双指示物质动力学分析法研究Ⅰ.锰(Ⅱ)-乙二胺四乙酸二钠-铬(Ⅵ)催化体系

本文报道了双指示物质测定痕量锰的新催化光度法, 探讨了该方法的理论基础,确定了催化体系的适宜反应条件.本办法灵敏度比单指示物质法高6.4倍,用于测定谷物样品中锰.     

Studies on flow injection analysis of platinum metals: I. Flow injection catalytic determination of ruthenium by phthalin-hydrogen peroxide reaction

A new method has been developed for the determination of trace ruthenium by flow injection analysis. The proposed method is rapid, simple and sensitive. The method has a limit of detection for ruthenium of 0.020 μg/mL and permits 70 determinations per hour. The method has been applied to determine ruthenium in refined ore with satisfactory result.     

高效液相色谱法分离测定生物样品中吲哚类荧光化合物

本文提出一种用于吲哚类荧光化合物分离测定的高效液相色谱方法。本法采用２个洗脱液、固定柱温及荧光检测，检测灵敏度可达ｐｍｏｌ／Ｌ级，方法重现性良好。适用于生物样品中吲哚类荧光化合物的测定，样品不需复杂的预处理，因而或节省时间，避免样品中微量成份的损失。     

Titrations in non-aqueous media: Potentiometric method for determination of industrially important chloroanilines with perchloric acid in nitrobenzene solvent

A new potentiometric method to titrate some industrially important chloroanilines in nitrobenzene solvent with perchloric acid is described. The method was compared statistically with the classical diazotization method and shown to be significantly more accurate for two of the four compounds tested, with similar precision (RSD 0.4–0.8%). This comparison has revealed that the new method has some definite advantages over the classical diazotization method. The potentiometric method is also more rapid.     

混合溶剂火焰原子吸收法直接测定原油中的镍

混合溶剂火焰原子吸收法直接测定原油中的镍刘广东袁存光张丙华刘文钦（石油大学（华东），山东东营２５７０６２）彭力（中国石油天然气总公司环保处，北京１００７２４）关键词原油，混合溶剂，无机盐标准，原子吸收法，镍测定原油中，微量元素镍、钒、铁、铜的存在对...     

Bender–Wu formulas and classical trajectories: Higher dimensions and degeneracies

A method for the asymptotics of the perturbation series (Bender-Wu formulas) which is not restricted to one dimension is outlined. The method has a classical mechanic flavor and involves computing classical trajectories using classical perturbation methods. The method applies also when the unperturbed eigenvalues are degenerate. It is illustrated for the Hydrogen Zeeman Hamiltonian which is not separable and has degeneracies.     

Kinetic determination of cephalexin in drug formulations

A kinetic method for the accurate determination of cephalexin has been described. A solution of cephalexin is reacted with 5 x 10(-3)M cobalt(II) nitrate in 1 x 10(-3)M sodium hydroxide at 60 degrees C for a fixed time of 6 min, after which the absorbance of the reaction product is measured at 310 nm. The concentration of cephalexin is calculated by using the corresponding calibration equation for the fixed-time method. The method has been applied to proprietary drugs and the results were compared statistically with those given by the BP method. The determination of cephalexin by the fixed-concentration and rate-constant methods is feasible with the calibration equations obtained but the fixed-time method has been found to be more applicable.     

Iodometric determination of ascorbic acid by controlled potential coulometry

An iodometric method for the determination of ascorbic acid has been devised. The method is based on previously developed coulometric instrumentation. The stability of different ascorbic acid solutions has been studied and the best conditions have been established. Ascorbic acid has been determined in different kinds of samples but with the main interest on pharmaceutical preparations. Speqial regard has also been paid to the other constituents in such samples, with respect to possible interferences. The error of the coulometric method is about 0·1% and the time of an analysis is in the range 2–6 min.     

Jodimetric estimation of water-soluble dithiocarbamates

Summary Iodimetric estimation of dialkyl dithiocarbamate in alcoholic solution is not accurate. The method has not met with success for the water-soluble dithiocarbamates before. A simple and accurate iodimetric method has been developed for the estimation of water-soluble dithiocarbamates. The success of the method is due to the removal of the oxidation product which interferes during the titration with iodine.     

