硫酸颜色反应用于荧光法测定利血平研究

提出了硫酸颜色反应用于利血平的荧光分析新方法。利用血平与浓硫酸反应，生成强荧光物质，所得产物的荧光强度与利血平的浓度在０－０．６μｇ／ｍＬ范围内有良好的线性关系。检测限为０．２ｎｇ／ｍＬ。本法可直接用于尿液中利血平的定量分析，回收率为８２．５％－８４．２％。     

流动注射化学发光法测定利血平

研究了利血平在酸性条件下与高锰酸钾和过氧化氢产生化学发光的行为，建立了流动注射化学发光测定利血平的新方法。利血平的浓度在１．０×１０＾－６￣８．０×１０＾－５ｈ／ｍＬ范围内与化学发光强度呈良好的线性关系；检出限为３×１０＾－７ｇ／ｍＬ。对６×１０＾－６ｇ／ｍＬ利血平进行１１次平行测定，得方法的相对标准偏差为１．３％。方法用于药剂中利血平含量测定，结果与药典标准方法测得值一致。     

荧光光谱法研究6—巯基嘌呤的氧化反应及其分析应用

系统地研究了高锰酸钾对６－巯基嘌呤的氧化作用,提出了高灵敏测定６－巯基嘌呤的荧光光度分析新方法。在碱性介质中,氧化产物的荧光强度较６－巯基嘌呤处身的荧光强度提高了１０倍,且稳定性好。本体系的激发波长为２８６ｎｍ,发射波长为３９７ｎｍ,荧光强度与６－巯基嘌呤的浓度在０．００６４～３．０μｇ／ｍＬ范围内呈线性关系,检测限为０．００３２μｇ／ｍＬ。应用该法于片剂中６－巯基嘌呤含量的测定,与标准方法对照,     

新—阶导数双峰光谱法解析及应用──测定NO_3~－和NO_2~－

本文通过对ＮＯ３－和ＮＯ２－的一阶导数光谱研究，提出利用它们各自导致光谱峰值的两种解析方法测定相互干扰的两组份含量，由于利用尽可能最大信息量和导数谱的特有功能，使测定ＮＯ３－和ＮＯ２－灵敏度分别为０．００５μｇ／ｍＬ、０．００９μｇ／ｍＬ（峰高－截矩比ｆ校正系数法）及０．００４μｇ／ｍｌ、０．００６μｇ／ｍＬ（双峰ｋ系组合导致法），线性范围皆为０～１．０μｇ／ｍＬ方法用于水样分析，结果令人满意。     

增敏荧光光谱法测定复方新诺明中的磺胺甲(口恶)唑

提出了在溴化十六烷基三甲铵（ＣＴＡＢ）存在下,ＰＨ为４．０的ＨＡｃ－ＮａＡｃ缓冲溶液中,增敏荧光光谱法测定复方新诺明中磺胺甲恶唑（ＳＭＺ）含量的新方法。碘胺甲恶唑浓度在０．０８－０．８μｇ／ｍＬ范围内,荧光强度与碘胺甲恶唑浓度呈良好的一性关系。方法的检出限为０．０１６μｇ／ｍＬ（６．３２＊１０＾－８ｍｏｌ／Ｌ）。方法已用于测定复方新诺明中磺胺甲恶唑的含量。     

水扬基荧光酮－溴化十六烷基三甲胺荧光熄灭法测定茶叶中的微量锰

本文研究了锰（Ⅱ）－水杨基荧光酮－溴化十六烷基三甲。在０．２１～１．６μｇ／２５ｍＬ范围内具有线性关系。检测限为０．２１μｇ／２５ｍＬ。本法灵敏度高，用于测定多种茶叶中的微量锰，结果满意。     

水扬基荧光酮—溴化十六烷基三甲胺荧光熄灭法测定茶叶中的微量锰

本文研究了锰（Ⅱ）－水扬基荧光酮－溴化十六烷基三甲，在０．２１～１．６μｇ／ｍＬ范围内具有线性关系。检测限为０．２１μｇ／２５ｍＬ。本法灵敏度高，用于测定多种茶叶中的微量锰，结果满意。     

催化极谱测定痕量铬的研究

本文研究了含氨介质中铬（Ⅲ，Ⅵ）－α，α－联吡啶－亚硝酸钠体系的电化学行为。建立了测定痕量铬的方法。测定铬的范围为０．００４－０．０２８μｇ／ｍＬ和０．０４－０．２８μｇ／ｍＬ，检测下限为２．０×１０＾－＾３μｇ／ｍＬ，用以测定生物样品中痕量铬，变异系数为９．８％。     

荧光法测定环境水中微量久效磷

采用荧光分光光度法测定了环境水中微量久效磷的含量。在０．２５％的吲哚丙酮溶液与０．２５％的过硼酸钠溶液的混合液中，体系温度为５℃时，λｅｘ／λｅｍ＝４２０ｎｍ／５００ｎｍ，检测限为４．０μｇ／Ｌ，线性范围为０－３．２μｇ／ｍＬ，回收率为９８％－１０４％，结果令人满意。     

