共查询到20条相似文献,搜索用时 0 毫秒
1.
A sensitive and efficient method was developed for determination of metoprolol in human plasma by gas chromatography-mass spectrometry (GC-MS). Metoprolol and atenolol (internal standard, IS) were extracted from human plasma with a mixture of ethylacetate and diethylether at basic pH with liquid-liquid extraction. Calibration curves were linear over the concentration range 15-500 ng/ml. Intra- and inter-day precision values for metoprolol in human plasma were less than 6.4, and accuracy (relative error) was better than 8.8%. The analytical recovery of metoprolol from human plasma averaged 91.20%. The limits of detection (LOD) and quantification (LOQ) of metoprolol were 5.0 and 15 ng/ml, respectively. Also the developed and validated GC-MS method was successfully applied to three patients with hypertension who had been given an oral tablet of 100 mg metoprolol. 相似文献
2.
A highly selective and sensitive method for the determination of 30 meta- and para-substituted alkylphenols from phenol (C0) to nonylphenol (C9) in biota is described. Dichloromethane extracts of spiked cod liver and muscle samples are cleaned up by gel permeation chromatography, derivatised with pentafluorobenzoyl chloride and analysed by gas chromatography-mass spectrometry with negative-ion chemical ionisation. Quantification is done with isotope dilution of five internal standards of different chain length. The detection limits were in the low microg/kg levels. There were encountered problems with background levels of 4-nonylphenol. 4-Nonylphenol isomers were found in a number of plastic and rubber products used in the laboratory. 相似文献
3.
Gas chromatography-mass spectrometry method for the simultaneous determination of wood extractive compounds in quaking aspen 总被引:1,自引:0,他引:1
We have developed a rapid gas chromatography-mass spectrometry (GC-MS) method for the detailed compositional analysis of 70 underivatized wood extractive components present in quaking aspen (Populus tremuloides Michx.). Forty-four compounds were unequivocally identified by retention time and mass spectral comparison with standards. An additional 26 chromatographic peaks were assigned to broad chemical classes using retention time and mass spectra features. The results were compared to the respective tert.-butyldimethylsilyl derivatized wood extractives profile, and it was determined that derivatization was unnecessary for the GC-MS analysis of the target compounds. 相似文献
4.
Determination of clenbuterol in urine as its cyclic boronate derivative by gas chromatography-mass spectrometry 总被引:2,自引:0,他引:2
A rapid and reliable gas chromatographic-mass spectrometric method for the determination of clenbuterol in urine is described. Penbutolol was used as internal standard. Four derivatization procedures have been tested, of which 1-butaneboronic acid gave the best results. The method includes extraction of the alkalinized urine (3 ml) with tert.-butyl methyl ether-n-butanol (9:1), derivatization with 1-butaneboronic acid (15 min at room temperature), and analysis in the selected-ion monitoring mode of the derivatives of clenbuterol at m/z 243, 327 and 342 and of penbutolol at m/z 342 and 357. The detection limit is 0.5 ng/ml and the recovery better than 90%. 相似文献
5.
6.
R T Coutts G A Torok-Both L V Chu Y K Tam F M Pasutto 《Journal of chromatography. A》1987,421(2):267-280
The metabolism of a large dose (40 mg/kg intraperitoneally) of lidocaine (LIDO) in mature male Sprague-Dawley rats is described. Pentafluorobenzoyl chloride was used to derivatize the hydrolyzed urinary metabolites prior to extraction and analysis as pentafluorobenzoyl-derivatives by combined gas chromatography-mass spectrometry. Total ion and selected ion current (m/z 195; C6F5CO+) traces were recorded and metabolites of LIDO were readily identified. Only one major metabolite, 3-hydroxy-N-(N-ethylglycyl)-2,6-xylidine, was excreted in urine. A new metabolite, 3-hydroxy-N-glycyl-2,6-xylidine was also present in significant amounts, as well as minor quantities of four oxygenated metabolites of N-(N-ethylglycyl)-2,6-xylidine. Other known metabolites of LIDO, including 3-hydroxylidocaine, were excreted in trace quantities. The results suggest that metabolism of LIDO in rats may be age- and/or dose-dependent. 相似文献
7.
