反相高效液相色谱法同时测定桑叶提取物中芸香甙和槲皮素的含量

用Ｐ１００型高效液相色谱系统、ＤＬ－８００色谱工作站、ＹＷＧ－Ｃ１８色谱柱,以甲醇－水－磷酸体系（６０∶４０∶０．４,Ｖ／Ｖ／Ｖ）为流动相分离并同时测定了桑叶提取物中芸香甙与槲皮素的含量。芸香甙、槲皮素含量与峰面积呈良好的线性关系。芸香甙的变异系数为１．９８％,回收率为１０４．０％;槲皮素的变异系数为９．８％,回收率为１０３．２％。     

快速测定蜂王浆中蜂王酸的分光光度法研究

本文提出了用差示分光光度法和一阶导数分光光度法测定蜂王浆中蜂王酸的含量，差示光谱最大测定波长为（＋）２２８．０ｎｍ；一阶导数光谱测定波长为（＋）２０４．５ｎｍ和（－）２３３．５ｎｍ。线性范围为０－２０μｇ／ｍｌ（差示分光光度法）和０－１５μｇ／ｍｌ（一阶异数分光光度法）。二法在实际测定中具有操作简便，快速和准确度高等优点。     

涂碳型PVC膜氧氟沙星选择电极的研制与应用

报道了一种以氧氟沙星碘化物与碘化铋的分子缔合物为电活性物的新型涂碳ＰＶＣ膜氧氟沙星选择电极．电极的能斯特响应范围为１．０×１０－５～３．２×１０－２ｍｏｌ／Ｌ，斜率为３１ｍＶ／ｐＣ，电极响应迅速，重现性好．用此电极对药片中的氧氟沙星进行测定，结果与紫外分光光度法相符．     

贯叶金丝桃提取物中总黄酮的测定方法

以中药材 贯叶金丝桃的提取物为对象 ,对其主要有效成分黄酮类化合物总含量测定的几种分光光度法进行了比较研究。发现文献中某些常用的分光光度法存在严重的缺陷。通过与高效液相色谱法测定结果比较 ,建立了一种测定总黄酮含量的分光光度法     

PVC 功能膜固相反射分光光度法测定矿样中镉

提出了用ＶＰＣ功能膜固相反射分光光度法测定矿样中镉,在弱碱性介质中,镉与均匀分布在ＰＶＣ功能膜上的吡啶偶氮萘酚定量反应,在自制的固相反射分光光度计附件上测定。镉质量浓度在０－０．５μｇ／ｍＬ范围内,ＡＲ与ｃ有良好的线性关系,同限为０．０１５μｇ／ｍＬ,相对标准偏差为１．４％（对于２．０μｇＣｄ,ｎ＝１１）,方法已用于矿样中镉的测定。     

超临界流体色谱法测定银杏叶提取物中的黄酮类化合物

采用超临界流体色谱法分离测定了银杏叶提取物水解后的三个甙元－－槲皮素、山奈酚、异鼠李素的含量。以苯基柱为固定相,二氧化碳－乙醇－磷酸９０：９．９８：０．０２Ｖ／Ｖ）为流动相,三个黄酮甙元获得良好的分离,利用各甙元的转换因子计算了黄酮化合物的总黄酮的含量,这种方法定量结果准确,重现性好。     

同时测定合成样中铜钴镍钒含量的分光光度法--主成分回归法和偏最小二乘法比较

研究了主成分回归和偏最小二乘方法在多组分分光光度法分析中的应用,以５－Ｂｒ－ＰＡＤＡＰ（２〔５－溴－２－吡啶）－偶氮〕５－二乙氨基苯酚）为显色剂,ＯＰ（聚乙二醇辛基苯基醚）作为增溶增稳剂,在ｐＨ＝３．６的条件下,用主成分回归及偏最小二乘分光光度法同时测定了合成样中的铜、钴、镍、钒４组分含量,测定相对误差在－６．００％～４．００％之间。实验证明,对于加和性不好的体系偏最小二乘分光光度法要优于主成分回     

