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1.
Choi MH  Chung BC 《The Analyst》1999,124(9):1297-1300
An efficient method for the simultaneous determination of eight steroids, androstenedione, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), testosterone, androsterone, etiocholanolone, progesterone and pregnenolone, in human hair by gas chromatography-mass spectrometry (GC-MS) using d3-testosterone as internal standard is described. The method involves alkaline digestion, liquid-liquid extraction and subsequent conversion to mixed pentafluorophenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive analysis in the selected ion monitoring (SIM) mode. This method showed good overall repeatability and reproducibility of 4.88-11.24 and 3.19-9.58%, respectively. For the first time, the quantification of DHT, DHEA and pregnenolone in human hair has been achieved by GC-MS, testosterone was also quantified. The detection of four steroids in hair samples was possible in the concentration range 0.12-8.45 ng g-1. The other four steroids, androstenedione, androsterone, etiocholanolone and progesterone, were not detected. The detection limits for SIM of the steroids varied in the range 0.02-0.5 ng g-1, and the SIM responses were linear with correlation coefficients varying from 0.991 to 0.996 for most of the steroids studied. The concentrations of the four steroids detected were different in male and female hair samples.  相似文献   

2.
Steroid 5-α reductase (5AR) is responsible for the reduction of steroids to 5-α reduced metabolites, such as the reduction of testosterone to 5-α dihydrotestosterone (DHT). A new adverse outcome pathway (AOP) for 5AR inhibition to reduce female reproduction in fish (AOP 289) is under development to clarify the antiestrogenic effects of 5AR inhibitors in female fish. A sensitive method for the DHT analysis using chemical derivatization and liquid chromatography–tandem mass spectrometry was developed. A cell-based 5AR inhibition assay that utilizes human cell lines, a transient overexpression system, and fish cell lines was developed. The measured IC50 values of two well-known 5AR inhibitors, finasteride and dutasteride, were comparable in the different systems. However, the IC50 of dutasteride in the fish cell lines was lower than that in the human cell lines. Finasteride showed a higher IC50 against the RTG-2 cell line. These results demonstrated that 5ARs inhibition could differ in terms of structural characteristics among species. The assay has high sensitivity and reproducibility and is suitable for the application in 5AR inhibition screening for various endocrine disruption chemicals (EDCs). Future studies will continue to evaluate the quantitative inhibition of 5AR by EDCs to compare the endocrine-disrupting pathway in different species.  相似文献   

3.
Factors influencing the steroid profile in doping control analysis   总被引:1,自引:0,他引:1  
Steroid profiling is one of the most versatile and informative screening tools for the detection of steroid abuse in sports drug testing. Concentrations and ratios of various endogenously produced steroidal hormones, their precursors and metabolites including testosterone (T), epitestosterone (E), dihydrotestosterone (DHT), androsterone (And), etiocholanolone (Etio), dehydroepiandrosterone (DHEA), 5alpha-androstane-3alpha,17beta-diol (Adiol), and 5beta-androstane-3alpha,17beta-diol (Bdiol) as well as androstenedione, 6alpha-OH-androstenedione, 5beta-androstane-3alpha,17alpha-diol (17-epi-Bdiol), 5alpha-androstane-3alpha,17alpha-diol (17-epi-Adiol), 3alpha,5-cyclo-5alpha-androstan-6beta-ol-17-one (3alpha,5-cyclo), 5alpha-androstanedione (Adion), and 5beta-androstanedione (Bdion) add up to a steroid profile that is highly sensitive to applications of endogenous as well as synthetic anabolic steroids, masking agents, and bacterial activity. Hence, the knowledge of factors that do influence the steroid profile pattern is a central aspect, and pharmaceutical (application of endogenous steroids and various pharmaceutical preparations), technical (hydrolysis, derivatization, matrix), and biological (bacterial activities, enzyme side activities) issues are reviewed.  相似文献   

