precursors and metabolites of DHEA was investigated. Urine samples were collected several days before and during the 7 days of administration and were submitted to a clean-up procedure consisting of a separation of the different conjugates (free, glucuronidated, and sulfated forms) of each compound on a SAX column (Varian). An LC-MS/MS method was developed for the detection and quantification of several metabolites of the pathway of DHEA including 17α- and 17β-testosterone, 4-androstenedione, 5-androstenediol, pregnenolone, and hydroxypregnenolone. Elevated levels of DHEA, 5-androstenediol, and 17α-testosterone were observed in the free and sulfated fraction of the urine of the treated calves, thus indicating that the administered DHEA is metabolized mainly by the ∆5-pathway with 5-androstenediol as the intermediate. Sulfoconjugates of DHEA and its metabolites were found to constitute the largest proportion of the urinary metabolites. The free form was also present, but in a lesser extent than the sulfated form, while glucuronides were negligible.  相似文献   

8.
A rapid and sensitive method for the analysis of 17alpha-ethinylestradiol (EE2) in environmental aqueous samples has been developed. Aquatic samples were extracted using liquid-liquid extraction, and organic phase extracts were concentrated and derivatized with dansyl chloride. Analysis was performed using high-performance liquid chromatography with positive electrospray ionization and tandem mass spectrometry (HPLC/ESI-MS/MS). Deuterated 17alpha-ethinylestradiol was used as internal standard and was added to samples before extraction. A limit of quantitation of 1 ng/L was obtained using a 25 mL aqueous sample. The average recovery of EE2 spiked into a 25 mL tapwater sample was 100%. This highly sensitive quantitation method is useful for measuring low levels of EE2 in aqueous environmental samples.  相似文献   

9.
A simple and sensitive direct injection chromatographic procedure is developed for the determination of heroin, two of its metabolites (morphine and 6-monoacetylmorphine (6-MAM)), and benzoylecgonine (a metabolite of cocaine) in serum samples. The proper resolution of the four substances is obtained with a chemometrics approach, where the retention is modelled as a first step using the retention factors obtained in a limited number of mobile phases. Afterwards, an optimisation criterion that takes into account the position and shape of the chromatographic peaks is applied. The mobile phase selected to carry out the analysis was 0.1 mol L(-1) SDS-4% (v/v) butanol buffered at pH 7, in which the separation is performed in less than 18 min. The limits of quantification were in the 17-36 ng mL(-1) range. Intra- and inter-day assay accuracy and precision (below 3%) were obtained following ICH guidelines. The method developed was applied to the determination of the drugs studied in serum samples with good recoveries (90-104%). Serum samples from subjects that have been ingested cocaine and heroin were also analysed. The samples were injected directly in the chromatographic system without any pretreatment.  相似文献   

10.
A method for determination of lead, cadmium, zinc, copper, and iron by atomic absorption spectrometry (AAS) after microwave digestion was subjected to a collaborative study in which 16 laboratories participated [including users of inductively coupled plasma (ICP) and ICP-mass spectrometry (MS)]. The types of samples included in the study were minced fish, wheat bran, milk powder, bovine and pig liver, mushroom, 2 simulated diets, and bovine muscle; the last 4 were certified reference materials. These were analyzed as single (4 samples), double blind (1 sample), or split level (2 samples) samples. Before the collaborative study, a pretrial was conducted in which 4 ready-made solutions and one fish tissue sample were analyzed for Pb and Cu. The reproducibility relative standard deviation (RSDR) values, for results above the detection limit, ranged from 59% at 0.155 mg/kg to 16% at 1.62 mg/kg for Pb, from 28% at 0.0124 mg/kg to 11% at 0.482 mg/kg for Cd, from 9.3% at 35.3 mg/kg to 1.7% at 147 mg/kg for Zn, from 39% at 0.241 mg/kg to 3.0% at 63.4 mg/kg for Cu, and from 17% at 7.4 mg/kg to 5.9% at 303 mg/kg for Fe. The RSDR values agreed well with the norms described by the International Union of Pure and Applied Chemistry. As a complement to the AAS determinations, a number of laboratories analyzed the samples either by ICP or by ICP-MS. The results of these analyses agreed well with the AAS results. On the basis of the results of the collaborative study, the method was adopted Official First Action by AOAC INTERNATIONAL.  相似文献   