1-(2-Thenoyl)-4-trifluoro-2-[2-hydroxy-3-sulfo-5-nitrophenylazo]butadione-1,3 (H2L) was synthesized from 2-thenoyltrifluoroacetone. The formation of a copper(II) complex of the synthesized reagent was studied in the presence and absence of 8-hydroxyquinoline (HR). Monoligand [Cu(HL)2] and mixed-ligand [Cu(HL)2HR] compounds were obtained at pH 4 and 3, respectively. The ratio of components in the monoligand and mixed-ligand compounds were 1 : 2 and 1 : 2 : 1, respectively. Beers law was obeyed in the ranges of copper concentrations from 0.20 to 2.56 and from 0.25 to 2.56 µg/mL, respectively. The dissociation constants of the reagent were .K1 = 4.25µ0.01 and .K2 = 8.20µ0.01 . The stability constants of [Cu(HL)2] and [Cu(HL)2HR] complexes were K1 = 4.96µ0.03 and 4.92µ0.01, respectively. A procedure was developed for the photometric determination of copper(II) in rocks.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 2, 2005, pp. 157–161.Original Russian Text Copyright © 2005 by Alieva, Chyragov, Makhmudov.This revised version was published online in April 2005 with corrections to the author names and book review format. 相似文献
8.
A selective reaction of ethyl carbamate (urethane) and methyl urethane (urethylane), as internal standard, with xanthydrol was effected to detect urethane after extraction from Italian aqua vitae (grappa) samples. The xanthylamides formed were determined by gas chromatography-mass spectrometry in the selected ion monitoring mode on an apolar DB 5 silica column. The linearity of the method was tested from 10 to 1000 micrograms/l, with a detection limit of 1 micrograms/l. 相似文献
9.
10.
Domestic and office dust samples (n=37) were analyzed for hexabromocyclododecanes (HBCDs) using gas chromatography-electron-capture negative ionization-mass spectrometry (GC-ECNI/MS) and liquid chromatography-electrospray tandem mass spectrometry (LC-ESI/MS/MS). To determine the best method to quantify HBCDs using GC-ECNI/MS, BDE 128 was used as internal standard (I.S.) in all samples, while 13C-labeled alpha-HBCD was used as I.S. in some samples. Total HBCD concentrations (sum of alpha-, beta-, and gamma-HBCD diastereomers) were calculated using response factors (RFs) for alpha- and gamma-HBCD as individual diastereomers and using an average RF for both diastereomers. Statistical comparison showed that concentrations obtained via GC-ECNI/MS were statistically indistinguishable (p>0.05) from those obtained using LC-ESI/MS/MS. The closest match between the two techniques was obtained using [13C]alpha-HBCD as I.S. and the average RF for alpha- and gamma-HBCDs. Excellent linear correlations (Pearson coefficient values r>0.9) were obtained between the GC-ECNI/MS and LC-ESI/MS/MS results, with slopes ranging from 0.76 to 1.36. Pentabromocyclododecenes (four isomers) and tetrabromocyclododecadienes (two isomers) were detected in the studied samples and were identified as degradation products of HBCDs after separation from the parent compound on the basis of both retention time and mass spectrum. This finding suggests that the elimination of HBr is the major degradation pathway for HBCDs in dust. 相似文献
11.
A comparative study of the performance of liquid chromatography (LC)-atmospheric pressure chemical ionisation (APCI)-mass spectrometry (MS) and gas chromatography (GC)-mass spectrometry techniques for the determination of resin and fatty acids from paper mill process waters was carried out. These compounds are responsible for the high toxicity of paper mill effluents and little research has been carried out regarding their analysis using mass spectrometric techniques. To prove the usability of GC and LC-MS, 16 treated and untreated water samples of recycle, kraft and pulp paper mills were analysed and good agreement was observed as regards to compounds detected and corresponding concentrations. This paper also reports the limits of detection, recoveries, reproducibility, linearity and precision using the two methods. GC-MS presented better selectivity and lower detection limits (below 0.2 microg/l), but derivatization of the extracts and the short life of derivatives (12-24 h) made the technique tedious and prone to high variations. Although LC-APCI-MS presented coelution of the non-aromatic resin acids, it also showed good sensitivity (limits of detection <3 microg/l) and permitted the detection of resin and fatty acids at microg/l level. In addition, since samples could be directly injected to the chromatographic system, LC-APCI-MS was proven as a powerful technique for quick and unequivocal quality control during papermaking. 相似文献
12.
Development of a gas chromatography-mass spectrometry method for the determination of household insecticides in indoor air 总被引:3,自引:0,他引:3
This work presents a GC-MS method for the determination of 17 household insecticides and acaricides in indoor air. Air samples were collected with a sampling train which consisted of a glass fibre filter and two polyurethane foam plugs, followed by a high-volume air pump. Filters and plugs were analysed separately. The overall recoveries ranged from 85 to 109% (4-11% RSD). Minimum method detection limits between 0.1 and 5 ng/m3 were determined. 相似文献
13.