4.
 This study concerns the detection of natural steroid hormones in hair of cattle. Estradiol (E2) and testosterone (T) were chosen as representatives of estrogens and androgens. In particular, the influence of age, sex and hair pigmentation on the steroid concentrations was investigated. Samples were obtained from numerous steers, cows, bulls, and female and male calves. The extraction procedure for E2 and T from hair comprised liquid-liquid and solid-phase extraction and was followed by an essential high-performance liquid chromatography (HPLC) step for further purification of the extracts. Final quantification was performed with specific enzyme immunoassays (EIA). Lower E2-concentrations were detected in the hair of some steers, cows, and bulls (approximately 1 ng/g), in several of these hair samples the concentrations of E2 were below the limit of detection. Testosterone was measured in the hair of steers (approximately 3 ng/g), cows (approximately 6 ng/g), and bulls (in average 15 ng/g). There was a significant difference in the testosterone concentrations of white (approximately 8 ng/g) and of black hair (approximately 33 ng/g) of bulls. In hair from all male and female calves, E2 and T were measured. The concentrations amounted approximately to 9 ng E2/g and 3 ng T/g for female calves and to 5 ng E2/g and 7 ng T/g for male calves. There was no significant influence of sex or hair colour on the steroid concentrations in hair of calves. The results suggest that the method is a powerful means to detect natural steroid hormones in hair of animal origin. Received: 2 August 1996/Revised: 30 August 1996/Accepted: 5 September 1996  相似文献   

5.
 This study concerns the detection of natural steroid hormones in hair of cattle. Estradiol (E2) and testosterone (T) were chosen as representatives of estrogens and androgens. In particular, the influence of age, sex and hair pigmentation on the steroid concentrations was investigated. Samples were obtained from numerous steers, cows, bulls, and female and male calves. The extraction procedure for E2 and T from hair comprised liquid-liquid and solid-phase extraction and was followed by an essential high-performance liquid chromatography (HPLC) step for further purification of the extracts. Final quantification was performed with specific enzyme immunoassays (EIA). Lower E2-concentrations were detected in the hair of some steers, cows, and bulls (approximately 1 ng/g), in several of these hair samples the concentrations of E2 were below the limit of detection. Testosterone was measured in the hair of steers (approximately 3 ng/g), cows (approximately 6 ng/g), and bulls (in average 15 ng/g). There was a significant difference in the testosterone concentrations of white (approximately 8 ng/g) and of black hair (approximately 33 ng/g) of bulls. In hair from all male and female calves, E2 and T were measured. The concentrations amounted approximately to 9 ng E2/g and 3 ng T/g for female calves and to 5 ng E2/g and 7 ng T/g for male calves. There was no significant influence of sex or hair colour on the steroid concentrations in hair of calves. The results suggest that the method is a powerful means to detect natural steroid hormones in hair of animal origin. Received: 2 August 1996/Revised: 30 August 1996/Accepted: 5 September 1996  相似文献   

6.
Detection of testosterone,nandrolone and precursors in horse hair   总被引:1,自引:0,他引:1  
Growing interest among several horse-breeder associations has initiated the development of a screening procedure to test for anabolic agents in hair, which has the advantage over blood and urine specimens of allowing long-term detection. An analytical method was established to monitor in tails or manes several anabolic substances available as veterinary medicines or as so-called nutritional supplements (clenbuterol, different esters or prohormones of nandrolone and testosterone). The analytical procedure to detect steroids in hair samples consists of the following steps: decontamination of the hair strand or segment with methanol/water (1:1), milling, extraction of the hair material in an ultrasonic bath using methanol, purification by liquid–liquid extraction (n-pentane/methanol, 25:1) and HPLC cleanup, derivatisation of the relevant LC fractions with MSTFA, and measurement using GC-MS/MS technique. The first objective of our study was the detection of exogenous nandrolone (nortestosterone, NT) in the horse hair; therefore nandrolone-associated compounds [nandrolone dodecanoate administered intramuscularly (i.m.) and a mixture of 4-estrenediol and 4-estrenedione, transdermal] were administered to four geldings. The highest concentrations of NT following i.m. treatment were measured after 10 days in a 2-cm hair segment (up to 18 pg/mg); NT was detectable for up to 120 days and in some cases up to 330 days in tail hair (limit of detection 0.3 pg/mg). Following transdermal application, nandrolone as well as the administered prohormones were identified in tail and mane until the latest sampling at 3 months. Furthermore, untreated stallions (128) were investigated to estimate the range of endogenous levels of NT and testosterone (T) in hair. Maximum values of 3 pg/mg (NT) and 1 pg/mg (T) were quantified originating from endogenous formation in the male horse. Additionally, a possible relationship between steroid concentrations in hair specimens and the age of stallions was appraised. NT and T were not detected in hair samples of control geldings. Following nandrolone treatment of geldings, highest values in hair exceeded the endogenous amount detected in untreated stallions. Therefore comparison of concentrations measured in control samples with the estimated endogenous levels could give a clue to exogenous application in cases of abnormally high amounts of NT or T. The possibility of the evaluation of threshold values is discussed as a means to verify an exogenous administration of NT and T in hair samples. Furthermore, the detection of a synthetic substance in hair, e. g. the parent steroid ester by itself, would be unequivocal proof of an exogenous origin of NT or T and the previous medication of the stallion.  相似文献   