饮料食品中Ge－132和Ge~（4＋）含量测定研究

本文报告了在０．０１ｍｏｌ／ＬＣＴＡＢ体系中，以Ｆ－为掩蔽剂、苯芴酮显色、用分光光度法测定饮料食品中Ｇｅ－１３２含量，最低检测限０．０５４μｇ／ｍＬ；线性范围０．５４～２７．１４μｇ／ｍＬ；回收率９６．３％～１０１．５％，并确定了Ｇｅ－１３２摩尔吸收系数（ε）３．３９×１０４。用本法测定了康寿茶、矿泉水和博士奶中Ｇｅ－１３２含量，灵敏度高、重现性和准确度好。用盐酸化本体系，研究了二氧化锗（Ｇｅ~（４＋））的含量测定，其最低检测限０．０２１μｇ／ｍＬ；线性范围１．０～２１．０μｇ／ｍｌ；回收率９５．８％～１０２．８％，Ｇｅ－１３２不干扰。饮料食品中同时存在Ｇｅ－１３２和Ｇｅ（４＋）时，本体系可分别测定两者含量。     

Flow injection spectrofluorimetric determination of reserpine in tablets by on-line acetone sensitized photochemical reaction

On-line photochemical reaction of reserpine in the presence of acetone was investigated. Acetone was found to speed up the on-line photochemical conversion of reserpine into an intensively fluorescent compound. Not only reaction acidity but also the acetate buffer concentration affected the on-line photochemical induced fluorescence signal. Based on the observation an automated flow injection photochemical fluorimetric approach was developed. An injected sample zone was carried by a water stream to be merged with a acetate buffer (pH 3.4) solution containing 0.02% acetone in a knotted PTFE reactor (KR), which was freely coiled around a 6-W low pressure mercury lamp. While passing the KR, reserpine was transformed into an intensively fluorescent compound. It was on-line detected in a flow-through cell at the emission wavelength of 490 nm and excitation wavelength of 386 nm. At optimized conditions, a detection limit 0.45 mug l(-1) was achieved at a sampling rate of 90 h(-1). Eleven determinations of a 0.5 mg l(-1) reserpine standard solution gave a R.S.D. of 0.3%. The linear dynamic range of reserpine calibration curve was 0.01-0.75 mg l(-1). The proposed method was applied to assay the reserpine content in tablets and to monitor the dissolution profile of reserpine tablets. Satisfactory results were obtained for both the assays and dissolution studies.     

Fluorometric determination of reserpine in dosage forms

A rapid and highly sensitive fluorometric procedure has been developed for the routine determination of reserpine, in bulk and in dosage forms. The method is based on the fluorescence induced by oxidation of reserpine with hexa-amminecobalt(III) tricarbonatocobaltate in aqueous acetic acid. The oxidation product exhibits a greenish yellow fluorescence with its emission maximum at around 420 nm. The fluorescence intensity is a linear function of reserpine concentration over the range 0.01-0.24 mug/ml in the solution finally measured. The advantages and disadvantages of the proposed method are discussed, and its applicability to different formulations is demonstrated.     

Determination of Reserpine in Plasma Using High-Performance Liquid Chromatography with Fluorescence Detection

Abstract

A high-performance liquid chromatographic method for determining reserpine in plasma has been developed. The procedure involves extraction of reserpine from buffered plasma into benzene, oxidation of reserpine to a fluorophor by treatment with vanadium pentoxide in phosphoric acid, and chromatographic separation of the reserpine fluorophor on an octadecylsilane column by ion-pairing with heptanesulfonate ions. Fluorescence monitoring of the column effluent provides high sensitivity of detection and increases the specificity of the procedure. A detection limit of approximately 100 pg of reserpine per ml of plasma was obtained following analysis of 2 ml samples. Analysis of a number of samples demonstrated the applicability of this method in confirming the presence of reserpine in equine plasma specimens collected at various horse shows and in evaluating the pharmacokinetic behavior of reserpine following intramuscular administration to horses.     

Sensitive Adsorption Stripping Voltammetric Determination of Reserpine by a Glassy Carbon Electrode Modified with Multi-Wall Carbon Nanotubes

