Characterization of calendula flower, milk-thistle fruit, and passion flower tinctures by HPLC-DAD and HPLC-MS

Summary As a part of an investigation of the content of herbal drug preparations and herbal medicinal products, we have investigated tinctures (prepared with 40:60 and 60:40 (%,v/v) ethanolwater) of calendular flower, milk-thistle fruit, and passion flower, which are, respectively, widely used for their anti-inflammatory properties, to treat hepatic injuries, and to treat tension and difficulty falling asleep. The aim of this work was to evaluate the flavonoid content, because flavonoids are the active constituents or markers of these herbal drugs, and to establish the best solvent for the extraction of the constituents. The findings reported herein both confirm the presence of several flavonoids previously identified in these herbal drugs and report the presence of others not previously described and identified here for the first time. In general the flavonol content was highest in 60% tinctures. A rapid, reversed-phase (RP) HPLC assay was developed and validated and enabled good separation of all classes of flavonoids including flavones, flavonols, flavanonols, and flavanolignans. Aglycones and mono, di, and triglycosides (bothO-andC-derivatives) of the flavonoids are also easily and satisfactorily separated. This method is thus proposed for the analysis of other herbal drugs or herbal drug preparations in which flavonoids are the active constituents or markers.     

Simultaneous determination of metformin in combination with rosiglitazone by reversed-phase liquid chromatography

A simple, rapid, and precise reversed-phase liquid chromatographic method is developed for the simultaneous determination of metformin in combination with rosiglitazone. This method uses a Zorbax XDB C(18) 15-cm analytical column, a mobile phase of acetonitrile and buffer containing 10mM disodium hydrogen phsosphate, and 5mM sodium dodecyl sulphate in the ratio of 34:66 (v/v), and pH is adjusted to 7.1 with orthophosphoric acid. The instrumental settings are a flow rate of 1 mL/min, column temperature at 40 degrees C, and detector wavelength of 226 nm. The internal standard method is used for the quantitation of metformin and rosiglitazone. Methylparaben is used as an internal standard. The method is validated and shown to be linear. The correlation coefficients for metformin and rosiglitazone are 0.9996 and 0.9997, respectively. The relative standard deviation for six replicate measurements in two sets of each drug in the tablets is always less than 2%.     

反相高效液相色谱法同时测定食品中14种食品添加剂

采用反相高效液相色谱法研究了一次进样、同时测定食品中苯甲酸、山梨酸、尼泊金甲酯、尼泊金乙酯、尼泊金丙酯、尼泊金丁酯,糖精钠、安赛密,柠檬黄、日落黄、胭脂红、苋菜红、亮蓝及咖啡因等14种食品添加剂的分析方法.实验采用Hypersil ODS柱(4.6×200 mm,5μm,DEAIC)为分离柱,以20 mmol/L乙酸铵(pH 6.8)-甲醇为流动相,用紫外检测器234 nm、254 nm下进行检测,整个分析过程在18 min内完成.被测样品经简单处理后进样,其平均加标回收率为94.5%～99.1%,相对标准偏差小于4.5%.方法适用于食品常规质量检测.     

反相高效液相色谱法同时测定化妆品中7种萘二酚类物质

建立了反相高效液相色谱((RP-HPLC))同时测定化妆品中7种萘二酚类物质的分析方法。膏霜类、乳液类和水类样品用95%(v/v)乙醇提取,粉类样品用95%乙醇-0.1%乙酸(3:2, v/v)溶液提取,经离心、过滤后,用C18柱,以甲醇-0.1%乙酸溶液为流动相梯度洗脱分离,使用二极管阵列检测器检测,以保留时间定性,并以紫外吸收光谱图辅助定性,外标法定量。结果表明,萘二酚类物质在线性范围内线性关系良好,相关系数均不低于0.999 0,方法的定量限(以信噪比为10计)为0.5～1.2 mg/kg,添加水平为5.0～50 mg/kg时回收率为84.0%～102%,相对标准偏差(n=6)为1.3%～5.7%。该法前处理简单、回收率高、精密度好,适用于非蜡基类化妆品中萘二酚类物质的测定。     

Simultaneous determination of alpha-tocopherol and beta-carotene in olive oil by reversed-phase high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method was developed for the determination, in one run, of alpha-tocopherol and beta-carotene in virgin olive oil. The method involved a rapid saponification and a later extraction with a mixture of hexane-ethyl acetate. The chromatographic system consists of an ODS-2 column with a mobile phase of methanol-water-butanol and a diode-array detector. Linearity, precision, recovery and sensitivity were satisfactory. The main advantage of the proposed method is the speed and simultaneous determination of both compounds at the same time.     