高效液相色谱法测定环境水中痕量4,4′-二氨基联苯、4-硝基酚和苯酚

采用ＰｈｅｎｏｍｅｎｅｘＳｐｈｅｒｅｘＣ１８色谱柱,以含５０ｍｍｏｌ／Ｌ乙酸－乙酸钠缓冲溶液（ｐＨ６．０）的Ｖ（乙腈）∶Ｖ（乙醚）∶Ｖ（水）＝１２∶１０∶７８混合溶液为流动相,用分光光度法检测,检测波长为２７５ｎｍ,在１６ｍｉｎ内实现了４,４′－二氨基联苯、４－硝基酚和苯酚的同时分离测定。检测限分别为０．１４,０．１９和０．０８ｎｇ。标准回收率分别为９８．８５％,９８．１５％和９８．１０％。方法灵敏度高,用于环境水样分析时结果令人满意。     

贯叶金丝挑提取物中总黄酮的测定方法

以中药材-贯叶金丝桃的提取物为对象,对其主要有效成分黄酮类化合物总含量测定的几种分光光法进行了比较研究。发现文献中某些常用的分光光度法存在严重的缺陷。通过与高效液相色谱法测定结果比较,建立了一种测定总黄酮含量分光光度法。     

乙二胺四乙酸对锗（Ⅳ）—没食子酸体系及钒（Ⅳ）的示波极谱电流的影响

用分光光度法及电化学法详细研究了在稀硫酸介质，分别加ＥＤＴＡ到锗－没食子酸，Ｇｅ－ＧＡ－Ｖ体系以及Ｖ溶液中，所产生的影响。结果表明，ＥＤＴＡ使Ｇｅ－ＧＡ体系的两步２电子反应过程变得清Ｇｅ－ＧＡ－Ｖ体系因Ｖ２Ｈ３Ｙ＾－Ｇ形成，增强了Ｖ的化学氧化力。     

A rapid and sensitive determination of aucubin in rat plasma by liquid chromatography-tandem mass spectrometry and its pharmacokinetic application

A sensitive, accurate, rapid and robust LC‐MS‐MS method for the quantification of aucubin, a major bioactive constituent of Aucuba japonica, Eucommia ulmoides and Plantago asiatica, was established and validated in rat plasma. Plasma samples were simply precipitated by adding methanol and the supernatant was chromatographed by a Diamonsil® C₁₈(2) column with the mobile phase comprising a mixture of 10 mm ammonium acetate in methanol and that in water with the ratio of 50:50 (v/v). Quantification of aucubin was performed by mass spectrometry in the multiple‐reaction monitoring mode with positive atmospheric ionization at m/z 364 → 149 for aucubin, and m/z 380 → 165 for catalpol (IS), respectively. The retention time was 2.47 and 2.44 min for aucubin and the IS, respectively. The calibration curve (10.0–30,000 ng/mL) was linear (r² > 0.99) and the lower limit of quantification was 10.0 ng/mL in the rat plasma sample. The method showed satisfactory results such as sensitivity, specificity, precision, accuracy, recovery, freeze–thaw and long‐term stability. This simple LC‐MS method was successfully applied in a pharmacokinetic study carried out in Sprague–Dawley rats after oral administration of aucubin at a single dose of 50 mg/kg. Herein the pharmacokinetic study of aucubin is reported for the first time. Copyright © 2011 John Wiley & Sons, Ltd.     

