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1.
Poisonings with toxic plants may occur after abuse, intentional or accidental ingestion of plants. For diagnosis of such poisonings, multianalyte procedures were developed for detection and validated quantification of the toxic alkaloids aconitine, atropine, colchicine, coniine, cytisine, nicotine and its metabolite cotinine, physostigmine, and scopolamine in plasma using LC-APCI-MS and LC-ESI-MS/MS. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a C8 base select separation column and gradient elution (acetonitrile/ammonium formate, pH 3.5). Calibration curves were used for quantification with cotinine-d(3), benzoylecgonine-d(3), and trimipramine-d(3) as internal standards. The method was validated according to international guidelines. Both assays were selective for the tested compounds. No instability was observed after repeated freezing and thawing or in processed samples. The assays were linear for coniine, cytisine, nicotine and its metabolite cotinine, from 50 to 1000 ng/ml using LC-APCI-MS and 1 to 1000 ng/ml using LC-ESI-MS/MS, respectively, and for aconitine, atropine, colchicine, physostigmine, and scopolamine from 5 to 100 ng/ml for LC-APCI-MS and 0.1 to 100 ng/ml for LC-ESI-MS/MS, respectively. Accuracy ranged from -38.6 to 14.0%, repeatability from 2.5 to 13.5%, and intermediate precision from 4.8 to 13.5% using LC-APCI-MS and from -38.3 to 8.3% for accuracy, from 3.5 to 13.8%, for repeatability, and from 4.3 to 14.7% for intermediate precision using LC-ESI-MS/MS. The lower limit of quantification was fixed at the lowest calibrator in the linearity experiments. With the exception of the greater sensitivity and higher identification power, LC-ESI-MS/MS had no major advantages over LC-APCI-MS. Both presented assays were applicable for sensitive detection of all studied analytes and for accurate and precise quantification, with the exception of the rather volatile nicotine. The applicability of the assays was demonstrated by analysis of plasma samples from suspected poisoning cases.  相似文献   

2.
A method for the quantification of progesterone (PROG) in human saliva using liquid chromatography–electrospray ionization–tandem mass spectrometry (LC‐ESI‐MS/MS) has been developed and validated. The saliva was deproteinized with acetonitrile, purified using a Strata™‐X cartridge, and subjected to LC‐ESI‐MS/MS. Quantification was based on selected reaction monitoring, and deuterated PROG was used as the internal standard. This method allowed the reproducible (intra‐ and inter‐assay relative standard deviations, <2.2%) and accurate (analytical recovery, 96.6–99.7%) quantification of the salivary PROG using a 400 μL sample, and the limit of quantification was 12.5 pg/mL. The developed method enabled detection of the variation in the salivary PROG concentrations of healthy volunteers during the menstrual cycle and measurement of the salivary concentrations of pregnant women. The method is expected to be an alternative to the blood PROG monitoring in clinical examinations, because saliva collection is easy, non‐invasive and repeatable. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

3.
The development and validation of liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) methods that enable the quantification of neuroactive androgens, androsterone (5alpha-androstan-3alpha-ol-17-one, 3alpha,5alpha-A) and 5alpha-androstane-3alpha,17beta-diol (3alpha,5alpha-Adiol), in the rat brain and serum are presented. The androgens were extracted with methanol-acetic acid, purified using solid-phase extraction cartridges, derivatized with an ESI-active reagent, isonicotinoyl azide (INA), and then subjected to LC-ESI-MS/MS. The quantifications were based on selected reaction monitoring mode using the characteristic transitions of the INA derivatives. The methods allowed the reproducible and accurate quantification of the brain and serum neuroactive androgens using a 100 mg or 100 microL sample; the intra- and inter-assay relative standard deviations were below 3.6%, and the percentage accuracy values were 97.1-103.7% for both androgens. The animal study using the methods suggests that most of 3alpha,5alpha-Adiol found in the brain is derived from the periphery, while 3alpha,5alpha-A is not only transported from the periphery into the brain, but also synthesized in the brain by the oxidation of 3alpha,5alpha-Adiol. The androgens in the rats intraperitoneally administered finasteride, a 5alpha-reductatse inhibitor, were also measured; this treatment significantly reduced the brain 3alpha,5alpha-A and 3alpha,5alpha-Adiol levels and increased only the brain level of androstenedione, the precursor of 3alpha,5alpha-A.  相似文献   

