首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
JPC – Journal of Planar Chromatography – Modern TLC - Quantitative high-performance thin-layer chromatography (HPTLC) analysis of triterpene saponins in different parts of eight...  相似文献   

2.
JPC – Journal of Planar Chromatography – Modern TLC - The fruit of Piper longum Linn. (family: Piperaceae), known as pippali in India, is a reputed drug of Ayurveda (the Indian system...  相似文献   

3.
A high-performance thin layer chromatographic method coupled with densitometric analysis has been developed for measurement of benazepril and cilazapril, both pure and in their commercial dosage forms. The active substances were extracted from tablets with methanol (mean recovery 102%) and chromatographed on silica gel 60 F254 HPTLC plates in horizontal chambers with ethyl acetate–acetone–acetic acid–water, 8:2:0.5:0.5 (v/v), as mobile phase. Chromatographic separation of these ACE inhibitors was followed by UV densitometric quantitation at 215 nm. Calibration plots were constructed in the range 0.4 to 2.0 g L–1 for benazepril (2.0–10.0 g spot–1) and from 0.5 to 1.5 g L–1 for cilazapril (4.0–12.0 g spot–1) with good correlation coefficients (r 0.990). The method was used to determine benazepril and cilazapril in pharmaceutical preparations with satisfactory precision (1.4% < RSD < 5.6%) and accuracy (1.7 < RE < 5.1).  相似文献   

4.
JPC – Journal of Planar Chromatography – Modern TLC - The antihypertensive effect of sartans is a result of inhibition of the binding of angiotensin (AT) II to the AT1 receptor in...  相似文献   

5.
JPC – Journal of Planar Chromatography – Modern TLC - A reliable and sensitive thin-layer chromatographic (TLC)-densitometric method is developed for the analysis of danazol in its...  相似文献   

6.
In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients.We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA),satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.  相似文献   

7.
JPC – Journal of Planar Chromatography – Modern TLC - A simple, selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed for the...  相似文献   

8.
A short and practical preparation of α-asarone was developed using the inexpensive methylisoeugenol as a starting material. The utilization of a sequence of tribromination, debromination, and copper-mediated aromatic substitution enabled the stereoselective formation of only the E-isomer of α-asarone in good yield.  相似文献   

9.
JPC – Journal of Planar Chromatography – Modern TLC - A selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed for the analysis...  相似文献   

10.
JPC – Journal of Planar Chromatography – Modern TLC - The present article focuses on the quantitative analysis of a polyherbal formulation containing arjuna, guggul, and pushkarmoola in...  相似文献   

11.
A sensitive and specific high-performance liquid chromatography–tandem mass spectrometry method has been developed and validated for the determination of clonazepam in rat plasma. Clonazepam and internal standard diazepam were extracted from plasma samples by a single-step protein precipitation. The chromatographic separation was performed on a Dikma ODS-C18 reversed-phase column at 40 °C. The mobile phase composed of a premix of solvent A (0.1% formic acid–4 mM ammonium acetate–water)–solvent B (acetonitrile) (13:87, v/v) at a flow-rate of 0.7 mL min?1. Positive electrospray ionization was utilized as the ionization source. Clonazepam and the internal standard were determined using multiple reaction monitoring of precursor → product ion transitions at m/z 316.0 → 270.0 and m/z 285.1 → 193.2, respectively. The lower limit of quantification was 0.25 ng mL?1 using 50 μL plasma samples and the linear calibration range was from 0.25 to 128 ng mL?1. The within- and between-batch RSDs were lower than 15% and the relative recoveries of clonazepam ranged from 97.4 to 104.7%. The mean extraction recoveries of clonazepam and IS were 79.7 and 77.6%, respectively. The method has been successfully applied to the pharmacokinetic studies in rat after oral administration of clonazepam.  相似文献   

12.
A simple, rapid and sensitive liquid chromatographic method using a refractive index detector has been developed and validated for identification and quantification of β-cyclodextrin in milk, cream and butter. The chromatographic system consists of a YMC ODS-AQ column packed with C18 reversed phase silica packing material as stationary phase using a mixture of methanol and water 7:93% (v/v) as the mobile phase. Linearity was established for the β-cyclodextrin concentration in the range 0.01–4 mg mL?1, with a coefficient (r) of 0.9998. Repeatability of the method was assessed; the coefficient of variation for β-cyclodextrin range were 1.24, 3.01, and 5.36% for milk, cream and butter. Recoveries ranged between 99.91 and 94.53%. This method was highly reproducible and reliable for quantification of treated milk with β-cyclodextrin for removal cholesterol from the milk fat.  相似文献   

13.
《Analytical letters》2012,45(1):45-57
Abstract

Sensitive determination of tumor marker carcinoembryonic antigen (CEA) by capillary electrophoresis–chemiluminescence detection (CE-CL) has been developed using an internal standard method. Parameters affecting the CE separation and CL detection were systematically optimized. Under the optimal conditions, the free horseradish peroxidase (HRP)–labeled antibody (Ab?), the bound Ab?-antigen complex (Ab?-Ag), and HRP used as internal standard were well separated within 5 min. The proposed method was successfully applied for the quantification of CEA in human sera obtained from both healthy persons and patients.  相似文献   

14.
JPC – Journal of Planar Chromatography – Modern TLC - Two different botanical sources, Eclipta alba and Wedelia calen-dulacea are used as “Bhringaraja” in the Ayurvedic...  相似文献   

15.