7.
The pharmacological activities of 12 pregnane derivatives (4-15) were determined on gonadectomized male hamster flank organs and seminal vesicles as antiandrogens and as 5alpha-reductase inhibitors. The results from this study indicate that subcutaneous injection of testosterone for 3 d increased the diameter of the pigmented spot in the flank organs, whereas finasteride when injected with testosterone decreased the size of the spot significantly when steroids 4-15 were injected together with testosterone, the diameter of the flank organs of gonadectomized male hamsters, decreased significantly (p<0.005) compared to testosterone. Compound 11 was the most active steroid and reduced the diameter of the pigmented spot more than the other synthesized steroids or finasteride. Subcutaneous injections of testosterone to gonadectomized animals restore the seminal vesicle size lost upon castration. Injection of testosterone plus finasteride decreased significantly the weight of these glands (p<0.005). Steroids 5-15 when injected with testosterone decreased the weight of the seminal vesicles compared to testosterone. Finasteride is a good inhibitor of the conversion of testosterone to dihydrotestosterone (DHT) (low formation of DHT) measured as pmole of DHT/g of protein/h. Steroids 6-15 inhibited the conversion of testosterone to DHT as compared to testosterone however finasteride and 10 appeared to be the most effective compounds. Castration increases the protein content of the seminal vesicles (control) expressed as microg/mg of tissues. Testosterone tends to decrease it significantly, as did compounds 4, 5, 7, 9, and 15. We demonstrated that DHT as well as cyproterone acetate and steroids 5, 6, 8, 9, 11, and 14 at increasing non radioactive steroid concentration, inhibited the binding of [3H]DHT to cytosolic androgen receptor (AR), as indicated by its Ki values. However, 4, 7, 10, 12, and 13 did not have any inhibitory effect.  相似文献   

8.
Cytochrome P450 (CYP) 7B1 is a steroid cytochrome P450 7α‐hydroxylase that has been linked directly with bile salt synthesis and hereditary spastic paraplegia type 5 (SPG5). The enzyme provides the primary metabolic route for neurosteroids dehydroepiandrosterone (DHEA), cholesterol derivatives 25‐hydroxycholesterol (25‐HOChol), and other steroids such as 5α‐androstane‐3β,17β‐diol (anediol), and 5α‐androstene‐3β,17β‐diol (enediol). A series of investigations including homology modeling, molecular dynamics (MD), and automatic docking, combined with the results of previous experimental site‐directed mutagenesis studies and access channels analysis, have identified the structural features relevant to the substrate selectivity of CYP7B1. The results clearly identify the dominant access channels and critical residues responsible for ligand binding. Both binding free energy analysis and total interaction energy analysis are consistent with the experimental conclusion that 25‐HOChol is the best substrate. According to 20 ns MD simulations, the Phe cluster residues that lie above the active site, particularly Phe489, are proposed to merge the active site with the adjacent channel to the surface and accommodate substrate binding in a reasonable orientation. The investigation of CYP7B1–substrate binding modes provides detailed insights into the poorly understood structural features of human CYP7B1 at the atomic level, and will be valuable information for drug development and protein engineering.  相似文献   

