Third Order Derivative Molecular Absorption Spectrophotometry Determination of Traces of Samarium With Methyl Thymol Blue - CTAB or CPB

Abstract

A sensitive and selective method is described for the determination of traces of samarium by third order derivative molecular absorption spectrophotometry (TDMAS). The method is based on the formation of a stable, blue coloured water soluble ternary complex (Metal-Chromogenic reagent-surfactant) which is formed when cetyl trimethyl ammonium bromide or cetyl pyridinium bromide is added to binary samarium-methyl thymol blue system. The influence of various instrumental parameters and reaction conditions for maximum colour development is investigated. The ternary complex detection limit is 7.5 μg of samarium present in 25 ml of final solution. Linear calibration graphs are obtained for 0–30 μg of samarium. The relative standard deviation of the procedure was calculated to be 1.6%. Gd, Tb, Dy, Ho, Tm and Lu do not interfere in TDMAS determination of samarium. Methods are described for masking other interfering analytes.     

Simultaneous Determination of Perphenazine and Amitriptyline by Derivative Spectrophotometry

Abstract

Two methods have been developed for the simultaneous determination of Amitryptiline and Perphenazine: the zero-crossing (I) and the derivative ratio spectrum (II) methods and both use the derivative spectrophotometry.

The methods have been applicable in the ranges of 1 to 30 μg·ml^?1 of Amitryptiline (I and II) and between 1 and 8 μg·ml^?1 and from 1 to 7 μg·ml^?1 of Perphenazine for the methods I and II respectively. The accuracy of the proposed methods have been studied and they have been used in the determination of Amitryptiline and Perphenazine in commercially available pharmaceuticals.     

两次双波长分光光度法同时测定钼和钨的研究

本文把等吸收双波长法和双峰双波长法结合起来。建立了一种新型高灵敏度的同时测定铝、钨的两次双波长光度法。测定Mo、W的摩尔吸光系数分别为1.9×10~5和1.7×10~5L·mol~(-1).cm~(-1),测定范围1.5～8.0μg/25ml和4.0～15μg/25ml,相互允许量Mo:W=2:1～1:10,该法用于合成水样及标准钢样中的Mo和W的同时测定,结果满意。     

双波长分光光度法同时测定铌和钽

双波长分光光度法测定混合组分已被广泛应用,目前提出的有等吸收或K-系数双波长法、双显色双波长法及双峰双波长法等。由于铌钽性质相似,不易完全分离,已有人提出同时分析的方法。最近,文献报道了以5-Br-PADAP为显色剂用等吸收     

导数光度法同时测定五种食用合成色素

本文用一阶导数光度法研究了五种食用合成色素的吸光特性。选定五个波长测定五组份混合食用合成色素。十次测量的相对标准偏差<1.0％,标准回收在98％～103％以内。     

萃取催化光度法同时测定铁和铜

研究了在pH5.5的弱酸性介质,利用Fe(Ⅲ）、Cu(Ⅱ）对H2O2氧化邻氨基酚催化反应速率不同,用萃取平衡控制反应时间、水相中邻氨基酚的浓度和反应进行的程度,通过测量424nm下机要的吸光度,建立了萃取催化光度法同时测定铁和铜的新方法。其线性范围分别为0.0010-0.030mg/L和0.010-0.15mg/L。用于水、大豆和人发中铁和铜的测定,结果满意。     

一阶导数光谱K系数法同时测定硝基酚钠三组分

研究和建立了同时测定硝基酚钠混合三组份的新方法——一阶导数光谱K系数法。确定了最佳实验条件和测定波长,方法简便、快速、准确。通过对动植物细胞赋活增进剂中邻硝基酚钠、对硝基酚钠、5-硝基愈创木酚钠三组份的直接测定,其相对误差小于2%,相对标准偏差小于3%,回收率为99～103%。     

有机硅化合物中硅的原子吸收分光光度法测定

本文提供了一个简便、快速测定有机硅化合物中硅的方法。用氧瓶法分解试样(2-3 mg),用氢氧化钠和过氧化氢溶液为吸收液。样品溶解后,置于90℃水浴上加热半小时。冷却后,选择最佳原子化条件,用氧化亚氮/乙炔焰,采用标准加入法测定之。实验结果表明,对标准硅酸钠(Na_2SiO_3·9H_2O)中硅的测定,回收率为98.00～102.5％。吸收液氢氧化钠浓度为3N和6N时,对硅的定量测定均无影响,测定样品的相对误差<0.5％。     

石墨炉原子吸收光谱中氯化铕和硝酸铕背景吸收来源与特点的研究

研究了石墨炉原子吸收中氯化铕和硝酸铕背景吸收的来源、特点和消除方法。氯化铕背景吸收来源于其分解产物EuCl_2蒸气和Cl_2,而硝酸铕背景吸收来源于其分解产物NO和Eu_2O_3蒸气。测定铕中微量元素时,可通过选择灰化温度、记录原子吸收峰时间或加硝酸作基体改进剂等方法米减少、甚至完全消除背景吸收的干扰。     

Liquid-Liquid Extraction and Higher Order Derivative Spectrophotometric Determination of Cobalt with 1,10-Phenanthroline and Rose BENGAL

Abstract

Higher order derivative techniques are mainly used in deconvoluting the overlapping absorption spectra of various analytes in their determination. The procedure utilizing higher order derivatives in molecular absorption spectrophotometry essentially are based on the formation of binary complex viz. metal reacting with a chromogenic reagent. This paper reports a fourth order derivative spectrophotometric procedure for the determination of traces of cobalt based on the liquid-liquid extraction of ternary ion - asociation complex -cobalt, 1, 10-phenanthroline, rose bengal into chloroform. The developed procedure is simple, rapid, reliable and allows the determination of as low as 6 ppb of cobalt in high purity rare earth oxides and salts.     

