溴甲酚绿分光光度法测定麻黄碱含量的研究

建立了溴甲酚绿分光光度法测定麻黄碱的方法。该方法最大吸收波长为620nm,摩尔吸光系数为1.78×104L.mol-1.cm-1,盐酸麻黄碱含量在20~120μg/mL范围内遵守比耳定律。用该法测定麻黄饮片及麻杏止咳片中的麻黄碱,平均回收率分别为98.9%、101.2%(n=3),相对标准偏差(RSD)<2.31%。方法简单、快速,适用于生药及产品的质量控制。     

Cerimetric determination of triphenylmethane dyes

Summary The cerimetric determination of the carbinol bases of crystal violet, magenta, and ethyl violet is described. Best results are obtained by applying reverse titration.

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Zusammenfassung Die Carbinolbasen von Kristallviolett, Fuchsin und Äthylviolett werden cerimetrisch bestimmt. Die besten Ergebnisse erhält man bei umgekehrter Titration.

     

Cerimetric determination of dithionate and polythionates

Ceric sulphate in a boiling strongly acidic medium oxidizes dithionate as well as tri- and tetrathionates quantitatively to sulphate. These anions may therefore be determined cerimetrically when they are present singly. A combination of the cerimetric method with other known methods (e.g. those of Kurtenacker, etc) is suggested for the analysis of mixtures of polythionates and dithionate.     

Cerimetric determination of mercury (I)

Summary A new cerimetric procedure has now been developed for the direct volumetric titration of mercury (I) to an iodine monochloride end point. This new method has the advantages, (1) it gives a direct titration, (2) the determination can be made at the room temperature and (3) the method does not involve any correction factors.The authors wish to express their grateful thanks to the Ministry of education, Government of India, for the award of a Research Scholarship and the authorities of the Andhra University for providing research facilities.     

Determination of Ephedrine via the Formation of Metal Complexes

Abstract

The reaction of ephedrine with carbon disulphide and metals'reagents (nickel, copper and cobalt has been studied. Various methods are accordingly introduced for the determination of ephedrine in pure form and in pharmaceutical formulations. Direct spectrophotometric method determines 0.24-1.21, 0.61-5.45 and 6.05-60.5 μ moles. of epherdrine with a mean accuracy (P'=0.05) of 100.24± 1.48%,99.65±1.68% and 99.73±0.59% using nickel, copper and cobalt respectively. Indirect determinations- through the metals' content- include atomic absorption method, which is suitable for the determination of 0.73-8.5, 1.82-6.66 and 3.63-24.2 μ moles. of ephedrine with a mean accuracy of 99.49±1.18%, 100.13±1.65% and 99.68±0.63% on using nickel, copper and cobalt respectively. The corresponding data on determining the metals by the oxalyldrazide method are : 1.45-16.94, 0.61-1.57 and 0.73-17.54 μ moles. of epherdrine, 99.13±0.6%, 99.35±0.71% and 99.54±0.73% on using nickel, copper and cobalt respectively.     

Cerimetric determination of thallium (I)

Summary The cerimetric determination of thallium(I) has been reinvestigated. A new procedure for the potentiometric titration of thallium(I) with ceric sulphate at the room temperature and at a low concentration of hydrochloric acid (1.0 N) has been developed using iodine monochloride as catalyst.The authors wish to express their grateful thanks to the Ministry of Education, Government of India, for the award of a Research Scholarship and the authorities of the Andhra University for providing research facilities.     

气相色谱-质谱测定保健食品中的麻黄碱和伪麻黄碱

麻黄为麻黄科植物,是一种传统中药,含苯烃基胺类生物碱,主要为麻黄碱、伪麻黄碱和微量l-N-甲基麻黄碱、d-N-甲基伪麻黄碱、d-去甲伪麻黄碱等,用于治疗风寒感冒、胸闷喘咳、风水浮肿、支气管哮喘^[1]。同时它也有毒副作用,国际奥委会把它列为禁用药品,许多国家禁止其在食品、保健品中使用。测定麻黄碱的方法已有很多^[2-5],但具有各自     

Cerimetric determination of metals forming pyridine thiocyanate complexes

Summary A new procedure for the quantitative determination of Cu, Co, Ni and Cd has been described. It is based on the precipitation of the metals as pyridine thiocyanate complexes and titrating the excess thiocyanate with ceric sulphate using dead stop end point method or the usual visual end point method with vigorous stirring.

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Zusammenfassung Ein neues Verfahren zur Bestimmung von Kupfer, Kobalt, Nickel und Cadmium beruht auf der Fällung der Metalle als Pyridinthiocyanatkomplex und Rücktitration überschüssigen Thiocyanats mit Cer(IV)-sulfat. Der Endpunkt kann nach der Dead stop-Methode oder visuell bestimmt werden.

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See also Z. analyt. Chem. 185, 376 (1962).

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Authors thanks are due to Prof. G. B. Singh for the facilities provided during the above work. The award of a fellowship by U.G.C. to one of us (A.L.J.R.) is also acknowledged.     