反相高效液相色谱法同时测定水样中辛硫磷和氯菊酯

采用AgilentSBC8(5μm,4.6mmi.d.×150mm)色谱柱,以V(乙腈)∶V(水)=70∶30为流动相进行分离,二极管阵列检测器(PDA)在210nm波长处检测,建立了反相高效液相色谱法同时测定辛硫磷和氯菊酯的分析方法。辛硫磷和氯菊酯的线性范围分别为0.1～10μg mL和0.02～10μg mL,检出限分别为0 05和0.01μg mL,实际水样的加标回收率为90.3%和95.3%,相对标准偏差为1.3%和3.2%(n=7)。     

Simultaneous determination of R- and S-prenylamine in plasma and urine by reversed-phase high-performance liquid chromatography

A high-performance liquid chromatographic method for the determination of R- and S-prenylamine in human plasma and urine is described. It involves a two-step liquid-liquid extraction of prenylamine from biological material and preparation of diastereomeric urea derivatives with R-(-)-naphthylethyl isocyanate, a chiral fluorescence marker. Separation and quantitation of the diastereomeric prenylamine derivatives are carried out by a reversed-phase high-performance liquid chromatographic system with fluorimetric detection. The limit of determination is less than 2 ng of enantiomer per ml of urine and less than 1 ng of enantiomer per ml of plasma. A preliminary kinetic study on one healthy volunteer who had received a single oral dose of racemic prenylamine (100-mg film tablet) showed distinctly higher plasma and urine concentrations of the R-enantiomer.     

Simultaneous determination of 5-hydroxymethylfurfural and patulin in apple juice by reversed-phase liquid chromatography.

A rapid, simple and economical method was described for the simultaneous determination of 5-hydroxymethylfurfural (HMF) and patulin in apple juice. The sample was extracted with ethyl acetate and the extract was then cleaned up by extraction with a sodium carbonate solution. Then HMF and patulin were determined by reversed-phase liquid chromatography using a C18 column and a photodiode array detector. HMF and patulin could be completely resolved by using the mixture water-acetonitrile (99:1, v/v) as the mobile phase with a flow rate of 1.0 ml/min. Mean recoveries of HMF ranged from 86% to 100% with an overall mean of 94%, that of patulin ranged from 94% to 125% with an overall mean of 103%, for different spiking levels. The limits of detection for HMF and patulin in apple juice were found to be < 0.01 mg/l and < 5 micrograms/l, respectively.     

Simultaneous determination of metformin and glimepride in pharmaceutical dosage form by reverse-phase liquid chromatography

A simple, rapid, and precise reversed-phase liquid chromatographic method has been developed for the simultaneous determination of metformin in combination with glimepride. Under the developed conditions, good separation of the analytes was achieved in short analysis time. Several parameters affecting the separation of the analytes were studied, including pH and the concentration of SDS. The method is validated and shown to be linear in the range of 25 microg/mL to 150 microg/mL for metformin and 0.1 microg/mL to 0.6 microg/mL for glimepride. The method is applied for the analysis of these analytes in commercially available tablets.     

反相高效液相色谱法同时测定咖啡豆中的6种酚酸类化合物

建立了同时测定咖啡豆中6种酚酸类化合物(咖啡酸、3-咖啡酰奎尼酸、4-咖啡酰奎尼酸、5-咖啡酰奎尼酸、3,5-二咖啡酰奎尼酸、4,5-二咖啡酰奎尼酸)的反相高效液相色谱测定方法。采用Kromasil C18柱(200 mm×4.6 mm, 5 μm),以乙腈和0.1%甲酸水溶液为流动相进行梯度洗脱,二极管阵列检测器检测,45 min内可对6种目标物进行同时检测,且各化合物都能达到基线分离。经测定,样品中6种酚酸类化合物的加标回收率为90.76%～104.73%,相对标准偏差为0.7%～3.9%。该法简便、快速、灵敏度高,适用于咖啡豆中6种酚酸类化合物的同时分析以及咖啡豆原料与制品的质量控制和综合评价。     

Simultaneous determination of serum cortisol and cortisone by reversed-phase liquid chromatography with ultraviolet detection.