Adsorption stripping voltammetry, a very sensitive electroanalytical method, was employed to determine reserpine, a kind of anti-hypertensive drug. In 0.1M phosphate buffer with a pH of 6.0, reserpine was accumulated at a multi-wall carbon nanotubes (MWNT)-modified glassy carbon electrode (GCE) surface under the condition of open-circuit. In the following anodic sweep from 0.20 to 1.00V, reserpine, adsorbed at the MWNT-modified GCE surface, was oxidized and yielded a sensitive oxidation peak at 0.64V. Due to its unique structure and extraordinary properties, MWNT shows a ten times higher accumulation efficiency toward reserpine, compared with a bare GCE. Hence, the amount of reserpine at the MWNT-modified GCE surface increases significantly, and finally the oxidation peak current improves greatly. The experimental conditions, such as supporting electrolyte, pH value, the amount of MWNT-DHP suspension, accumulation time and scan rate, were optimized for the measurement of reserpine, and a sensitive electroanalytical method was proposed for reserpine determination. The oxidation peak current varies linearly with the concentration of reserpine over the range of 2×10^–8 to 1×10^–5M, and the detection limit is 7.5×10^–9M after 4min open-circuit accumulation. The relative standard deviation at 1×10^–6M reserpine was about 4.7% (n=7), indicating excellent reproducibility. This new method was successfully demonstrated with reserpine injections and tablets.     

HPLC-Methods for Separation and Quantitation of Reserpin and its Main Degradation Products

Abstract

An analytical method suitable for the stability control of dosage forms containing reserpine by HPLC is described. Besides reserpine the method quantitatively determines isoreserpine, 3,4-didehydroreserpine, trimethoxybenzoic acid, and renoxidine. The additional degradation products reserpic acid, and the secondary oxidation product 3,4,5,6-tetradehydroreserpine are qualitatively recorded.     

Spectrophotometric determination of Rauwolfia alkaloids: estimation of reserpine in pharmaceuticals.

A simple, sensitive and economically viable spectrophotometric method for the determination of some Rauwolfia alkaloids (ajmaline, ajmalicine, reserpine and yohimbine-HCl) has been developed. The method involves the oxidation of Rauwolfia alkaloids by iron(III) and subsequent complexation of iron(II) with 1,10-phenanthroline, forming a red-colored complex having the maximum absorbance at 510 nm. The method is applied to the determination of reserpine in tablets of pharmaceutical formulations. The common excipients do not interfere with the proposed method. A statistical comparison of these results with those of a reported method shows good agreement and indicates no significant difference in the precision.     

An Improved Method for the Determination of Reserpine in Plasma Using Liquid Chromatography with Fluorescence Detection

Abstract

A liquid chromatographic method coupled with fluorescence detection was developed to measure plasma reserpine concentrations. After extraction from 3 ml of plasma, the reserpine and internal standard (methyl-18-triethoxy benzoyl reserpate) residues were oxidized to their respective fluorophors by vanadium pentoxide and chromatographed on a reversed phase trimethylsilyl column. These compounds were detected at excitation wave length 460 nm and analyzed at 570 nm. The minimum quantifiable level was ca 0.3 ng/ml and the absolute recovery was determined to be between 78–83%. The coefficient of variation was less than 9% for day-to-day and within run analyses. This method is suitable for pharmacokinetic studies of reserpine in man.     

利血平与玫瑰精B的高灵敏显色反应及分析应用

研究了利血平与玫瑰精B的显色反应,建立了测定利血平的高灵敏分光光度法。在酸性条件下,利血平的水解产物和玫瑰精B形成具有正、负吸收峰的红色离子缔合物,最大正吸收波长位于490 nm,最大负吸收波长位于520 nm,表观摩尔吸光系数(ε)分别为1.20×105L.mol-1.cm-1(正吸收)和1.83×105L.mol-1.cm-1(负吸收),利血平在0～5.0μg/mL范围内遵从比尔定律。若采用正、负峰叠加测定,灵敏度可达3.00×105L.mol-1.cm-1。探讨了适宜的反应条件、主要分析特性及方法的精密度和可靠性。该法可用于市售利血平注射液中利血平含量的测定。     

Continuous-flow determination of reserpine by oxidation with periodate ion and catalysis by manganese(II) in solution or by an MnO2(s) reactor

The periodate ion oxidation of reserpine catalyzed by Mn(II) or Mn(IV) ions was used for the continuous-flow determination of the pharmaceutical drug. Spectrophotometric monitoring of the oxidation product, 3,4-didehydroreserpine, at 385 nm served as means of detection. The Mn(II) catalyst was used in solution and the Mn(IV) in immobilized form as crystalline MnO₂(s) was thermally embedded on the walls of Tygon tubing and incorporated in the flow system as a solid catalyst in an open-tubular reactor. The proposed methods were applied to the analyses of single tablets and of Rauwolfia serpentina standard powders.     

High Performance Liquid Chromatographic Determination of Diuretic-Antihypertensive Combination Products. II. Polythiazide and Reserpine

Abstract

A high performance liquid chromatographic method for the simultaneous determination of polythiazide and reserpine in tablets is described. Polythiazide, reserpine, and vanillin (an excipient) are separated isocratically on an octadecylsilane column using a methanol-water-acetic acid (55:44:1) mobile phase. The column effluent was monitored by ultraviolet ab-sorbance at 254 nm. Recoveries from synthetic formulations were 100.2 ± 1.7% for polythiazide and 98.7 ± 1.1% for reserpine.