尿砷的测定方法

笔者对近年来国内外尿液中砷元素的测定方法进行了综述。详细描述了不同仪器在测定尿砷时的方法和得到的结果,并介绍了各个方法的特点,便于不同条件实验室检验人员进行方法的选择。     

磺基水杨酸作萃取剂铜、镧、铈的萃取分离研究

目的:利用磺基水杨酸作萃取剂,在吐温80-硫酸铵固-液体系中,萃取分离Cu(Ⅱ)、La(Ⅲ)、Ce(Ⅳ)金属离子。方法:研究了萃取相(固相)中磺基水杨酸及金属离子络合物吸收光谱;不同酸度、不同盐用量、不同萃取剂用量、不同类型表面活性剂对Cu(Ⅱ)、La(Ⅲ)、Ce(Ⅳ)离子萃取率的影响。结果:与磺基水杨酸光谱比较,Cu(Ⅱ)、Ce(Ⅳ)离子吸光度增大,最大吸收波长红移;La(Ⅲ)离子几乎未变。在pH2.0的酸度下,实现了Cu(Ⅱ)与La(Ⅲ)之间的萃取分离。结论:方法具有简便、快速、易于操作的优点,用于金属离子的萃取分离效果较好。     

血清硒测定方法的研究:氢化物原子吸收法

使用原子吸收分光光度计及氢化物发生器测定血清硒。回收率94.9～～106%,相对标准偏差(R·S·D)2.5%,检出限为0.46μg/L。     

罗红霉素胶囊及片剂的溶出度考察

目的考察不同厂家及同一厂家不同批号罗红霉素胶囊或片剂的溶出度。方法采用转篮法和分光光度法测定模拟胃液中罗红霉素体外溶出度,绘制累积溶出曲线图,以溶出百分率的对数对时间进行线性直线拟合,求得溶出参数T50、T75。并进行统计学分析。结果经t检验,不同厂家中除了B与D、E与F、E与G的T50与T75平均值差异不显著(P>0.05),其他都有显著差异(P<0.01);而同一厂家不同批号的均值差异不显著(P>0.05)。结论不同厂家罗红霉素制剂体外溶出度存在显著差异。     

紫外分光光度法测定维生素D3注射液的含量

目的测定维生素D3注射液的含量。方法:采用紫外分光光度计在265±1nm波长处测定维生素D3溶液的吸收度。结果:维生素D3的浓度与吸收度呈良好的线性关系,r=0.9996,样品的平均吸收率为99.6%。结论:本办法操作简单,实用性强,结果准确可靠。     

Sensitive spectrophotometric determination of amlodipine and felodipine using iron(III) and ferricyanide

A simple, accurate, sensitive and economical procedure for the estimation of amlodipine besylate and felodipine, both in pure form and in formulations has been developed. The method is based on the reduction of iron(III) by the studied drugs in acid medium and subsequent interaction of iron(II) with ferricyanide to form Prussian blue. The product exhibits absorption maximum at 760 nm in both cases. Beer's law is obeyed in the concentration ranges 5.0-15.0 and 1.5-5.0 microg/ml, for amlodipine and felodipine, respectively. The molar absorptivities are 1.76 x 10(4) and 4.24 x 10(4) l/mol cm. The corresponding Sandell sensitivities are 23.18 and 9.06 ng/cm(2). The limits of detection as well as quantification are reported. Seven replicate analyses of solutions containing three different concentrations of each drug were carried out and the percent error and the RSD values have been reported. The proposed method was applied to the determination of these drugs in pharmaceutical formulations and the results demonstrate that the method is equally accurate and precise as the official methods as found from the t- and F-values. The reliability of the method was established by recovery studies using standard-addition technique.     

紫外分光光度法测定吉非罗齐含量

目的建立用紫外分光光度法到定吉非罗齐的含量；方法以乙醇为溶剂，采用分光光度法，在276nm到定吉非罗齐含量；结果 吉非罗齐在0—219．2μg／m1范围内，其吸收度呈良好的线性，R＝0．9999，平均回收率100．1％，RSD为0．36％。结论 本法简便快速，结果与药典法基本一致。     

催化动力学分析法测定空气中的微量锰

报道了催化动力学分析法测定空气中微量锰的方法。空气样本经微孔滤膜采集后,用1.0mol. L~(-1)HCl在沸水浴中浸取2h,然后利用锰(Ⅱ)对KIO_4氧化孔雀绿的催化作用对锰比色测定。本法检测下限为0.1ng/ml,线性范围为0～80ng/25ml,变异系数为1.1～12.9%,加标回收率为91.3～106.5%。常见共存成分对测定无干扰。     

化妆品中新银盐法测定砷的问题研究

目的：通过对聚乙烯醇-硝酸银-乙醇分光光度法测定化妆品中砷的存在问题的实验研究分析，完善国家卫生规范检验方法。方法：消化处理后样品中的五价砷在碘化钾和氯化亚锡的作用下还原为三价砷经聚乙烯醇-硝酸银-乙醇溶液吸收形成黄色胶态银，比色测定。对不同室温下的标准系列的显色数据进行了方差分析。结果：不同室温下混合吸收液对同一含量的砷氢的吸收显色存在的差异有统计学意义（P〈0．01）。结论：作为国家的卫生规范检验方法，聚乙烯醇＋硝酸银＋乙醇混合吸收分光光度法存在缺陷，为此建议增加相应的实验必要条件。     

Application of ninhydrin to spectrophotometric determination of famotidine in drug formulations

A simple and fast spectrophotometric procedure has been developed for the determination of famotidine. The method is based on the interaction of ninhydrin with primary amines present in the famotidine. This reaction produces a blue coloured product which absorbed maximally at 590 nm. The effects of variables such as reagent concentration and reaction time were investigated to optimize the procedure. Beer's law was obeyed in the concentration range of 5-30 microg ml(-1) with molar absorptivity of 6.99 x 10(3) l M(-1) cm(-1). The results were validated statistically. The proposed method has been applied to the determination of famotidine in tablets with satisfactory results.