Acorus calamus (sweet flag) is used in the traditional Chinese and Indian medicines for various ailments. Due to its extensive use in herbal medicine, natural resources from the world’s forests are being depleted at an alarming rate. In the present study, an in vitro cell culture technique is being explored as an alternative to field grown A. calamus with respect to the metabolite profile, antioxidant properties, total phenol, and total flavonoid content. Gas chromatography mass spectrometry (GC–MS) was utilized to compare the metabolite profiling between methanolic extracts of in vitro and field grown rhizome tissues of A. calamus. A statistical analysis indicated an upregulation of α-selinene, which is representative of sesquiterpene ketones, and a cyclic polyol, d-pinitol, which has an insulin mimicking effect in the in vitro cultivated rhizome tissue when compared to field grown rhizomes. Significantly higher free-radical scavenging activity (IC50 69.32 μg mL−1), total phenolic content (71.60 mg GAE g−1), and total flavonoid content (42.34 mg CE g−1) were observed in in vitro rhizome tissues compared with those from field grown rhizomes. These observations suggest that the in vitro cultivation of Acorus rhizomes could be exploited as an alternative to field grown A. calamus, as it is an endangered medicinal plant. The production of useful metabolites by the in vitro cultured rhizomes can be explored successfully for utilization by various food and drug industries.

  相似文献   

16.
17.
Abstract

A simple and rapid reversed-phase liquid chromatographic method for the determination of alprazolam and a-hydroxyalprazolam in plasma is described. Flunictrazepam was used as internal standard. Plasma samples were buffered with sodium borate and extracted with dichloromethane /n-pentane 4:6 v/v for 60 sec on a vortex apparatus. Extraction solvent was evaporated to dryness and extraction residues were reconstituted in the mobile phase. Samples were chromatographed on a 5μ Lichrospher RP-18 column (25cm × 4mm i. d) using acetonitrile/water 40:60 v/v as the mobile phase. The column effluent was monitored at 230nm. The lower limit of detection was 1ng/ml for alprazolam and a-hydroxyalprazolam while the lower limit of quantification was 2ng/ml for both compounds. Peak height and plasma  相似文献   

18.
During heat sterilization of peritoneal dialysis solutions, glucose is partially transformed into glucose degradation products (GDPs), which significantly reduce the biocompatibility of these medicinal products. Targeted α-dicarbonyl screening identified glyoxal, methylglyoxal, 3-deoxyglucosone, 3,4-dideooxyglucosone-3-ene, glucosone, and 3-deoxygalactosone as the major six GDPs with α-dicarbonyl structure. In the present study, an ultra-high-performance liquid chromatography method was developed which allows the separation of all relevant α-dicarbonyl GDPs within a run time of 15 min after derivatization with o-phenylenediamine. Hyphenated diode array detection/tandem mass spectrometry detection provides very robust quantification and, at the same time, unequivocal peak confirmation. Systematic evaluation of the derivatization process resulted in an optimal derivatization period that provided maximal derivatization yield, minimal de novo formation (uncertainty range ±5%), and maximal sample throughput. The limit of detection of the method ranged from 0.13 to 0.19 μM and the limit of quantification from 0.40 to 0.57 μM. Relative standard deviations were below 5%, and recovery rates ranged between 91% and 154%, dependent on the type and concentration of the analyte (in 87 out of 90 samples, recovery rates were 100 ± 15%). The method was then applied for the analysis of commercial peritoneal dialysis fluids (nine different product types, samples from three lots of each).  相似文献   

19.
Abstract

A reverse-phase high-performance liquid chromatographic method for the quantitative determination of α-amanitin in serum of poisoned patients is described and discussed. The methodology developed is simple and rapid with a minimum of sample preparation steps required. Detection is very sensitive, allowing quantitation of 25 ng of α-amanitin/ml of serum. The technique described is a useful tool to determine the severity of Amanita phalloides intoxication during the first 24 h after ingestion of poisonous mushrooms.  相似文献   

20.
A sensitive and selective LC–MS/MS method for the quantification of the atypical antipsychotic agent quetiapine and its metabolite norquetiapine (N-desalkyl quetiapine) was developed and validated. Following the protein precipitation technique, the analytes were separated using a reversed phase column with gradient elution. The compounds were ionized in the electrospray positive ionization (ESI+) ion source tandem MS detection in multiple reaction monitoring (MRM) mode. Calibration curves were generated by plotting the peak area ratio of quetiapine and norquetiapine to the IS clozapine for each calibration concentration. The method provides a linear response from a quantitation range of 2.3–452.9 nM (0.9–173.7 ng/mL) and 2.7–543.0 nM (1.0–200.0 ng/mL) for quetiapine and norquetiapine, respectively. Regression analysis showed a correlation coefficient greater than 0.999 and 0.991 for quetiapine and norquetiapine, respectively. To evaluate the metabolism of quetiapine by the cytochrome P450 in microsomes, the method has been subsequently employed. LC–MS/MS procedure has been carried out to determine increasing concentrations of both drugs in microsomal matrix obtained by a pool of mammalian liver microsomes BD UltraPoolTM Human Liver Microsomes (HLM 150).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号