Analysis of Ginsenosides by SPE-HPLC and Its Application to Quality Control

<正>A rapid and effective method,solid phase extraction coupled with high performance liquid chromatography (SPE-HPLC),was applied to the separation and analysis of ginsenosides.Waters OASIS HLB was used for concentrating and purifying samples and Alltima C_(18)(53 mm×7 mm,3μm) chromatography column was used for separating ginsenoside Rg_1,Re,Rb_1,Rc,Rb_2 and Rd.These ginsenosides were analyzed within 20 min in our gradient elution process and the equilibrium time of the chromatography column cost only 5 min.Moreover,there was no obvious baseline drift in our experiment.This method was used to analyze the contents of ginsenosides in different ginseng products for quality control.Four ginseng products were studied,including two kinds of capsules,one kind of tablet and one kind of injection.The results show that the method developed in this paper had good accuracy,linearity and precision.Therefore,this method could be applied in quality control of ginseng products.     

Determination of levels of adenosine phosphates in blood by ion chromatography

A new method was developed for simultaneous determination of levels of AMP,ADP and ATP in blood by anion-exchange chromatography.The three adenosine phosphates were separated by Dionex IonPac AG18(50 mm×4 mm) guard column and IonPac AS 18(250 mm×4 mm) analytical column using a gradient method and detected with a suppressed conductivity detector. The detection limits(S/N=3) of AMP,ADP and ATP were 38,47,108 ng/L,respectively.The relative standard deviations of retention time,peak area and peak height were all less than 1.87%and a good linear relationship was obtained.This method was applied to analyze human blood samples.     

气相色谱法检测去甲斑蝥素片含量

GC method for direct quantitative determination of Norcantharidi in tablets was developed.The condi-tions for determination were:FID detector at 210℃;column:2%OV-17 Chromosorb W(AW- DMCS 80～100 mesh(2m×3mm i.d),temperature at 165℃; injector at 210℃. Vanillin as internal standard. Theresponse was linear between 0.2mg/mL and 1.6mg/mL。The average recovery was 100.03/with a coeffi-cient of variation of 0. 97%。This method is proved to be highly sensitive,good reproducible and simple forpre-treatment.     

Rapid Separation on Activated Charcoal of High Oligosaccharides in Honey

A novel, simple and rapid stability-indicating high-performance liquid chromatographic (HPLC) method for pravastatin sodium (PRA) was successfully developed and validated for the assay of in tablets. Chromatographic separation was achieved isocratically on a C₁₈ column (150 mm × 4.6 mm) utilizing a mobile phase of methanol-phosphate buffer (pH 7; 0.02 M) (57:43, v/v) at a flow rate of 1.0 mL min⁻¹ with UV detection at 238 nm. A linear response (r = 0.9999) was observed in the range of 1–5 μg mL⁻¹. The method showed good recoveries (100.50%) and the relative standard deviation of intra and inter-day were 1.40%. The method can be used for both quality control assay of pravastatin in tablets and for stability studies as the method separates pravastatin from its degradation products and tablet excipients.An erratum to this article can be found at     

Separation,determination of six impurities in methotrexate drug substance using ultra-performance liquid chromatography

Methotrexate(MTX) is an antineoplastic therapeutic medicine as antimetabolite of folic acid. In this paper, a sensitive and rapid ultra-performance liquid chromatographic(UPLC) method was developed and validated for the separation and determination of impurities in MTX drug substances. The UPLC method was accomplished on an Agilent Zorbax Extend C-18(50 mm 4.6 mm, 1.8 mm) with a gradient elution system composed of sodium dihydrogen phosphate in water(20 mmol/L, pH 3.0) and acetonitrile. The flow rate was 2.2 mL/min. The method was validated. The calibration curves displayed good linearity(r 0.999) within the tested concentration ranges. The limit of detection(LOD) and limit of quantification(LOQ) of the six analytes were all less than 0.774 mg/mL and 1.03 mg/mL. The relative standard deviation(RSD) for intra- and inter-day precision of the six analytes was less than 9.8%, including at the LOQ. The average recovery ranged from 95.2% to 103% except at the LOQ, where recovery ranged from 82.7% to 117%. The validated method was successfully used to determine the relative abundance of six impurities in the MTX drug substances.     