测定两干扰组分体系的新的吸光度图解法——定组分比推论法的研究

吸光光度法是广泛应用的一种方法,但在待测溶液中如果存在严重干扰的元素,方法将失效。本文试图从理论上研究出一种新的图解法.提出了测定两干扰组分体系的吸光度图解法--定组分比推论法。应用该法使用通常的分光光度计,不经分离或掩蔽,能在一种严重干扰元素存在下顺利地测定欲测元素的含量。本文从理论上研究了定组分比推论法的原理,并通过实验给以验证。它具有一定的普遍性,运用这种推理的方法,有可能扩大到其他领域。由于方法原理简单、无需特殊的仪器,故易于推广应用。     

测定痕量磷的激光热透镜光谱法--钼蓝法与孔雀绿法的比较

采用激光热透镜光谱法（LTLS）,分别以孔雀绿－磷钼杂多酸缔合物法和磷钼蓝法对痕量磷进行了测定;探讨了测定条件的影响,分析比较了两种测定方法,结果表明,钼蓝法的线性范围较宽,孔雀绿法的灵敏度较高,选择性较好,将孔雀绿LTLS法应用于河水、自来水和土壤样品中痕量磷的分析测定,取得了满意的效果。     

Determination of valproic acid by high-performance liquid chromatography with photodiode-array and fluorescence detection.

The derivatization of valproic acid and undecylenic acid with 4-bromomethyl-7-methoxycoumarin is described. The derivatives were detected by photodiode-array and fluorescence detectors. The optimum monitoring conditions and the stability of the suspension solution and derivatives were investigated. A high-performance liquid chromatographic (HPLC) method with isocratic or gradient elution has been established for the analysis. This method has been used for the determination of total and free valproic acid in serum. There is a satisfactory correlation between the results obtained by this HPLC method and those measured by the enzyme immunoassay. Some other common anti-epileptic drugs did not interfere with the analysis. The method is simple and fast and has better sensitivity and linearity than enzyme immunoassay. It is suited for routine therapeutic drug monitoring.     

茶叶中的铅

采用原子吸收汾光光度法对我国一些常用茶中Ｐｂ进行了测定，结果表明茶叶中的Ｐｂ通过一般食品，应引起重视。     

示波极谱-银量法的研究

示波极谱－银量法是以示波图形的突变来确定终点。其终点直观,不受溶液的颜色、沉淀、赋形剂的影响。可将重量分析变为滴定分析,具有准、快、简、省的特点,有广泛的应用前景。     

催化动力学褪色光度法测定痕量钒

基于磷酸和棉红在沸水发色条件下反应生成的产物在钒（Ⅴ）催化下被ＫＢｒＯ３氧化而建立了一个测定超痕量钒的新方法,方法选择性好;测定范围是０．００－０．７０μｇ／Ｌ,检测出限量７．３＊１０＾－１２ｇ／ｍＬ,方法用于芹菜、人体血清和井水中超痕量钒的测定,获得了满意结果。     

超临界流体干燥过程的分析

以ZrOCl2•8H2O为原料，采用超临界流体干燥（SCFD）法，在短时间内制备出大孔体积高比表面ZrO2气凝胶超细粉．该法具有良好的稳定性和可靠性．建立了醇凝胶中液相含水量的分析方法，为产品质量控制及确认体系是否处于超临界状态提供了依据．对抽提后的溶剂分析表明，SCFD过程是一物理过程．对水的抽提干燥过程亦进行了初步的理论探讨．     

Etude de la reaction de lactonisation de l'acide ethylenedioxy-1,1 methyl-2 oxo-3 cyclopentane-2- propionique

The lactonisation of ethylene 1,1-dioxy 2-methyl 3-oxo cyclopentane-2 propionic acid has been affected by a new method whose mechanism is discussed. The formation of a β-diketone and other products by isomerisation of the enol lactone has been avoided. The enol lactone is an important intermediate in the total synthesis of steroids and has been prepared with a good yield by the new method.     

An Improved Spectrophotometric Method for Determination of Penicillins Alone and in Pharmaceutical Dosage Forms

Abstract

A new spectrophotometric method for determining penicillins has been developed. A known volume of the penicillin solution is heated at 95[ddot]C for 70 min with ammonium molybdate, in sulphuric acid medium and the absorbance of the blue species formed is measured at 670 nm. The method has been successfully applied for the determination of thirteen commercially available penicillins. Beer's law is valid for up to 35-90 μg/ml of antibiotic (according to the penicillin). The procedure has been used for analysing some pharmaceutical preparations for these drugs, e.g., injections and capsules. The sensitivity of the method is largely increased with respect to the vanadate method previously described.     

Isotope fraction of hydrogen in hydrogen dichloride anions of tetramethyl- and tetraethylammonium salts

The theory of the double dilution method is shortly described. Critical volume of the liquid specimen has been determined. Optimal specimen concentration ratios of the sample in a given diluent have been examined. The validity and precision of the method have also been investigated. The usefulness of the method has been confirmed by analyzing a typical coin of Thailand. Good agreement with atomic absorption spectrometry (AAS) is obtained.