4.
The glucosinolate profile of black radish (Raphanus sativus L. niger) based dietary supplements has been investigated by HPLC-PDA, LC-ESI-MS/MS and LC-APCI-MS/MS systems. Optimization of the MS/MS parameters and LC conditions was performed using sinigrin reference standard and rapeseed certified reference material (BC190) respectively. An LC-ESI-MS/MS system was used to detect (screen) and identify the naturally occurring intact glucosinolates (GLs). The intact GLs identified were then desulfated and quantified on an HPLC-PDA system as desulfo-glucosinolates (DS-GLs). Prior to quantification, the DS-GLs were identified using an APCI-MS/MS. The HPLC-PDA method performance criteria were evaluated using glucotropaeolin potassium salt. The validated method was applied for the analysis of six dietary supplements. In total, six glucosinolates were identified and quantified in the dietary supplements; glucoraphasatin (0.2-0.48 mg/g), glucosisaustricin (0.37-0.91 mg/g), glucoraphenin (0.84-1.27 mg/g), glucoputrajivin (0.14-0.28 mg/g), glucosisymbrin (0.70-0.99 mg/g) and gluconasturtiin (0.06-0.12 mg/g). Glucoraphenin was the most abundant glucosinolate in all samples.  相似文献   

5.
Aripiprazole is an important antipsychotic drug. A simple, sensitive and rapid ultra‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC‐ESI‐MS/MS) method was developed and validated for the simultaneous quantification of this compound in rat plasma and brain homogenate. The analyte was extracted from rat plasma and brain homogenate using a weak cation exchange mixed‐mode resin‐based solid phase extraction. The compound was separated on an Agilent Eclipse Plus C18 (2.1 × 50 mm, 1.8 µm) column using a mobile phase of (A) 0.1% formic acid aqueous and (B) acetonitrile with gradient elution. The analyte was detected in positive ion mode using multiple reaction monitoring. The method was validated and the specificity, linearity, limit of quantitation (LOQ), precision, accuracy, recoveries and stability were determined. The LOQ was 0.5 ng/mL for aripiprazole in plasma and 1.5 ng/g in brain tissue. The MS response was linear over the concentration range 0.5–100 ng/mL for aripiprazole in plasma and 1.5–300 ng/g in brain tissue. The precision and accuracy for intra‐day and inter‐day were better than 14%. The relative and absolute recoveries were above 72% and the matrix effects were low. This validated method was successfully used to quantify the rat plasma and brain tissue concentrations of the analyte following chronic treatment with aripiprazole. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

6.
A method employing silicone oil density centrifugation, solid-phase extraction (SPE) cleanup, and LC-ESI-MS/MS analysis was developed for the rapid, selective, sensitive, and quantitative detection of an intracellular pool of short organic acid-CoA esters in actinomycetes. The detection limit was determined to be approximately 0.8 pmol (1.2 ng/ml) for each standard CoA-ester analyzed by the present LC-ESI-MS/MS method. A selected ion chromatogram for a typical fragment ion (m/z 428) specific to CoA-esters enabled the detection of eight intracellular CoA-esters involved in both primary and secondary metabolisms. The application of this method to bacterial metabolomic study is demonstrated by the profiling of the intracellular CoA-ester pools in the wild-type Streptomyces venezuelae strain producing polyketide antibiotics (methymycin and pikromycin), a polyketide synthase (PKS)-deleted S. venezuelae mutant, and a S. venezuelae mutant expressing the heterologous PKS genes. By quantifying the individual CoA-esterlevel in three different genotypes of the S. venezuela e strain, further insight could be gained into the role of CoA-estersin polyketide biosynthesis. This analytical approach can be extended to the quantification of the size and composition of in vivo CoA-ester pools in various microbes, and can provide a detailed understanding of the relationship between the in vivo CoA-ester pool and the production of pharmaceutically important polyketides.  相似文献   

