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991.
A new method was developed and fully validated for the quantitation of benazepril, benazeprilat and hydrochlorothiazide in human plasma. Sample pretreatment was achieved by solid-phase extraction (SPE) using Oasis HLB cartridges. The extracts were analysed by high-performance liquid chromatography (HPLC) coupled to a single-quadrupole mass spectrometer (MS) with an electrospray ionization interface. The MS system was operated in selected ion monitoring (SIM) modes. HPLC was performed isocratically on a reversed-phase porous graphitized carbon (PGC) analytical column (2.1 x 125.0 mm i.d., particle size 5 microm). The mobile phase consisted of 55% acetonitrile in water containing 0.3% v/v formic acid and pumped at a flow rate of 0.15 ml min(-1). Chlorthalidone was used as the internal standard (IS) for quantitation. The assay was linear over a concentration range of 5.0-500 ng ml(-1) for all the compounds analysed, with a limit of quantitation of 5 ng ml(-1) for all the compounds. Quality control (QC) samples (5, 10, 100 and 500 ng ml(-1)) in five replicates from three different runs of analyses demonstrated intra-assay precision (coefficient of variation (CV) < or =14.6%), inter-assay precision (CV < or = 5.6%) and overall accuracy (relative error less than -8.0%). The method can be used to quantify benazepril, benazeprilat and hydrochlorothiazide in human plasma, covering a variety of pharmacokinetic or bioequivalence studies. 相似文献
992.
Lee HW Park WS Kim YW Cho SH Kim SS Seo JH Lee KT 《Journal of mass spectrometry : JMS》2006,41(7):855-860
We have developed and validated a simple detection system with high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometry (ESI-MS/MS) for determining cimetropium levels in human plasma using scopolamine butyl bromide as an internal standard (I.S.). The acquisition was performed in the multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 357.9 > 103.1 for cimetropium and m/z 359.9 > 103.1 for butyl-scopolamine. The method involves a simple single-step liquid-liquid extraction with dichloromethane. The analyte was chromatographed on an YMC C18 reversed-phase chromatographic column by isocratic elution with 10 mM ammonium formate buffer-methanol (19:81, v/v; adjusted to pH 4.0 with formic acid). The results were linear over the studied range (0.2-100 ng ml(-1)), with r2 = 1.0000, and the total analysis time for each run was 2 min. Intra- and interassay precisions were 0.70-8.54% and 1.08-4.85%, respectively, and intra- and interassay accuracies were 97.56-108.23% and 97.48-103.91%, respectively. The lower limit of quantification (LLOQ) was 0.2 ng ml(-1). At this concentration, mean intra- and interassay precisions were 8.54% and 4.85%, respectively, and mean intra- and interassay accuracies were 97.56% and 98.91%, respectively. The mean recovery ranged from 62.71 +/- 4.06 to 64.23 +/- 2.32%. Cimetropium was found to be stable in plasma samples under typical storage and processing conditions. The devised assay was successfully applied to a pharmacokinetic study of cimetropium bromide administered as a single oral dose (150 mg) to healthy volunteers. 相似文献
993.
Buratti M Pellegrino O Valla C Rubino FM Verduci C Colombi A 《Biomedical chromatography : BMC》2006,20(9):971-978
A method suitable for the determination of unmetabolized polycyclic aromatic hydrocarbons (PAHs) excreted at trace levels (ng/L) in human urine for the monitoring of exposure of the general population to PAH contamination was developed. PAHs were determined, after enrichment by solid-phase extraction on polyurethane foam (PUF) chips, by HPLC with fluorescence detection. Different parameters affecting analyte extraction to the PUF, including urine salting-out and organic additives, and optimization of conditions for clean-up and desorption have been investigated. Optimized conditions were 40 mL acidified urine sample, added with magnesium sulfate, tetrahydrofuran and a 2 cm3 PUF chip, and extracted by shaking at 30 rpm for 1 h at ambient temperature. Desorption was performed, after a clean-up step with diluted sodium hydroxide, using a small amount of diethyl ether. The recovery of PAH congeners from spiked urines was >90% in the 2-100 ng/L range; the detection limit was 0.1-0.5 ng/L, depending on the considered PAH congener; day-to-day precision, at 50 ng/L native PAH content, was CV = 10-20%. The proposed technique provides a simple, economical and effective procedure for the determination of trace amounts of unmetabolized PAHs excreted in human urine spot samples. 相似文献
994.
