偶氮氯膦Ⅲ双波长分光光度法测定奶粉中的Fe(Ⅲ)

在酸性介质中,Fe(Ⅲ)与偶氮氯膦Ⅲ反应生成具有明显正吸收峰和负吸收峰的螯合物,最大正吸收波长位于670nm,最大负吸收波长位于530nm,用双波长叠加测定,表观摩尔吸光系数(ε)为5.93×10~4 L/(mol·cm),线性范围为0.2~2.00mg/L,探讨了适宜的反应条件、考察了准确度、精密度及选择性。该方法用于奶粉中Fe(Ⅲ)的测定,结果令人满意。     

双波长吸光光度法测定磷矿中氧化镁

以EGTA－Ba和SO4^2-为联合掩蔽体系，有效地消除因大量钙存在而产生的干扰。在PH10．2硼砂缓溶液中，镁与偶氮氯磷Ⅰ形成稳定络合物，用自制的双波长分光光度仪，在组合波长570nm和500nm下，用于磷矿中镁的测定。不需分离，方法简单，快速，结构满意。     

双波长叠加法测定样品中槲皮素含量

在pH= 7.45的B-R缓冲介质中,槲皮素在256 nm和368 nm波长处有两个强度不等的吸收峰,实验发现两个峰的吸光度值之和与槲皮素的浓度呈良好的线性关系,据此提出了双波长叠加分光光度法测定微量槲皮素的新方法.槲皮素的质量浓度在0.84～42 μg· mL-1范围内符合比耳定律,表观摩尔吸光系数高达4.24×10...     

碱性桃红探针吸收光谱法测定吡哌酸

建立了测定药物及生物样品中吡哌酸的单波长和双波长可见吸收光谱法。在可见光区和pH 6.63 Tris-HCl介质中,吡哌酸与碱性桃红反应生成红色二元离子缔合物,产生一个较强的正吸收峰和一个较强的负吸收峰,最大正吸收峰位于576 nm,最大负吸收峰位于522 nm,在此二波长处,两单波长法的线性范围均为0.02～3.7 mg·L~(-1),表观摩尔吸光系数(κ)分别为4.37×10~4 L·mol~(-1)·cm~(-1)和1.08×10~4 L·mol~(-1)·cm~(-1)。当用双波长法测定时,线性范围为0.02～3.7 mg·L~(-1),表观摩尔吸光系数(κ)为5.45×10~4 L·mol~(-1)·cm~(-1)。将576 nm处的单波长法用于药物中吡哌酸含量的测定,回收率和相对标准偏差(n=5)分别为97.5%～102%和2.5%～2.8%。     

双体系双波长荧光光度法及其在药物分析中的应用

提出一种新型“双体系双波长荧光光度法”（ＤＳＤＷＦ），并用于性质相近药物苯酚及间苯二酚的同时测定，测定下限为０．０５μｇ／ｍＬ，苯酚与间苯二酚的浓度允许比为１：１０－１０：１。用于模拟复方雷琐辛涂剂的测定，结果满意。     

石墨炉双原子分子吸收光谱法测定微量氯

对用AICI双原予分子吸收光谱法测定氯进行研完，使用涂钼石墨管可使灵敏度有较大的提高。采用铅空心阴极灯作光源，峰值吸收测量方式，基体改进剂并先于氯进样，两次干燥等诸项技术联合运用，可使AICI-MAS法具有实用意义，方法的灵敏度为2.2×10-l0g/1%A，精密度为2.3％，在测试浓度范围内，有两个线性范围0～1.2mg·L-1和1.2～3，6mg·L-1。     

多元校正滴定法测定酒石酸美托洛尔

以氢离子选择性电极为工作电极,盐酸或氢氧化钠为滴定剂,用多元校正滴定法对酒石酸美托洛尔片的含量进行了测定。探讨了盐酸或氢氧化钠测定酒石酸美托洛尔的可行性,比较了过滤和不过滤两种方法配制试液的测定结果。本法测定结果与中国药典(1995)中非水滴定法的对照偏差在1%之内;采用过滤和不过滤两种方法配制的试液测定结果之间的偏差在0.2%之内。     

Kinetic Spectrophotometric Determination of Metoprolol Tartrate in Commercial Dosage Forms

A kinetic spectrophotometric method has been described for the determination of metoprolol tartrate in commercial dosage forms. The procedure is based on the reaction of the drug with 1‐chloro‐2, 4‐dinitrobenzene (CDNB) in dimethylsulfoxide (DMSO) at 100 ± 1 °C. The reaction is investigated by measuring the change in absorbance with time at 420 nm. Fixed‐time (ΔA) and equilibrium methods are chosen for obtaining the calibration curves. Both calibration curves were found to be linear over the concentration range of 5‐60 μg mL^?1. The regression analysis of calibration data resulted in the linear regression equations of ΔA = ?1.608 × 10^?4 + 3.96 × 10^?3 C and A = 7.31 × 10^?4 + 1.90 × 10^?2 C for fixed time (ΔA) and equilibrium methods, respectively. The limit of detection (LOD) for fixed time and equilibrium methods are 1.16 and 0.415 μg mL^?1, respectively. The method has been successfully applied to the quantitation of metoprolol tartrate in commercial dosage forms. Statistical comparison of the results shows that there is no significant difference between the proposed methods and El‐Ries's spectrophotometric method.     