Extraction of iridoid glycosides and their determination by micellar electrokinetic capillary chromatography

Several methods for the extraction of two iridoid glycosides, catalpol and aucubin, from the plant matrix (Veronica longifolia leaves) were compared. Pressurized hot water extraction and hot water extraction were the most efficient isolation techniques for both. Pressurized liquid extraction and maceration with various organic solvents were also tested. Relative to the amounts extracted with hot water, ethanol extracted only 22% of catalpol and 25% of aucubin and pressurized hot water extracted 83% of catalpol and 92% of aucubin. The lowest relative standard deviations, 22% for catalpol and 8% for aucubin, were achieved with hot water extraction (13 repetitions), and the highest relative standard deviations, 76% for catalpol and 73% for aucubin, with pressurized liquid extraction (five repetitions). A fast capillary electrophoretic method was developed for the quantitative determination of catalpol and aucubin.     

Determination of iridoid glycosides in larvae and adults of butterfly<Emphasis Type="Italic"> Melitaea cinxia</Emphasis> by partial filling micellar electrokinetic capillary chromatography—electrospray ionisation mass spectrometry

The iridoid glycosides, methyl catalpol, asperuloside, verbenalin, cinnamoyl catalpol, catalpol and aucubin, were studied from both larvae and adults of butterfly Melitaea cinxia. Special emphasis in the study was put on finding a correlation between the iridoid glycoside content in butterflies and plants. An optimised partial filling micellar electrokinetic capillary chromatographic–electrospray ionisation mass spectrometric (PF-MECC-ESI-MS) method was employed for the separation and identification of the six iridoid glycosides. In this work, the isolation and determination of catalpol and aucubin from extracts of both larvae and adults of Melitaea cinxia butterflies is demonstrated. The PF-MECC-ESI-MS method, using the [M+Na]+, [M+Li]+ and/or [M+NH₄]+ adducts in ESI-MS, was used for quantification of aucubin and catalpol in the insects. In addition, the identification of all analytes was attempted by direct infusion MS/MS analysis. LOQ values for the iridoid glycosides varied between 10 mg/l (for verbenalin) to 50 mg/l (for catalpol and aucubin) corresponding to 0.1% of the sample´s dry mass. A correlation was noticed between the concentrations of iridoid glycosides in plants and the concentrations in larvae feeding on them.     

Simultaneous Analysis of a Mixture of Iridoids in Water Extracts of Plantago asiatica L. by LC

A simple liquid chromatographic method using an ultraviolet detector was developed for the simultaneous quantification of a mixture of iridoid glycosides, catalpol, aucubin, and geniposidic acid. By adding a minute amount of trifluoroacetic acid into the conventional aqueous acetonitrile mobile phase, the unstable resolution arising from the tautomeric rearrangements in the carboxylic group at the 11 position of geniposidic acid could be solved, resulting in a clear separation profile of the catalpol, aucubin, and geniposidic acid peaks. We were able to quantify the contents of catalpol, aucubin, and geniposidic acid contained in the leaves and seeds of P. asiatica.     

Application of the vanadium(V)-xylenol orange reagent to the assay of serum glucose

The VXO reagent (mixture of V(V) and xylenol orange) provided in our earlier studies is found very useful for the colorimetric determination of traces of hydrogen peroxide. In this paper the reagent is successfully extended to the assay of glucose in serum by the combined use of glucose oxidase.The VXO reagent exhibited a characteristic absorption maximum at 582 nm, and the presence of glucose together with glucose oxidase led to a significant decrease in the absorbance of the reagent. A linear relation was found between the magnitude of the decrease and glucose concentration in the range of 5 to 400 mg/100 ml. The average recovery of glucose added in serum was 98.6% and the data were reliable with a coefficient of variation below 3.0%. A good correlation to the method by 4-aminoantipyrine-phenol was found: r = 0.970. Ascorbic acid and uric acid did not interfere with the assay.     

A New Iridoid Glucoside from Lagotis yunnanensis

Phytochemical investigation of Lagotis yunnanensis led to the isolation andidentification of a new iridoid glucoside 1, named as 10-O-(3, 4-dimethoxy-(E)-cinnamoyl)aucubin.Its structure was elucidated by spectroscopic methods.     