A rapid high-performance liquid chromatographic (HPLC) method for the simultaneous determination of cortisol and cortisone in a single extract of 1 ml of serum is described. The method employs meprednisone as the internal standard. The steroids were analysed isocratically by reversed-phase HPLC with an octadecylsilane-bonded (ODS) column using ultraviolet detection. The matrix effect was reduced by lowering the sample pH by adding glacial acetic acid to the sera. The samples were then filtered through regenerated cellulose membranes at 4 degrees C and extracted with diethyl ether. The dried eluates were redissolved in the mobile phase and injected into the column. The detection limit of the assay for both steroids was 500 ng/l. Cortisol was determined in twenty serum samples by both HPLC and radioimmunoassay (RIA). The results were similar. Interference by other steroids and certain steroid analogue drugs was also studied. The HPLC method yielded no cross-reactivity between the different steroids as may occur with the RIA technique. The HPLC method was technically easy to perform and it allowed us to quantify both cortisol and cortisone in a single serum extract with high specificity.     

Simultaneous determination of reboxetine and O-desethylreboxetine enantiomers using enantioselective reversed-phase high-performance liquid chromatography

Current knowledge of stereoselective pharmacokinetics and different potencies of drug enantiomers requires the performance of stereoselective analysis during therapeutic drug monitoring in clinical practice. However, in the case of the new antidepressant drug reboxetine, no effort has been made so far to find a such a suitable system. Therefore, as a step towards developing an enantioselective bioanalytical method for reboxetine and the O-desethylreboxetine metabolite, three stereoselective chromatographic approaches have been investigated. Several chiral columns were tested, among them Chiral-AGP, ChiraGrom 2 and Chiral-CBH, which were able to simultaneously separate the two compounds into enantiomers in total running times of 28, 18 and 12 min, respectively.     

Simultaneous determination of four andrographolides in Andrographis paniculata Nees by silver ion reversed-phase high-performance liquid chromatography

A rapid and sensitive silver ion high-performance liquid chromatographic (Ag[I]-HPLC) method is developed for the simultaneous determination of the biologically active diterpenoids andrographolide, 14-deoxy-11,12-didehydroandrographolide, 14-deoxyandrographolide, and neoandrographolide in Andrographis paniculata Nees. HPLC is carried out for determining andrographolide and its derivatives with methanol-water (55:45, v/v) as the mobile phase on a C18 column (5 microm, 150 mm x 4.6 mm i.d.) with UV detection at 205 nm. Four andrographolides are baseline separated in a novel way: by adding silver ions (0.005 mol L(-1)) to the previously mentioned mobile phase. Validation of the method challenges specificity, linearity, limit of detection, limit of quantitation, accuracy, and repeatability, and the results met the acceptance criteria for all analytes. The molecular mechanism of retention is demonstrated by comparing partition coefficients (logP) of different andrographolides and andrographolide-Ag(I) complexes. Thus, the method is successfully applied to characterize and determine the four andrographolides in Andrographis paniculata Nees extract and its commercial product.     

Simultaneous determination of E-2-nonenal and beta-damascenone in beer by reversed-phase liquid chromatography with UV detection

A method for the simultaneous determination of E-2-nonenal and beta-damascenone in beer by reversed-phase liquid chromatography using UV detection is presented. The method consists of beer steam distillation, followed by an extraction/concentration step using Sep-Pak Plus C18 RP cartridges and determination by HPLC at 226 nm UV-absorption maximum. The identity of the compounds was confirmed by GC analysis with MS detection of the isolated fractions. A recovery factor of approximately 80% was obtained for beta-damascenone with a R.S.D. of 3%. E-2-Nonenal and beta-damascenone were monitored in a comparative study of fresh and either naturally and forced aged beer. The results obtained show that both compounds have a similar behaviour through an extended storage of beer and consequently can be used as good analytical markers of beer ageing. Nevertheless, the use of beta-damascenone seems to be more convenient because this compound appears in beer in higher concentrations than E-2-nonenal, thus making it easier to measure.     

反相高效液相色谱法同时测定罗氏海盘车中的7种核苷化合物

建立了罗氏海盘车中7种核苷化合物的反相高效液相色谱分析测定方法。采用超声波辅助提取,选用两根不同的C18色谱柱串联,以甲醇和0.2%(体积分数)乙酸/水溶液为流动相梯度洗脱分离。优化的色谱条件为: 柱温为室温,检测波长为260 nm,流速为0.8 mL/min,进样量为20 μL。结果表明,7种核苷化合物在一定的浓度范围内线性关系良好,次黄嘌呤和胸苷的线性范围为0.65～40 mg/L,尿苷、黄嘌呤和肌苷的线性范围为0.80～40 mg/L,胸腺嘧啶的线性范围为1.15～40 mg/L,鸟苷的线性范围为0.50～40 mg/L。样品中7种核苷化合物的加标回收率为90.00%～105.00%,相对标准偏差为0.72%～3.23%。该方法操作简便、灵敏度高、重复性好,回收率高,适用于罗氏海盘车中7种核苷类成分的同时分析,也可用于罗氏海盘车的质量控制和综合评价。