9.
The pharmacological activity of several 16-bromosubstituted trienediones 4 and 5, 16-methyl substituted dienediones 6 and 7 and the 16-methyl substituted trienedione 8 was determined on gonadectomized hamster seminal vesicles by measuring the in vitro conversion of testosterone (T) to dihydrotestosterone (DHT) as 5alpha-reductase inhibitors and also the ability of these steroids to bind to the androgen receptor. Steroids 6 and 7 when injected together with T decreased the weight of the seminal vesicles thus showing an antiandrogenic effect. Compounds 5 and 6 reduced substantially the conversion of T to DHT and therefore can be considered good inhibitors for the enzyme 5alpha-reductase; however both steroids failed to form a complex with the androgen receptor. On the other hand compound 7 which showed a very small inhibitory activity for the enzyme 5alpha-reductase, exhibited a very high affinity for the androgen receptor and thus can be considered an effective antiandrogen. This compound also reduced substantially the weight of the seminal vesicles. Steroids 4 and 8 did not reduce the weight of the seminal vesicles and exhibited a low affinity for the androgen receptor; 8 showed a weak 5alpha-reductase inhibitory activity, whereas 4 exhibited a weak androgenic effect.  相似文献   

10.
Summary An analytical method to detect the illegal application of the anabolic steroid methyltestosterone (MT) in cattle by hair analysis was developed. The time course of the incorporation of this orally active xenobiotic steroid into growing hair and the duration of its possible detection by hair analysis were measured. Female veal calves were fed with 35 μg MT per kg body weight, twice daily, for 10 days. Before, during and after the treatment, hair samples were obtained and analyzed for MT residues. An appropriate method to extract MT from hair was developed. The extraction procedure consisted of liquid-liquid and solid-phase extraction and was followed by an essential high performance liquid chromatography (HPLC) step for further purification of the extracts. Final quantitfication was done with a specific enzyme immunoassay (EIA). MT residues could be detected in hair from day 4 (approximately 5 ng MT/g hair) of the experiment up to day 94 (approaximately 0.5 ng MT/g). Our results suggest that hair analysis may be a powerful means to detect and track the illegal use of anabolic steroids. Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996  相似文献   

11.
The abuse of synthetic esters of natural steroids such as testosterone and estradiol in cattle fattening and sports is hard to detect via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. An interesting alternative can be provided by the analysis of the administered synthetic steroids themselves, i.e., the analysis of intact steroid esters in hair by liquid chromatography tandem mass spectrometry (LC/MS/MS). However, retrospective estimation of the application date following a non-compliant finding is hindered by the complexity of the kinetics of the incorporation of steroid esters in hair. In this study, the incorporation of intact steroid esters in hair following pour-on treatment has been studied and critically compared with results from intramuscular treatment. To this end animals were pour-on treated with a hormone cocktail containing testosterone cypionate, testosterone decanoate and estradiol benzoate in different carriers. The animals were either treated using injection and pour-on application once or three times having 1 week between treatments using injection and pour-on application. Animals were slaughtered from 10–12 weeks after the last treatment. Both hair and blood plasma samples were collected and analysed by LC/MS/MS. From the results, it is concluded that after single treatment the levels of steroid esters in hair drop to CCβ levels (5–20 μg/kg) after 5–7 weeks. When treatment is repeated two times, the CCβ levels are reached after 9–11 weeks. Furthermore, in plasma, no steroid esters were detected; not even at the low microgramme per litre level but—in contrast with the pour-on application—after i.m. injection, significant increase of 17β-testosterone and 17β-estradiol were observed. These observations suggest that transport of steroid esters after pour-on application is not only performed by blood but also by alternative fluids in the animal so probably the steroid esters are already hydrolysed and epimerized before entering the blood.  相似文献   