Determination of Trace Amounts of Vanadium by Kinetic-Catalytic Spectrophotometric Methods

Kinetic-catalytic spectrophotometric methods were proposed for the determination of trace amounts of vanadium element as vanadium（Ⅳ） and/or V（Ⅴ） ions. The vanadium（Ⅳ） as VO^2＋ ion and/or vanadium（Ⅴ） as VO3^- ion showed a catalytic effect on the kinetic reactions between a color reagent such as methylthymol blue （MTB） or SPADNS and bromate in acidic media. The rate of decrease in the absorbance of the reagent MTB at 440 nm or SPADNS at 510 nm was proportional to concentration of V（Ⅳ） and/or V（Ⅴ） ions in the solution. The linear ranges for determination of vanadium were obtained in the range of 1.0-150 and 5.0-100.0 μg/L by the fixed-time and slope methods, respectively, with using MTB as reagent. In the presence of SPADNS as reagent, the calibration curves were made in the amplitude 1.0-200.0 and 5.0-150 μg/L of vanadium ion by the fixed-time and slope methods, respectively. Using fixed-time method, the limits of detection were obtained to be 0.5 and 0.7 μg/L of vanadium in the presence of MTB and SPADNS as reagents, respectively. Detection limits of vanadium by slope method and reagents of SPADNS and MTB were obtained to be 3.5 and 3.8 μg/L of vanadium, respectively. The proposed methods were applied successfully to determination of vanadium in synthetic and real samples.     

Use of the vanadium(V)-xylenol orange mixture as an improved reagent for the spectrophotometric determination of traces of hydrogen peroxide

The reaction in V(V)-xylenol orange (XO)-H₂O₂ system was studied by spectrometry. On the addition of hydrogen peroxide to the mixture of vanadium(V) and XO (V-XO reagent), the absorption peak of V(V)-XO complex (λ_max = 582 nm) decreased significantly. The decrease in the absorbance (denoted as ΔA) was proportional to the concentration of hydrogen peroxide. The constant values of ΔA were obtained under the condition of [XO]/[V(V)] = 0.5 ~ 1.2 and in the pH 3.5 ~ 4.5 region. Based on these results, the conditions for the use of the V-XO reagent in the colorimetric determination of hydrogen peroxide were examined in detail. The V-XO reagent was found to be useful for the trace analysis of hydrogen peroxide with high sensitivity, and the data were little affected by the presence of some inorganic and organic substances. The lower limit of the determination is about 1 × 10^?6M.     

Simultaneous Analysis of a Mixture of Iridoids in Water Extracts of <Emphasis Type="Italic">Plantago asiatica</Emphasis> L. by LC

A simple liquid chromatographic method using an ultraviolet detector was developed for the simultaneous quantification of a mixture of iridoid glycosides, catalpol, aucubin, and geniposidic acid. By adding a minute amount of trifluoroacetic acid into the conventional aqueous acetonitrile mobile phase, the unstable resolution arising from the tautomeric rearrangements in the carboxylic group at the 11 position of geniposidic acid could be solved, resulting in a clear separation profile of the catalpol, aucubin, and geniposidic acid peaks. We were able to quantify the contents of catalpol, aucubin, and geniposidic acid contained in the leaves and seeds of P. asiatica.     

阿拉善马先蒿植物中单萜环烯醚甙的研究

阿拉善马先蒿(Pedicularis alaschania maxim)系玄参科马先蒿属植物,民间可代替夏枯草入药,主治淋巴结核、淋巴腺炎、高血压和甲状腺肿大等疾病。其化学成分研究尚未见报道。我们从马先蒿中分离得到2个单萜环烯醚甙P1和P2。P2经质谱(FAB MS)、核磁共振谱(~1H和~(13)C NMR)和红外光谱等数据与文献对照确定为桃叶珊瑚甙(aucubin)。P1为一新化合物。本文报道它们的分离与鉴定。