7.
A sensitive assay method was developed for a parallel, rapid and precise determination of dopamine and its metabolites, homovanillic acid, 3-methoxytyramine and 3,4-dihydroxyphenylacetic acid, from brain microdialysates. The method consisted of a pre-treatment step, freeze-drying (lyophilization), to concentrate dopamine and its metabolites from the microdialysates, and a detection step using liquid chromatography combined with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). In particular, the reaction monitoring mode was selected for its extremely high degree of selectivity and the stable-isotope-dilution assay for its high precision of quantification. The developed method was characterized by the following parameters: the precision of the developed method was determined as ≥88.6% for dopamine, ≥89.9% for homovanillic acid, ≥86.1% for 3-methoxytyramine and ≥88.1% for 3,4-dihydroxyphenylacetic acid; the mean accuracy was determined as ≥88.2% for dopamine, ≥88.3% for homovanillic acid, ≥85.9% for 3-methoxytyramine and ≥88.6% for 3,4-dihydroxyphenylacetic acid. The developed method was compared to (1) other combinations of pre-treatment methods (solid phase extraction and nitrogen stripping) with LC-MS and (2) another detection method, liquid chromatography, with electrochemical detection. The novel developed method using combination of lyophilization with LC-ESI-MS/MS was tested on real samples obtained from the nucleus accumbens of rat pups after an acute methamphetamine administration. It was proven that the developed assay could be applied to both a simultaneous analysis of all four substrates (dopamine, homovanillic acid, 3-methoxytyramine and 3,4-dihydroxyphenylacetic acid) in microdialysis samples acquired from the rat brain and the monitoring of their slight concentration changes on a picogram level over time following methamphetamine stimulus.  相似文献   

8.
The surfactants perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and derivatives of the latter have emerged as globally distributed persistent environmental contaminants. Methods for their reliable quantitative determination at ppt-levels (ng/L) are needed in order to detect their main sources, to elucidate their environmental fate, and to identify potential sinks. The common method for water analysis involves preconcentration by SPE followed by LC coupled to ESI MS/MS (LC-ESI-MS/ MS). All sample preparation steps must be carefully optimized in order to arrive at reliable quantitative data. Two major aspects are important: (i) during SPE, contaminations may arise from materials containing traces of PFOA/S; (ii) during LC-ESI-MS/ MS, ionization yields are suppressed by matrix components and depend upon the analyte concentrations in the extracts. The levels of PFOA/S in the river Roter Main near Bayreuth have been determined using the optimized method.  相似文献   

9.
A rapid, sensitive and specific high-performance liquid chromatography/electrospray ionization mass spectrometric (LC-ESI-MS) method was developed and validated for the quantification of madecassoside, a major active constituent of Centella asiatica (L.) Urb. herbs, in rat plasma. With paeoniflorin as an internal standard (IS), a simple liquid-liquid extraction process was employed for the plasma sample preparation. Chromatographic separation was achieved within 6 min on a Shim-pack CLC-ODS column using acetonitrile and water (60:40, v/v) containing 0.1% (v/v) formic acid as the mobile phase. The detection was performed by MS with electrospray ionization interface in negative selected ion monitoring (SIM) mode. The linear range was 11-5500 ng/mL with the square regression coefficient (r(2) ) of 0.9995. The lower limit of quantification was 11 ng/mL. The intra- and inter- day precision ranged from 4.99 to 9.03%, and the accuracy was between 95.82 and 111.80%. The average recoveries of madecassoside and IS from spiked plasma samples were >92%. The developed method was successfully applied to the pharmacokinetic study of madecassoside in rats after an oral administration.  相似文献   