12.
Abnormalities in steroid hormones are responsible for the development and prevention of endocrine diseases. Due to their biochemical roles in endocrine system, the quantitative evaluation of steroid hormones is needed to elucidate altered expression of steroids. Gas chromatographic-mass spectrometric (GC-MS) profiling of 70 urinary steroids, containing 22 androgens, 18 estrogens, 15 corticoids, 13 progestins, and 2 sterols, were validated and its quantitative data were visualized using hierarchically clustered heat maps to allow “steroid signatures”. The devised method provided a good linearity (r 2 > 0.994) with the exception of cholesterol (r 2 = 0.983). Precisions (% CV) and accuracies (% bias) ranged from 0.9% to 11.2% and from 92% to 119%, respectively, for most steroids tested. To evaluate metabolic changes, this method was applied to urine samples obtained from 59 patients with benign prostatic hyperplasia (BPH) versus 41 healthy male subjects. Altered concentrations of urinary steroids found and heat maps produced during this 70-compound study showed also differences between the ratios of steroid precursors and their metabolites (representing enzyme activity). Heat maps showed that oxidoreductases clustered (5β-reductase, 3β-HSD, 3β-HSD, and 17β-HSD, except for 20β-HSD). These results support that data transformation is valid, since 5β-reductase is a marker of BPH and 17β-HSD is positively expressed in prostate cells. Multitargeted profiling analysis of steroids generated quantitative results that help to explain correlations between enzyme activities. The data transformation and visualization described may to be found in the integration with the mining biomarkers of hormone-dependent diseases.  相似文献   

13.
The pharmacological activity of eight pregnane derivatives 17-alpha acetoxyprogesterone 9, 17-alpha acetoxy-4, 5-epoxypregnan-3, 20-dione 10, 17-alpha acetoxy-4-chloro-4-pregnene-3, 20-dione 11, 17-alpha acetoxy-4-bromo-4-pregnene-3, 20-dione 12, 17-alpha hydroxy-4-bromo-4-pregnene-3, 20-dione 13, 4-chloro-17-alpha hydroxy-4-pregnene-3, 20-dione 14, 17-alpha benzoyloxy-4-bromo-4-pregnene-3, 20-dione 15 and 17-alpha benzoyloxy-4-chloro-4-pregnene-3, 20-dione 16 was determined. These compounds were evaluated as antiandrogens on gonadectomized hamster seminal vesicles. The pharmacological data in this study indicate that compounds 15 and 16 having a C-17 benzoyloxy moiety showed the highest antiandrogenic activity as measured by the reduction of the weight of the seminal vesicles, followed by the steroids 11 and 12 (17-alpha acetoxy group). The free alcohols 13 and 14 exhibited a lower antiandrogenic activity. Apparently, the ester moiety at C-17 is a necessary requirement for the presence of high antiandrogenic activity. Shows the inhibitory effect on the conversion of testosterone (T) to DHT, of the above described steroids as measured by the amount of produced DHT 2 expressed as pmoles of DHT/g of protein/h. Steroids 11, 12 and 16 showed a much higher inhibitory activity on the conversion of testosterone (T) to dihydrotestosterone (DHT) than presently used finasteride 3.  相似文献   