卡尔曼滤波—紫外分光光度法同时快速测定4种嘌呤和嘧啶碱的含量

本文用卡尔曼滤波算法结合紫外分光光度法不经分离同时测定了腺嘌呤（Ａ），胸腺嘧啶（Ｔ），胞嘧啶（Ｃ），鸟嘌呤（Ｇ）４种含氮碱混合物中各成分的含量。测得模拟混合样品中各种碱的平均回收率范围１０１．８％－１０７．７％。也可用卡尔曼滤波算法鉴别别碱的种类。     

一阶导数分光光度法直接测定肉制品中硝酸盐及亚硝酸盐的含量

本文研究了硝酸盐及亚硝酸盐的一阶导数光谱，选择亚硝酸盐的一阶导数光谱与基线相交点２０７ｎｍ，作为硝酸盐的测定波长；选择硝酸盐在２０７ｎｍ、２２０ｎｍ处导数值相等，作为双波长法测定亚硝酸盐的测定波长。结果表明，硝酸盐及亚硝酸盐在１～１５μｇ／ｍＬ浓度范围内线性关系良好，合成样分析，加标回收试验，样品测定同标准比色法对照均获得满意结果。     

Indirect Determination of the Pesticide Malathion by Atomic Absorption Spectrophotometry

Abstract

A method for the indirect determination of the pesticide malathion by atomic absorption spectrophotometry (AAS) is proposed and compared with the standard spectrophotometric method.

A study of the influence of the different variables on the hydrolysis and extraction is carried out in order to obtain the best experimental conditions.

The proposed method offers clear advantages over the standard procedure because of the instability of the Cu (II) complex formed. Both methods are applied to the determination of malathion in two commercial formulations.     

Kalman滤波分光光度法用于同时测定废水中的钍及镧

近年来运用Kalman滤波(KF)分光光度法进行多组分同时测定,把干扰信息视作噪声,对相互叠加的光谱曲线作快速滤波,适用于多方程组联合运算,并可提高准确度[1～4]。本文以我室新合成的二溴羧基偶氮胂(3-[(4,6-二溴-2-羧基苯)偶氮]-6-[(2-胂酸基苯)偶氮]-4,5-二羟基-2,7-萘二磺酸)为显色剂,用KF分光光度法对工业废水实样中的钍(Ⅳ)及镧(Ⅲ)作     

原子吸收法测定某推进剂中铜含量的不确定度评定

对原子吸收分光光度法测定某推进剂中铜含量的测量不确定度进行了评定。对样品称量、试样溶液定容体积、曲线拟合、测量重复性等引入的不确定度分量进行了分析和量化,计算了合成不确定度。当推进剂中铜含量为0.96%时,扩展不确定度为0.08%(k=2)。     

火焰原子吸收光谱法间接测定非金属材料中氯

报道了火焰原子吸收光谱法（ＦＡＡＳ）间接测定非金属材料中氯的方法，采用ＡｇＣｌ沉淀，测定剩余Ａｇ~＋间接求出氯含量。方法的特征浓度为０．０１４ｍｇ／Ｌ（１％吸收），检出限为０．０３２ｍｇ／Ｌ（３），测定下限为０．１１ｍｇ／Ｌ，相对标准偏差（ＲＳＤ）为１．５％～１０％，样品加标准回收率在９１．４％－１０５％之间。     

卡尔曼滤波紫外光度法同时测定邻、间、对苯二酚

研究了苯二酚三种分异构体水溶液的紫外吸收光谱，在ＰＨ３．６的缓冲溶液中，邻、间、对苯二酚的紫我吸收峰分别为２７５ｎｍ，２７３ｎｍ和２８８ｎｍ三者重叠严重。选取在２４０ｎｍ－２９０ｎｍ范围内，每隔１ｎｍ测量一次吸光值截５１个点，采用卡尔曼滤波进行处理，可以获得较满意的结果，对１０个不同比例组成 标准混合液进行测定，邻、间、对苯二酚三者的平均回收率分别为９７．４％，１０１、７％和９８．０％，标准偏差分     

Determination of Mefenamic Acid and Paracetamol by First Derivative Spectrophotometry

Abstract

A direct and simple first derivative spectrophotometric method has been developed for the determination of mefenamic acid and paracetamol in pharmaceutical formulations. A methanolic hydrochloric acid solution was used as solvent for extracting the drugs from the formulations and subsequently the samples were evaluated directly by derivative spectrophotometry. Simultaneous determination of both drugs can be carried out using the zero-crossing and the graphical methods. The methods do not require simultaneous equations to be solved. The calibration graphs were linear in the ranges from 1.8 × 10^?6 to 1.6 × 10^?4 M of mefenamic acid and from 4.1×10^?6 to 1.4 × 10^?4 M of paracetamol. The ingredients commonly found in commercial pharmaceutical formulations do not interfere. The proposed method was applied to the determination of these drugs in tablets.