Nirogi RV Kandikere VN Shrivasthava W Mudigonda K 《Biomedical chromatography : BMC》2006,20(10):1103-1108
A simple, reliable HPLC method with fluorescence detection (excitation 320 and emission 388 nm) was developed and validated for quantitation of zolpidem in human plasma. Following a single-step liquid-liquid extraction, the analyte and internal standard (quinine) were separated using an isocratic mobile phase on a reversed-phase C(18) column. The lower limit of quantitation was 1.8 ng/mL, with a relative standard deviation of less than 5%. A linear dynamic range of 1.8-288 ng/mL was established. This HPLC method was validated with between-batch and within-batch precision of 1.7-4.8 and 1.2-2.3%, respectively. The between-batch and within-batch accuracy was 95.3-100.4 and 95.5-102.7%, respectively. Frequently coadministered drugs did not interfere with the described methodology. Stability of zolpidem in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method is simple and repeatable enough to be used in pharmacokinetic studies. 相似文献
995.
Hai Yen Thi Phan Takashi Yano Hai Anh Thi Phan Tsuyoshi Nishimura Tetsumi Sato Yoritaka Hashimoto 《Applied Acoustics》2010,71(2):107-114
Vietnam is a developing country in southeast Asia, and its environment has been seriously affected by industrialization and urbanization. In large cities like Hanoi (northern Vietnam) and Ho Chi Minh City (southern Vietnam), noise emission from road traffic has been found to be a serious concern among general public. In 2005 and 2007, two large-scale socio-acoustic surveys of community response to road traffic noise were conducted to investigate human reactions to road traffic noise in these cities; the sample sizes were 1503 people in Hanoi and 1471 in Ho Chi Minh City. The noise exposure levels (Lden) were 70–83 dB in Hanoi and 75–83 dB in Ho Chi Minh City. Noise annoyance was estimated using standardized annoyance scales. For both cities, dose–response relationships were established between Lden and the percentage of highly annoyed respondents. Compared to annoyance responses of European people, Vietnamese were less annoyed by road traffic noise by about 5 dB. Hanoi respondents seemed to be more annoyed by noise than Ho Chi Minh City respondents. Conversation and sleep disturbances were not as serious as expected in either city. Furthermore, window orientation in the home was found to affect activity disturbances. 相似文献
996.
Pyoung Jik Lee 《Applied Acoustics》2010,71(9):870-875
In the present study, the effects of different noise combinations on sleep were assessed in two contexts, with a single noise source and with combined noise sources. Road traffic noise, and construction or movie noise combined with road traffic noise were used as the single noise source and the combined noise sources, respectively. When the sound pressure level of road traffic noise was kept constant, levels of the construction and movie noise were changed. Twenty participants were followed for approximately 2 weeks, during which their sleep was evaluated using a questionnaire, including questions on sleeping behavior, premature awakening, and subjective responses. The results showed that the combined noise sources including construction noise decreased the number of participants who fell asleep within an hour and increased the number that were awakened prematurely compared to the effects of road traffic noise combined with movie noise. However, similar tendencies were observed while evaluating sleep quality, sleep disturbance, and annoyance. 相似文献
997.
998.
999.
以温州医学院运动人体科学专业培养计划为切入点,结合国内部分高校运动人体科学办学特点,借鉴国外专业人才培养经验,运用个案研究法、文献资料法及调查法等方法对运动人体科学专业实践能力培养的教学模式进行研究,提出四年制运动人体科学专业本科人才培养期间,在加强课程实践教学环节同时,应更大程度的加大非课程实践教学内容,这对于提高学生实践能力及提升毕业就业竞争力有着极大促进作用。 相似文献
1000.
对于电力系统来说,不管是系统的稳态过程还是暂态过程,我们总是希望电力系统能够稳定地运行.文章就电力系统的暂态稳定问题作相关讨论,通过由大扰动引起的稳定性问题,分析电力系统暂态稳定的物理过程,并研究如何提高电力系统暂态稳定的措施,以期为现代电力系统的可靠、安全运行提供有益的参考. 相似文献