比值导数荧光光谱法同时测定色氨酸和5-羟基色氨酸 总被引:2,自引:0,他引:2
建立了比值导数荧光光谱法同时测定色氨酸和5-羟基色氨酸的方法。在比值导数荧光光谱法中,色氨酸浓度在4.0×10-6~2.0×10-5mol/L范围内比值导数荧光光谱峰高与其浓度成正比,线性相关系数为0.9901,检出限为1.3×10-7mol/L。5-羟基色氨酸浓度在4.0×10-8~2.0×10-5mol/L范围内比值导数光谱峰高与其浓度成正比,线性相关系数为0.9996,检出限为1.3×10-8mol/L。同时测定了实际样品中的色氨酸和5-羟基色氨酸,测定结果与高效液相色谱法有良好的一致性。 相似文献
14.
15.
16.
Two laboratory-based linear horizontal agitation methods for determining a range of phthalate esters from soft polyvinyl chloride (PVC) toys are presented in compliance with EU legislation. Both of these methods were validated through interlaboratory trials using a PVC reference disc and four soft PVC toy/childcare articles intended or likely to be mouthed. Two of these commercial samples contained diisononyl phthalate (DINP), one diisodecyl phthalate (DIDP) and one bis(2-ethylhexyl) phthalate (DEHP). Acceptable repeatability (r, within-laboratory) and reproducibility (R, between-laboratory) data were demonstrated for both the analytical detection technique (GC-MS) (r = 9.8% and R = 8.1%) and agitation/extraction procedure (r=21.9% and R = 35.3% at 37 degrees C; r = 22.7% and R = 31.1% at 65 degrees C) for DINP. This was achieved through the participation of six laboratories. The remaining three phthalates from the EU Scientific Committee for Toxicity, Ecotoxicity and the Environment (CSTEE) list--dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di-n-octyl phthalate (DnOP)--were not tested due to the unavailability of suitable materials. 相似文献
17.
Quantitative determination of thiabendazole, as its methyl derivative, has been achieved by gas-liquid chromatography with flame ionization detection and a column of 10% of DC-200 on Gas-Chrom Q at 240 degrees. Determination was possible with 10 to 200 ng per mul of the methylated reaction mixture. For determining thiabendazole in fruits, clean-up of the crude extracts by liquid-liquid partition allows satisfactory elimination of interference and permits determination in concentrations down to 0.1 ppm. The recovery of thiabendazole added to fruits at the 0.5-ppm level ranges from 90.3 to 94.9%. The methyl derivative was identified as N-methylthiabendazole by its elementary composition, by its melting-point, and by ultraviolet, infrared, mass and nuclear magnetic resonance spectroscopy. 相似文献
18.
A sensitive gas chromatographic method was developed for the determination of Trelibet, 1-benzyl-4-(2'-pyridinecarbonyl)piperazine, and of its major metabolites in biological fluids. The compounds were extracted as bases into dichloromethane, and the extracts were analysed by a dimethylsilicone capillary column with a nitrogen-phosphorus flame-ionization detector. The lower limit of detection was 1 ng/ml for Trelibet and 5 ng/ml for the metabolites. Peak-area ratios of the compounds and internal standard were linearly correlated to their plasma concentrations between 1 and 1000 ng/ml. The method was used for quantification of Trelibet and two of its metabolites in depressed patients after oral administration of a single dose of 200 mg of Trelibet. Concentration data measured in plasma and urine showed that the method is sensitive enough to monitor concentrations both for pharmacokinetic studies and for plasma steady-state levels daily. 相似文献
19.
20.
This work describes an effective, low solvent consumption and affordable sample preparation approach for the determination
of eight UV filters in surface and wastewater samples. It involves sorptive extraction of target analytes in a disposable,
technical grade silicone disc (5 mm diameter × 0.6 mm thickness) followed by organic solvent desorption, large volume injection
(LVI), and gas chromatography-mass spectrometry determination. Final working conditions involved overnight extraction of 100-mL
samples, containing 10% of methanol, followed by analytes desorption with 0.2 mL of ethyl acetate. The method provides linear
responses between the limits of quantification (from 0.003 to 0.040 ng mL−1) and 10 ng mL−1, an intra-day precision below 13%, and low matrix effects for surface, swimming pool, and treated sewage water samples. Moreover,
the extraction yields provided by silicone discs were in excellent agreement with those achieved using polydimethylsiloxane-covered
stir bars. Several UV filters were found in surface and sewage water samples, with the maximum concentrations corresponding
to octocrylene. 相似文献