14.
The development and application of a combined gas chromatography/thermal conversion/isotope ratio mass spectrometry (GC/TC/IRMS) method for D/H ratio determination of endogenous urinary steroids are presented. The key element in sample preparation was the consecutive cleanup with high‐performance liquid chromatography of initially native and subsequently acetylated steroids. This strategy enabled sufficient cleanup off all target analytes for determination of their respective D/H values. Ten steroids (11β‐hydroxyandrosterone, 5α‐androst‐16‐en‐3α‐ol, pregnanediol, androsterone, etiocholanolone, testosterone, epitestosterone, 5α‐androstan‐3α,17β‐diol, 5β‐androstan‐3α,17β‐diol and dehydroepiandrosterone) were measured from a single urine specimen. Depending on the biological background, the determination limit for all steroids ranged from 10 to 15 ng/mL for a 20 mL specimen. The method was validated by application of linear mixing models on each steroid and covered repeatability and reproducibility. The specificity of the procedure was ensured by gas chromatography/mass spectrometry (GC/MS) analysis of the sample using equivalent chromatographic conditions to those employed in the GC/TC/IRMS measurement. Within the sample preparation, no isotopic fractionation was observed, and no amount‐dependent shift of the D/H ratios during the measurement was noticed. Possible memory effects occurring during IRMS measurements were corrected by applying a simple rule of proportion. In order to determine the naturally occurring D/H ratios of all implemented steroids, a population of 18 male subjects was analyzed. Relevant mean Δ values among selected steroids were calculated which allowed us to study the metabolic pathways and production sites of all the implemented steroids with additional consideration of the corresponding 13C/12C ratios. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

15.
The detection of steroid residues in hair is a powerful strategy to demonstrate long-term administration of these growth promoters in meat production animals. A fast and reliable method was developed for monitoring anabolic steroids and their esters in hair. A 100 mg hair sample was converted into powder and extracted at 50 °C with methanol (sebum fraction). The remaining hair was digested with 1 M NaOH for further extraction of bound steroids. The two fractions were separately purified onto an aminopropyle solid-phase extraction column and onto a silica SPE cartridge. Steroids were detected either by gas chromatography-tandem mass spectrometry after silylation using N-methyl-N-(trimethylsilyl)-trifluoroacetamide/trimethyliodosilane/dithiothreitol or liquid chromatography-tandem mass spectrometry. This method was applied to hair samples collected over a three months period after treatment of three cows respectively with 17α-methyltestosterone, medroxyprogesterone acetate and 17β-estradiol-3-benzoate. The fixation kinetic into hair of the three steroids have been deeply examined and discussed; relation in-between concentration and distance from the injection site, influence of hair colour and sample treatment consequences have been discussed.  相似文献   

16.
Testosterone (T) and 5alpha-dihydrotestosterone (DHT) are now referred to not only as androgenic steroid hormones, but also as neuroactive steroids, because they elicit anesthetic and anxiolytic effects. Methods using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) coupled with derivatization are developed and validated to examine rat brain and serum levels of T and DHT and their stress-induced changes. The steroids are extracted with methanol-acetic acid from the brain tissue or serum, purified using solid-phase extraction cartridges, derivatized with a permanently charged reagent, 2-hydrazino-1-methylpyridine, and subjected to LC-MS-MS. [19,19,19-(2)H3]-T is used as the internal standard. The intra- and inter-assay coefficients of variation are below 10.0%, and the analytical recoveries are 98.1-103.0%. The developed methods are applied to the animal study and it was found that a fair amount of DHT is continuously and locally synthesized in the brain, and its level is not changed by the immobilization stress and depends on the brain T level.  相似文献   

17.
Autocrine and paracrine factors play key roles in the process of Androgenetic alopecia (AGA), which are secreted by balding dermal papilla cells (DPCs) after dihydrotestosterone (DHT) induction. Camellia seed cake is an oriental oil extraction byproduct, and its extract has been traditionally used to wash hair in China. This study elucidated the hair growth-promoting effects of Camellia seed cake extract (CSCE) in DHT-treated cultured DPCs and its underlying mechanisms. The effect of CSCE on cell viability and release of inflammatory factors IL-6 and IL-1α was performed on human dermal papilla cells (DPCs) incubated with DHT. Relative expression of bax, bcl-2, p53, androgen receptor (AR) and 5α- reductase type II (SRD5A2) was determined by PCR. Senescence-associated was examined by β-galactosidase (SA-β-Gal) assays. CSCE restored DHT-induced cell damage in a dose-dependent manner, and effectively reduced the production of IL-6 and IL-1α in DHT-treated DPCs. CSCE exhibited an anti-apoptotic effect, which increased the expression of bcl-2, and decreased the expressions of bax and p53 in DHT-incubated DPCs. CSCE also showed an anti-androgenic effect reversing the increase in AR and SRD5A2 expressions in DPCs driven by DHT incubation. In addition, CSCE inhibited the β-galactosidase enzyme activity and slowed down the cell senescence of DPCs which is crucial for AGA progression. In this study, we found that CSCE may have the potential to prevent and alleviate AGA by abrogating the effect of DHT in cultured DPCs.  相似文献   