Determination of Metoprolol Tartrate as Cu(II)-Dithiocarbamate Complex

Abstract

An HPLC method has been developed for the determination of the beta adrenergic blocking drug metoprolol tartrate. The method is based on the formation of a Cu (II) - dithiocarbamate complex by precolumn derivatization of secondary amino group of metoprolol with CS₂ and CuCl₂ in the presence of ammonia. The complex is extracted into chloroform and injected into the chromatograph. Chromatographic separation was performed by a RP (μ Bondapak C₁₈) column with methanol - pH 5.8 phosphate buffer (80 : 20) as the isocratic mobile phase. A variable wavelength absorbance detector (λ = 275 nm) was used. A linear relationship was obtained between peak areas and metoprolol tartrate concentrations over the range of 35 - 180 nmol ml^?1. The method was applied to the analysis of metoprolol tartrate tablets and the results were statistically compared with those obtained by official method using t - and F - tests.     

聚乙烯吡啶化学修饰电极预富集-石墨炉原子吸收法测定酒石酸锑钾的研究

本文研究了聚乙烯吡啶(PVP)化学修饰电极预富集——石墨炉原子吸收法测定酒石酸锑钾的方法。结果表明,在 pH 为3.5的 HCl 介质中,酒石酸锑钾浓度在5.4×10~(-8)～2.2×10~(-6)g/ml 范围内,与吸光度值呈良好的线性关系。对1.1×10~(-6)g/ml 的酒石酸锑钾溶液平行测定9次,相对标准偏差为4.9%,最低检测限为1.6×10~(-8)g/ml。17种异离子及有机物不干扰测定,回收率在97～103%之间,结果令人满意。     

间接原子吸收分光光度法测定锆

研究了空气－乙炔火焰原子吸收光谱法间接测定微量锆的方法,在弱酸性溶液中钢与Ｎ－亚硝基苯胲（铜铁试剂）形成１：２络合物可被氯仿定量萃取,Ｚ ｒ（Ⅳ）定量置换Ｎ－亚硝基苯胲钢中的铜,原子吸收光谱法测铜间接测锆,特征浓度为 ０．０７ × １０－６ ｇ／ｍＬ／１％,线性范围为 ０～５ｍｇ／Ｌ,方法简便、快速、灵敏度高,选择性好,用于瓷釉和α－βＡｌ２Ｏ３中氧化锆的测定,结果满意。     

原子吸收法间接测定微量锆

间接原子吸收光谱法的研究受到人们的普遍重视,主要有利用杂多酸的“化学放大”效应间接测定磷、砷、锗;沉淀反应间接测定氯离子、硫酸根,化学干扰效应间接测定钛、铝及络合效应间接测定钒、硼、硝酸根等,但在间接测锆方面未见报道,本文用Mg-8-羟基喹啉(MgL_2)沉淀锆置换出定量的镁,通过测镁间接测锆,建立了空气-乙炔火焰原子吸收光谱法间接测定锆的新体系,方法的特征浓度为0.018mg/L/1%,较氧化亚氮乙炔火焰(10mg/L/1%)提高500倍,该方法灵敏、快速、体系稳定,经萃取分离除去干扰元素,用于实际样品中氧化锆的测定,结果满意.2 实验部分     

原子吸收光谱法测定痕量铕

探讨了痕量铕的富集、解吸条件及测定时的干扰情况.实验表明适量Fe²⁺的存在才能满足分析要求.利用浸钽液热解镀层石墨管和光温控制技术以保证方法的灵敏度和重现性.方法操作简便、结果准确,适合大批岩石、矿物中Eu₂O₃大于1×10^-5%的测定.     

Indirect Determination of Cyanide by Atomic Absorption Spectrometry

Abstract

Two methods for determination of cyanide by atomic absorption spectrometry (AAS) are developed. Both methods are based on the formation of an ion association compound between a metal complex, (Ag(CN)₂ ^? or Cu(CN)₃ ^2-), and a quaternary ammonium ion (benzyldimethylhexadecylammonium ion). The ion association compound is extracted into isomethylbutylketone (IBMK) and the metal is determined by AAS directly in extract. The method based on the formation of silver cyanide complex provides a reproducibility of 2.5%, a recovery of 99% and a detection limit of 1.7 μg/L while the method based on the formation of copper complex gives a reproducibility of 6%, a recovery of 93% and a detection limit of 0.6 μg/L. Several foreign ions were studied: the method based on the formation of Ag(CN)₂ ^? presents minor interferences.     

硫化物的冷分子吸收光谱法测定

本文研究了用冷分子吸收光谱法测定硫化物的方法。并用断续进样法测定了湖水、河水及大气中Ｓ＾２－的含量，结果令人满意。