离子对色谱法测定麻杏石甘汤中的麻黄碱和伪麻黄碱

麻杏石甘汤出自《伤寒论》,由麻黄、杏仁、甘草和石膏四味中药组成。麻黄主要含麻黄碱和伪麻黄碱,两者是麻杏石甘汤中的主要有效成分。对麻黄及其制剂中的麻黄碱和伪麻黄碱含量测定的方法主要有高效液相色谱法（HPLC）、高效毛细管电泳法和气相色谱-质谱联用法等。由于麻黄碱和伪麻黄碱结构相似,而且生物碱容易产生拖尾现象,采用反相高效液相色谱法一般难以使两者达到良好的分离。本文采用反相离子对HPLC使两者获得了良好的分离,并以此法对麻杏石甘汤中的麻黄碱和伪麻黄碱进行了测定。     

碳纳米管修饰电极离子色谱电化学法测定盐酸麻黄碱

采用阴离子交换分离,碳纳米管修饰电极安培检测离子色谱电化学法测定盐酸麻黄碱.在优化条件下,用碳酸钠溶液和甲醇溶液混合溶液为淋洗液,用碳纳米管修饰玻碳电极,在0.8 V电位处进行直流安培检测.结果发现在碳纳米管修饰玻碳电极后盐酸麻黄碱的电流响应值比未修饰前大大增加,方法的灵敏度比未修饰电极提高了10倍,用未修饰电极测定的检出限为2.4 μg·L-1,用修饰电极测定的检出限为0.2 μg·L-1,样品加标回收率为103.6%..     

毛细管电泳-方波安培法分离检测滴鼻液中的麻黄碱

在熔融石英毛细管 (75mm× 5 0cm )中 ,以 5mmol/LTris(三羟甲基氨基甲烷 ) +5mmol/LH3 BO3(pH =6 .5 )为电泳介质 ,采用毛细管电泳 方波安培检测法 ,实现了滴鼻液中盐酸麻黄碱的分离检测。探讨了缓冲溶液的种类、浓度、pH值、检测电位等因素对分离检测效果的影响。线性范围为 0 .8～ 2 0 2mg/L ,检出限为 0 .3mg/L ,回收率为 92 %～ 10 4 %。     

毛细管电泳-电致化学发光法同时测定鼻炎康片中马来酸氯苯那敏和盐酸麻黄碱

基于马来酸氯苯那敏(Ch)和盐酸麻黄碱(Ep)同时增强联钌吡啶的电致化学发光信号特性,利用Ch和Ep在毛细管电泳分离时组分保留时间的差异,建立了毛细管电泳-时间分辨电致化学发光同时在线检测鼻炎康片中Ch和Ep含量的新方法。实验表明,在保持初始电位1.20V、运行高压为15kV、pH为10.5的NaH_2PO_4-Na2HPO_4缓冲液(添加10%乙腈和5%甲醇)的分离条件下,以及工作电极电位为1.2V、电动进样13kV和进样时间10s、pH=8的磷酸盐作为运行缓冲液的检测条件下,Ch和Ep在6min内可实现分离与检测,其线性范围分别为2.0×10~(-7)~2.0×10~(-4) mol/L和3.8×10~(-7)~6.0×10~(-4) mol/L,检出限分别为4.0×10~(-8) mol/L和1.5×10~(-8) mol/L(n=11),迁移时间的RSD分别为1.9%和2.2%,方法的RSD分别为3.9%和4.6%,方法回收率分别为97.97%和95.23%。     

乳液电导法对麻黄中麻黄碱和伪麻黄碱的分步检测

使用水－界面膜－油体系通过物质具有不同的酸离解常数及透膜常数以提高电导滴定方法的选择性,对麻黄草中的混合生物碱进行了分步测定,终点明确。盐酸麻黄碱回收率９９．８％±０．８％。麻黄草中麻黄碱含量０．４１％、伪麻黄碱０．１０％,其余生物碱０．０６％,生物碱总量０．５８％,与ＨＰＬＣ法结果总体一致。     

Cerimetric determination of uranium Use of triphenylmethane dyes as internal indicators

The use of the triphenylmethane dyes (erioglaucine, eriogreen, and xylene cynol FF) as internal indicators in the cerimetric titration of uranium^IV has been investigated. The titration is possible in the cold with sufficient rapidity and accuracy, the indicator colour change appearing sharply at the equivalence point. The indicator reactions are rapid and reversible within a wide range of acidity, from 0.5N to 8.0N, unlike other indicators, e.g. diphenylbenzidine, -phenylanth-ranilic acid or ferroïn, which require specified conditions for their proper functioning. These indicators can also beused for titration of uranium^IV with eerie ammonium nitrate in perchloric acid medium (but not in nitric acid medium).     

Determination of Ephedrine, Pseudo-Ephedrine and Caffeine in a Dietary Product by Capillary Electrophoresis

This paper reports the determination of caffeine, ephedrine and pseudo-ephedrine in a dietary product by two rapid and simple methods utilising capillary electrophoresis (CE). The solutes were extracted from the product using 0.2 M HCl and determined by CE with background electrolytes containing 7.5% highly sulfated-β-cyclodextrin (7–11 sulfate groups per β-CD molecule) at pH 2.5 and pH 7.6. Determination of ephedrine and pseudo-ephedrine was accomplished at pH 2.5 with the anode at the detection side of the capillary whereas caffeine was quantified at pH 7.6 with a normal electrophoresis polarity mode. Triethanolamine was added to the running buffer at pH 2.5 in order to reverse the electroosmotic flow (EOF) and thereby speed up the separation of ephedrine and pseudo-ephedrine. Revised: 18 November 2005 and 2 January 2006