10.
Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIa, an important lipophilic component contained in Salvia miltiorrhizae. A simple, sensitive and robust quantification method for STS based on LC-ESI-MS/MS was developed and validated, and has been successfully applied to the pharmacokinetic study. Liquid-liquid extraction was used for extracting STS from biological samples, with a satisfactory recovery exceeding 75% at all test concentrations. Isocratic mobile phase consisted of 75% acetonitrile and 25% water containing 0.005% ammonia acetate (pH 3). Good retention and baseline separation for STS and the selected internal standard, diclofenac sodium, were obtained on a Shim-pack VP-ODS analytical column under this condition. The method was linear in the concentration range of 1-500 ng/mL. The intra- and inter-day precisions (RSD%) were within 9.0%. The deviation of the assay accuracies was within +/-10.0%. STS was proved to be stable during all sample storing, preparation and analytic procedures. With a lower limit of quantitation at 1 ng/mL, this method has been proved to be sensitive enough for the pharmacokinetic study of STS. The plasma profile of STS followed a single intravenous dosing was well fitted to a three compartmental model.  相似文献   

11.
A novel LC‐MS/MS method was developed for the quantification of vildagliptin in an aqueous matrix. The method was successfully validated, meeting all the requisites of US Food and Drug Administration guide for a bioanalytical method. The developed method presented a limit of quantification of 10 ng/mL and the range of concentration achieved was 10–1875 ng/mL. The injection volume necessary was only 10 μL, and retention time was 4.60 min. The mobile phase employed was methanol–ammonium acetate 5 mm (95:5). The stability of the drug was evaluated in the different conditions through which the samples passed. A pharmacokinetic experiment was conducted with diabetic male Wistar rats, and the concentration of drug in liver was evaluated through a microdialysis technique. The perfusion fluid employed was ultrapure water. The dose administrated was 50 mg/kg and the method allowed the quantification of vildagliptin for more than three half lives, successfully characterizing the pharmacokinetic profile when the developed method was applied. This is the first report on the tissue pharmacokinetics of a DPP‐4 inhibitor and could contribute to drug dosage optimization in the future. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

12.
The herbal stimulants Ephedra species, Catha edulis (khat), and Lophophora williamsii (peyote) have been abused for a long time. In recent years, the herbal drug market has grown owing to publicity on the Internet. Some ingredients of these plants are also ingredients of cold remedies. The aim of the presented study is to develop a multianalyte procedure for detection and validated quantification of the phenalkylamines ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine, methylpseudoephedrine, cathinone, mescaline, synephrine (oxedrine), and methcathinone in plasma. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a strong cation exchange separation column and gradient elution. They were detected using a Q-Trap LC-ESI-MS/MS system (MRM mode). Calibration curves were used for quantification using norephedrine-d3, ephedrine-d3, and mescaline-d9 as internal standards. The method was validated according to international guidelines. The assay was selective for the tested compounds. It was linear from 10 to 1000 ng/ml for all analytes. The recoveries were generally higher than 70%. Accuracy ranged from - 0.8 to 20.0%, repeatability from 2.5 to 12.3%, and intermediate precision from 4.6 to 20.0%. The lower limit of quantification was 10 ng/ml for all analytes. No instability was observed after repeated freezing and thawing or in processed samples. The applicability of the assay was tested by analysis of authentic plasma samples after ingestion of different cold medications containing ephedrine or pseudoephedrine, and after ingestion of an aqueous extract of Herba Ephedra. After ingestion of the cold medications, only the corresponding single alkaloids were detected in human plasma, whereas after ingestion of the herb extract, all six ephedrines contained in the plant were detected. The presented LC-MS/MS assay was found applicable for sensitive detection and accurate and precise quantification of all studied analytes in plasma.  相似文献   