高效液相色谱法测定福丽生发液中柚皮甙的含量

 This paper describes a method for determining naringin in Fully Hair Regenerator by reversed-phaseHPLC with a 150mm×4.6mm i.d.YWGCis column.It is eluted with methanol-acetic acid-water(20∶ 4∶76)mixture at a flowrate of 1.0mL/min and detected at 283 nm.The coefficient of variation was less than1.0%,and the recoverv was more than 97.4%.The method is simple,rapid,sensitive and of excellent pre-cision.     

Development and Validation of a LC Method for the Determination of Pramipexole Using an Experimental Design

A rapid and sensitive RP-HPLC method with UV detection for routine control of pramipexole in tablets was developed. Chromatography was performed with mobile phase containing a mixture of acetonitrile/phosphate buffer (60/40; v/v) with a flow rate of 0.8 mL min⁻¹. Quantitation was accomplished with the internal standard method; the procedure was validated by linearity (correlation coefficient = 0.99892), accuracy, robustness and intermediate precision. Limit of quantitation and limit of detection were found to be 4.5 μg and 1.4 μg respectively, which indicates the method is highly sensitive. Experimental design was used during validation to calculate method robustness and intermediate precision, for robustness test three factors were considered; percentage v/v of acetonitrile, flow rate and pH; an increase in the flow rate results in a decrease of concentration found of the drug, while the percentage of organic modifier and temperature have no important effect on the response. For intermediate precision measure the considered variables were: analyst, equipment, days and obtained RSD value (0.56%, n=24) which indicated a good precision of the analytical method. The method was found to be applicable for determination of the drug in tablet formulations and the results of the developed method were compared with those of the UV spectrophotometric method to access the active pramipexole content. Revised: 13 March and 25 April 2006     

LC-ESI-MS Determination of Bilobalide and Ginkgolides in Canine Plasma

A sensitive and selective method using liquid chromatography with electrospray ionization mass spectrometric detection was developed for the quantification of bilobalide and ginkgolides in canine plasma. The analytes were extracted with diethyl ether-dichloromethane-isopropanol (6:3:1, v/v) after spiking the samples with daidzein (internal standard). The lower limit of quantification (LLOQ) of the method was 2.5 μg L⁻¹ for ginkgolide B and 10.0 μg L⁻¹ for bilabolide, ginkgolide A and ginkgolide C. The accuracy of the method was within 15% of the actual values over a wide range of plasma concentrations. The intra-day and inter-day precision was better than 15% (R.S.D.). Finally, the LC-ESI-MS method was successfully applied to study the pharmacokinetics of ginkgolides and bilabolide after administration of Ginkgo biloba extracts to dogs.     

扑杀特的高效液相色谱分析

An RP-HPLC method for the quantitative deternunation of imazethapyr in technical product and formula-ion has been developed. Operating conditions were YWG-C18 colunmn,25cm×5.0mm i.d,methanol-water-glacial acetic acid(80 : 20: 1. 2 ,volume ratio) eluent and UV-254nm dstection.The method is reproducibieand the coefficient of variation was less than 1.5%.     

Growth, Band Structure and Optical Properties of LiSrBO3 Crystal

The bulk crystal of LiSrBO3 (8.39 g) with a size of 21mm×20mm×15mm was grown by high temperature solution growth method. The relationship between growth habit and crystal structure was discussed. The transmission spectrum shows an UV absorption edge at about 300 nm. The melting temperature of this crystal was determined to be 942 ℃ by DTA-TG measurement. The band structure of the LiSrBO3 crystal was studied by means of the first principle method. An indirect band gap was found to be about 4.0 eV,and a low dielectric constant was estimated to be about 1.9 in terms of theoretical results.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。