18.
Hormone and veterinary drug screening and forensics can benefit from the recent developments in desorption electrospray ionization (DESI) mass spectrometry (MS). In this work the feasibility of DESI application for the rapid screening of intact esters of anabolic steroids in bovine hair has been studied. Using a linear ion trap both full scan and data-dependent collision induced dissociation MS(n) spectra were acquired in minutes for testosterone cypionate, testosterone decanoate and estradiol benzoate standard solutions deposited on a glass or PTFE surface. However direct analysis of incurred hair failed due to inefficient desorption ionization and the minute quantities of steroid esters present. Therefore a simplified ultrasonic liquid extraction procedure was developed, allowing rapid DESI analysis of a few microliters of the concentrate and a total analysis time of 2-4h per batch instead of 3 days. The potential of this DESI approach is clearly demonstrated by MS(3) data from hair samples incurred with high levels (300-800 μg kg(-1)) of steroid esters, levels which do occur in samples from controlled- and illegally treated animals. For much lower levels state-of-the-art ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) screening methods remain the method of choice and might benefit from the proposed simplified extraction as well.  相似文献   

19.
Carisoprodol (CSP) is a musculoskeletal relaxant whose active metabolite is meprobamate (MPB). This drug has recently been noticed to be abused as an inexpensive alternative to illicit drugs in Korea. A method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) was developed for the determination of CSP and MPB in human hair. Hair samples (30 mg) were washed with distilled water and acetone, cut into small fragments (<1 mm), incubated in 1.0 M HCl overnight at 50 degrees C, and then adjusted to pH 6.5. The drugs were extracted from the resulting hydrolyzed solutions using a SPE column. The eluents were evaporated to dryness, then derivatized using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS) at 120 degrees C for 30 min. The derivatized extract (1 microL) was injected into the GC/MS system. Recoveries were in the range of 91.5-93.1% for CSP and 85.5-93.0% for MPB. The linear ranges were 0.5-10.0 ng/mg for both CSP and MPB with good correlation coefficients (r(2) = 0.995). The intra-day precision and accuracy ranged from 1.5 to 9.3% and -17.5 to 3.6%, respectively, and the inter-day precision and accuracy ranged from 3.9 to 6.2% and -15.0 to -3.9%, respectively. The limits of detection for CSP and MPB were 0.13 and 0.12 ng/mg, respectively. The applicability of the method was proven by analyzing a hair sample from an authentic abuser. Copyright (c) 2005 John Wiley & Sons, Ltd.  相似文献   

20.
Measurement of steroid esters in bovine hair samples, using sensitive liquid chromatography-tandem mass spectrometry (LC–MS/MS), provides a powerful tool for identifying animals treated illicitly with growth promoters. The successful application of such testing requires appropriate sampling of hair from treated animals. This paper describes the results of hair analysis by LC–MS/MS for two animal studies in which animals were treated with estradiol-3-benzoate and nortestosterone decanoate. The results from the first animal study indicate that animals treated with these anabolic steroids may not always be identified from analysis of hair samples; positive test results occur sporadically and only for some of the treated animals. The results from the second animal study identify conditions attaching to positive hair samples, such as, that concentrations of steroid esters in hair are related to distance of sampling from point of injection and to time post-treatment, that concentrations of steroid esters in hair are related to dose given to the animal but that this relationship may vary over time post-treatment, and that steroid esters may be measured in regrowth hair taken some weeks after treatment. Steroid esters are determined along the length of the hair, confirming that accumulation of steroid esters into hair occurs from various sources, including blood, sweat and sebum. The reported research provides some useful insights into the mechanisms governing the persistence of steroid esters in bovine hair following illicit treatment with growth promoters.  相似文献   

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