13.
A specific and sensitive multi-method based on liquid chromatography–tandem mass spectrometry using atmospheric pressure chemical ionization (LC–APCI–MS/MS) has been developed for the determination of 20 anabolic steroids in muscle tissue (diethylstilbestrol, β-estradiol, ethynylestradiol, α/β-boldenone, α/β-nortestosterone, methyltestosterone, β-trenbolone, triamcinolone acetonide, dexamethasone, flumethasone, α/β-zearalenol, α/β-zearalanol, zearalenone, melengestrol acetate, megestrol acetate and medroxyprogesterone acetate). The procedure involved hydrolysis, extraction with tert-butyl methyl ether, defattening and final clean-up with solid phase extraction (SPE) on Oasis HLB and Amino cartridges. The analytes were analyzed by reversed-phase LC–MS/MS, in positive and negative multiple reaction monitoring (MRM) mode, acquiring two diagnostic product ions from each of the chosen precursor ions for the unambiguous confirmation of the hormones. The method was validated at the validation level of 0.5 ng/g. The accuracy and precision of the method were satisfactory. The decision limits CCα ranged from 0.03 to 0.14 ng/g while the detection capabilities CCβ ranged from 0.05 to 0.24 ng/g. The developed method is sensitive and useful for detection, quantification and confirmation of these anabolic steroids in muscle tissue and can be used for residue control programs.  相似文献   

14.
A method has been developed for the simultaneous quantification of metformin (I) and glipizide (II) in human plasma. It is based on high-performance liquid chromatography with electrospray ionization tandem mass (LC-ESI-MS/MS) spectrometric detection in positive ionization mode. Phenformin (III) and gliclazide (IV) were used as internal standards for I and II, respectively. The MS/MS detection was performed in multiple reaction monitoring (MRM) mode. The precursor-product ion combinations of m/z 130 --> 71, 446 --> 321, 206 --> 60 and 324 --> 127 were used to quantify I, II, III and IV, respectively. This method was validated in the concentration ranges of 0.02-4 microg/mL for I and 0.004-0.8 microg/mL for II. It was utilized to support a clinical pharmacokinetic study after single dose oral administration of a combination of I and II.  相似文献   

15.
A sensitive liquid chromatography-electrospray ionization-tandem mass spectrometric (LC-ESI-MS/MS) method for the determination of the rat brain 5alpha-androstane-3alpha,17beta-diol (3alpha,5alpha-Adiol) has been developed and validated. The brain extract was purified using solid-phase extraction cartridges, derivatized with isonicotinoyl azide, and subjected to LC-MS/MS. The method was accurate and reproducible, and the limit of quantitation was 0.1 ng/g tissue when a 100-mg tissue sample was used. The change in the brain 3alpha,5alpha-Adiol level by immobilization stress was also analyzed using the developed method.  相似文献   

16.
A very accurate and selective LC‐MS/MS method was developed and validated for the quantification of 2′‐C‐modified nucleoside triphosphate in liver tissue samples. An efficient pretreatment procedure of liver tissue samples was developed, using a fully automated SPE procedure with 96‐well SPE plate (weak anion exchange sorbent, 30 mg). Nucleotide hydrophilic interaction chromatography has been performed on an aminopropyl column (100 mm×2.0 mm, 3 μm) using a gradient mixture of ACN and ACN/water (5:95 v/v) with 20 mM ammonium acetate at pH 9.45 as mobile phase at 300 μL/min flow rate. The 2′‐C‐modified nucleoside triphosphate was detected in the negative ESI mode in multiple reaction monitoring (MRM) mode. Calibration curve was linear over the 0.05–50 μM concentration range. Satisfying results, confirming the high reliability of the established LC‐MS/MS method, were obtained for intraday precision (CV = 2.5–9.1%) and accuracy (92.6–94.8%) and interday precision (CV = 9.6–11.5%) and accuracy (94.4–102.4%) as well as for recovery (82.0–112.6%) and selectivity. The method has been successfully applied for pharmacokinetic studies of 2′‐C‐methyl‐cytidine‐triphosphate in liver tissue samples.  相似文献   