11.
12.
17beta-Nortestosterone (17betaN) is illegally used in livestock as a growth promoter and its endogenous production has been described in some animals, such as adult boars. In this paper, the metabolism of 17betaN in boars has been studied by gas chromatography/mass spectrometry (GC/MS) in order to identify markers of the exogenous administration. Administration studies of intramuscular 17betaN laurate to male pigs were performed. Free, sulphate and glucuronide fractions of the urine samples were separated and the steroids present were quantified by GC/MS. 17betaN was detected in some pre-administration samples. After administration, 17betaN, norandrosterone, noretiocholanolone (NorE), norepiandrosterone, 5beta-estrane-3alpha,17beta-diol and 5alpha-estrane-3beta,17beta-diol were detected in different fractions, being the most important metabolites, 17betaN excreted as a sulphate and free NorE. Samples collected in routine controls were also analyzed by GC/MS to identify endogenous compounds. 17betaN, norandrostenedione and estrone were detected in almost all the samples. No other 17betaN metabolites were detected. According to these results, the detection by GC/MS of some of the 17betaN metabolites described above, different from 17betaN, could be indicative of the exogenous administration of 17betaN to boars.  相似文献   

13.
The bacterial denitrification method for isotopic analysis of nitrate using N(2)O generated from Pseudomonas aureofaciens may overestimate delta(15)N values by as much as 1-2 per thousand for samples containing atmospheric nitrate because of mass-independent (17)O variations in such samples. By analyzing such samples for delta(15)N and delta(18)O using the denitrifier Pseudomonas chlororaphis, one obtains nearly correct delta(15)N values because oxygen in N(2)O generated by P. chlororaphis is primarily derived from H(2)O. The difference between the apparent delta(15)N value determined with P. aureofaciens and that determined with P. chlororaphis, assuming mass-dependent oxygen isotopic fractionation, reflects the amount of mass-independent (17)O in a nitrate sample. By interspersing nitrate isotopic reference materials having substantially different delta(18)O values with samples, one can normalize oxygen isotope ratios and determine the fractions of oxygen in N(2)O derived from the nitrate and from water with each denitrifier. This information can be used to improve delta(15)N values of nitrates having excess (17)O. The same analyses also yield estimates of the magnitude of (17)O excess in the nitrate (expressed as Delta(17)O) that may be useful in some environmental studies. The 1-sigma uncertainties of delta(15)N, delta(18)O and Delta(17)O measurements are +/-0.2, +/-0.3 and +/-5 per thousand, respectively.  相似文献   

14.
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.  相似文献   

15.
A method is reported for the sensitive, simultaneous determination of mono- (MFA), di- (DFA), and trifluoroacetates (TFA) by ion chromatography (IC). These species were separated using a Dionex AS17 anion-exchange column employed with a potassium hydroxide gradient (via a Dionex EG40 eluent generator) and suppressed conductivity detection. The fluoroacetates were successfully separated from a range of inorganic and organic species likely to be present in environmental samples, in a total analysis time of 35 min (including re-equilibration of the column). Detection limits for mono-, di- and trifluoroacetate were 21, 38 and 36 microg/l, respectively, determined using a signal-to-noise ratio of 3, and were obtained using a sample injection volume of 50 microl. Precision was less than 0.83% relative standard deviation (RSD) for replicate injections performed over a period of 30 days. The method was applied to the determination of monofluoroacetate in river water samples and also in carrot baits.  相似文献   

16.
A novel 17β‐estradiol molecularly imprinted polymer was grafted onto the surface of initiator‐immobilized silica by surface‐initiated atom transfer radical polymerization. The resulting molecularly imprinted polymer was characterized by elemental analysis and thermogravimetric analysis. The binding property of molecularly imprinted polymer for 17β‐estradiol was also studied with both static and dynamic methods. The results showed that the molecularly imprinted polymer possessed excellent recognition capacity for 17β‐estradiol (180.65 mg/g at 298 K), and also exhibited outstanding selectivity for 17β‐estradiol over the other competitive compounds (such as testosterone and progesterone). Then, the determination of trace 17β‐estradiol in beef samples was successfully developed by using molecularly imprinted polymer solid‐phase extraction coupled with high‐performance liquid chromatography. The limit of detection was 0.25 ng/mL, and the amount of 17β‐estradiol in beef samples was detected at 2.83 ng/g. This work proposed a sensitive, rapid, reliable, and convenient approach for the determination of trace 17β‐estradiol in complicated beef samples.  相似文献   

17.
Four different quantification methods for the capillary gas chromatographic determination of medium-chain fatty acids (6:0-12:0) and myristic acid in human milk samples, using a split injector, were compared. Odd-carbon-numbered fatty acids (5:0-17:0) were added as internal standards. Each medium-chain fatty acid and myristic acid was calculated on the basis of: the peak area of the internal standard with one methylene group less; the peak area of the internal standard with one methylene group more; half the sum of the peak areas of the internal standards with one methylene group less and more (bracketting method); the peak area of 17:0. The peak-area ratio of each analyte and 17:0 in a standard was found to be subject to an unacceptably high coefficient of variation. From the methods using internal standards with one methylene group more and less, the bracketting method was found to be the best, resulting in recoveries close to 100%, with the lowest coefficients of variation. The method was applied for the determination of the fatty acid composition of mature milk samples of 47 Cura?aoan women.  相似文献   