17.
Tigecycline (TIG), a derivative of minocycline, is the first in the novel class of glycylcyclines and is currently indicated for the treatment of complicated skin structure and intra‐abdominal infections. A selective, accurate and reversed‐phase high‐performance liquid chromatography‐tandem mass spectrometry (HPLC‐MS/MS) method was developed for the determination of TIG in rat brain tissues. Sample preparation was based on protein precipitation and solid phase extraction using Supel‐Select HLB (30 mg/1 mL) cartridges. The samples were separated on a YMC Triart C18 column (150 mm x 3.0 mm. 3.0 µm) using gradient elution. Positive electrospray ionization (ESI+) was used for the detection mechanism with the multiple reaction monitoring (MRM) mode. The method was validated over the concentration range of 150–1200 ng/mL for rat brain tissue. The precision and accuracy for all brain analyses were within the acceptable limit. The mean extraction recovery in rat brain was 83.6%. This validated method was successfully applied to a pharmacokinetic study in female Sprague Dawley rats, which were given a dose of 25 mg/kg TIG intraperitoneally at various time‐points. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

18.
Neurotransmitters and their metabolites in central nervous system were known to play a significant role in sedation and hypnosis. A rapid and sensitive UFLC‐MS/MS method for simultaneous determination of serotonin, 5‐hydroxyindole acetic acid (5‐HIAA), tryptophan (Try), dopamine (DA), norepinephrine (NE), γ‐aminobutyric acid (GABA), glutamic acid (Glu) and acetylcholine (Ach) in rat brain without derivatization, ion‐pairing reagent or pre‐concentration was developed. Analytes and IS were separated on a Inertsil ODS‐EP column (150 mm × 4.6 mm, 5 µm particles) and analyzed in a single chromatographic run in less than 9.0 min, using gradient elution with the mobile phase consisting of methanol and 0.01% acetic acid in water at a flow rate of 1.2 ml min?1. The detection of the analytes was performed on 4000Q UFLC‐MS/MS system with turbo ion spray source in positive ion and multiple reaction monitoring mode. The developed method provided excellent linear calibration curves for the assay of analytes (R2 ≥ 0.9915). Limits of quantification were in the range of 1.0 ng ml?1 to 1.0 µg ml?1 for the analytes in rat brain. Intra‐ and inter‐day precision and accuracy of analytes were well within acceptance criteria (15%). Mean extraction recoveries of analytes and IS from rat brain were all more than 80.0%. Furthermore, the validated method was successfully applied to comparing profiles of analytes in normal and insomnic rat brains. Results indicated that there were statistically significant differences for serotonin, 5‐HIAA, DA, NE, Glu and Ach, but no significant difference for Try and GABA between two groups. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

19.
20.
Abnormal production or metabolism of steroid hormones is responsible for the development of endocrine diseases. Thus, accurate quantification of steroid hormones is needed for both research into clinical conditions and diagnostic and monitoring purposes. An improved analytical method for profiling 39 steroids in urine using LC–MS/MS was developed. As a pre-treatment procedure prior to LC–tandem mass spectrometry (LC–MS/MS) analysis, hydrolysis using β-glucuronidase and solid-phase extraction for purifying the samples were performed. Steroids were separated using Waters ACQUITY BEH C18 column (2.1 × 100 mm, 1.7 μm) and a mobile phase consisting of eluent A (0.01% formic acid and 1 mm ammonium formate in water) and eluent B (0.01% formic acid and 1 mm ammonium formate in methanol) with a gradient program at a flow rate of 0.4 mL/min. Under the optimized method, the linearity of calibration curves was higher than 0.992. The limits of detection at signal-to-noise ratio of 3 were 0.03–90 ng/mL. The developed novel LC–MS/MS method can quantitatively profile 39 steroids in a single analytical run. Steroid profiling based on quantitative results could improve the diagnosis and monitoring of hormone-dependent diseases.  相似文献   

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