18.
An immunoaffinity precolumn (immuno precolumn) packed with Sepharose-immobilized polyclonal antibodies against the anabolic hormone 17 beta-19-nortestosterone (beta-19-NT) was used for the selective on-line pretreatment of raw extracts of urine, bile and tissue samples by high-performance liquid chromatography. Using UV detection (247 nm), beta-19-NT and its metabolite 17 alpha-19-nortestosterone (alpha-19-NT) can be determined in biological samples with a detection limit of 0.05 microgram/kg. Owing to the high clean-up efficiency of the immuno precolumn and the large sample volumes used, confirmation by gas chromatography-mass spectrometry is possible at this level. In urine samples from a calf treated with 19-nortestosterone 17 beta-laurate, the maximum concentrations of beta-19-NT (1.3 micrograms/l) and alpha-19-NT (3.1 micrograms/l) were found seven days after intramuscular administration. In a bile sample from this calf only alpha-19-NT (55 microgram/l) was detected. In meat samples from three treated calves, the concentration of beta-19-NT varied from 0.1 to 1.6 micrograms/kg and no alpha-19-NT could be detected. In liver samples from these calves, the concentrations of beta-19-NT and alpha-19-NT were less than 0.05-0.1 and 0.5-0.9 micrograms/kg, respectively. In the corresponding kidney samples, the concentrations of beta-19-NT and alpha-19-NT were 0.4-0.5 and 0.5-1.6 micrograms/kg, respectively. The application of the same immuno precolumn to the determination of 17 beta- and 17 alpha-trenbolone, two structurally related steroids, is also demonstrated.  相似文献   

19.
Isocratic HPLC with potentiometric detection is used for the determination of some 17‐ketosteroids (17‐KS), e.g., androsterone, dehydroepiandrosterone and estrone, and their respective sulfated conjugates (17‐KSS). Glassy carbon or composite electrodes containing a mixture of graphite and poly(vinyl chloride), PVC, were used as substrate electrodes. These substrates were covered either by montmorillonite or potassium tetrakis(p‐chlorophenyl) borate containing PVC‐based rubber phase membranes. The neutral 17‐KS compounds were derivatized with Girard's reagent P (GP) to obtain cationic pyridinium acetohydrazones prior to the HPLC/potentiometric detection assay. No side reactions were observed, and the GP itself was not interfering. The method yielded accurate and reproducible results and was applicable to samples containing down to micromolar concentrations. Next, the 17‐KSS compounds, acting as anionic charged molecules, were determined directly in human urine samples with the HPLC/potentiometry combination without preliminary derivatization. For this purpose, a new anion‐sensitive potentiometric electrode was developed using a macrocyclic polyamine containing, PVC‐based, rubber phase membrane. The three 17‐KSS compounds were also determined accurately down to micromolar concentrations. Especially, the main androgen metabolites as dehydroepiandrosterone sulfate and androsterone sulfate could be selectively determined with a developed potentiometric sensor in human urine samples without time‐consuming cleanup and preconcentration step.  相似文献   

20.
A method for the simultaneous determination of 16 pharmaceutical compounds in three types of sewage sludge (primary, secondary and anaerobically digested dehydrated sludge), compost and sediment samples is described. Pharmaceutical compounds evaluated were nonsteroidal anti‐inflammatory drugs (acetaminophen, diclofenac, ibuprofen, ketoprofen, naproxen and salicylic acid), antibiotics (sulfamethoxazole and trimethoprim), an anti‐epileptic drug (carbamazepine), a β‐blocker (propranolol), a nervous stimulant (caffeine), estrogens (17α‐ethinylestradiol, 17β‐estradiol, estriol and estrone) and lipid regulators (clofibric acid, metabolite of clofibrate and gemfibrozil). The method is based on the ultrasonic‐assisted extraction, clean‐up by SPE and analytical determination by HPLC with diode array and fluorescence detectors. The best extraction recoveries were achieved in a three‐step extraction procedure with methanol and acetone as extraction solvents. Extraction recoveries of several pharmaceutical compounds as caffeine were highly dependent on the type of sample evaluated. The applicability of the method was tested by analyzing primary, secondary and anaerobically digested dehydrated sludge, compost and sediment samples from Seville (Southern Spain). Ten of the sixteen pharmaceutical compounds were detected in sludge samples and five in compost and sediment samples. The highest concentration levels were recorded for ibuprofen in sewage samples, whereas salicylic acid and 17α‐ethinylestradiol were detected in all of the samples analyzed.  相似文献   

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