三唑螯合树脂分离富集催化光度法测定痕量金

研究了三唑螯合树脂 (AMTR)在盐酸介质中分离富集金 ,吸附的容量大 ,选择性高 ,无污染。同时研究了分离后在盐酸介质中 ,在抗坏血酸 (VC)存在下痕量金 催化溴酸钾氧化偶氮氯膦S褪色的指示反应及其动力学条件 ,据此建立测定痕量金 的新方法。方法的检出限为 4.16× 10 - 7g L ,测定范围为 0～ 70mg L ,用于样品的测定获得满意结果。     

Determination of Low Contents of Fenpiverine Bromide by Extraction Spectrophotometry

An ion-pair extraction spectrophotometry method was developed for the determination of fenpiverine bromide in tablets. To determine this substance it was necessary to find experimental conditions that would allow eliminating the influence of other components of the tablets. Attention was paid to the fact that a suitable pH of water phase was necessary to achieve high selectivity.Received December 11, 2002; accepted April 24, 2003 Published online July 28, 2003     

Spectrophotometric and titrimetric determination of gallium in minerals and ores using semimethylthymol blue

The composition, overall stability constant and molar absorptivity of the chelate of gallium(III) ion with semimethylthymol blue, SMTB, were determined spectrophotometrically in acetate buffer (pH 4.5–5). A violet Ga(SMTB) chelate was formed with logarithmic overall stability constant of 18.0±0.1 (I=0.1) and molar absorptivity of 4.25×10⁴l mol^–1cm^–1 (_max 580 nm). SMTB is proposed as a new reagent for the spectrophotometric determination of micro-molar amounts of gallium(III). The colour development depends on time, temperature, pH and buffer species. The interference of different cations, anions and organic acids on gallium(III) determination was also investigated. Beer's law was obeyed for 3.5–31.3 gGa(III)/25ml (0.14–1.25 g ml^–1). SMTB was used for the spectrophotometric determination of gallium in different grade minerals and ores and the results were of acceptable error and relative standard deviation. Comparison between the two suggested methods and atomic absorption spectrometry for Ga(III) determination was carried out.     

Spectrophotometric assay of cephalosporins in pharmaceutical products,using chromotrope 2B and chromotrope 2R

A simple, rapid and sensitive Spectrophotometric method is proposed for the determination of cephadroxil (I), cephalexin (II) and cephradine (III). The method is based on ion-pair complex formation between these derivatives and Chromotrope 2B (C2B) or Chromotrope 2R (C2R), to give a highly coloured radical anion. The coloured products are quantified spectrophotometrically at 542 and 564 nm for C2B and C2R, respectively. The optimization of the experimental conditions is described. The method has been used for the determination of 0.4–15, 0.4–14 and 0.4–18 g/ml of drugs I, II and III, respectively. The accuracy of the method is indicated by the excellent recovery (100.0±1.7%) and the precision is supported by the low relative standard deviations 1.5%. The sensitivity of the method is discussed and the results are compared with the official method. The interference from common degradation products and excipients was also studied. The proposed method was applied successfully to the determination of the different cephalosporins in dosage forms, with good precision and accuracy. The results were compared with those given by the official B.P. 1993 method.     

铀-2-(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚-Triton X-100析相体系的研究及应用

本文研究了铀-2-(3,5-二溴-2-吡啶偶氨)-5-二乙氨基苯酚(3,5-diBr-PADAP)-Triton X-100析相光度体系,建立了矿石中微量铀的测定方法,在pH 7.5三乙醇胺-盐酸介质中,将胶束溶液在 95±1℃加热 1h.络合物即被Triton X-100相完全富集.络合物最大吸收峰位于565nm.摩尔吸光系数为1.02×10～5L·mol～(-1)·cm～(-1),铀含量在0～12μg/5mL服从比耳定律.采用TBP萃淋树脂分离干扰离子,测定矿石中微量铀,结果满意.     

二乙基二硫代氨甲酸银体系流动注射法测定砷

本文设计了一种ＡｇＤＤＣ流动注射－分光光度法测定砷的系统。该系统采用自制的氢化物发生及吸装置，将液体流路和载气流路结合在一起。     

二溴羧基偶氮胂催化光度法测定痕量钴

研究了在硼砂 -氢氧化钠缓冲介质中 ,痕量钴 (Ⅱ )与三乙醇胺协同催化H2 O2 氧化二溴羧基偶氮胂褪色的最佳条件。λmax=5 70nm ,表观摩尔吸光系数为 3 7× 1 0 4 L·mol- 1·cm- 1,线性范围 1 5～ 4 0 μg/2 5mL。方法已用于茶叶中痕量钴的测定。     

双波长分光光度法同时测定贵金属钯和锇

本文提出了在对羟基苯基荧光酮和溴化十六烷基三甲烷基甲胺存在下，双波长分光光度法同时测定微量和锇的新方法，在ｐＨ＝７．６～８．０的磷酸盐介质中，钯和锇的对羟基苯基荧光酮－ＣＴＭＡＢ配合物吸收光谱相互重叠，选择测定钯配合物的波长对为５８０．５ｎｍ与５３０．５ｎｍ，测定锇配合物的波长对为５５３．５ｎｍ与６０４．５ｎｍ，钯含量在０～７．０μｇ／１０ｍＬ范围内，锇含量在０～９．０μｇ／ｍＬ范围内，与ΔＡ值呈     

2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺与铂(Ⅳ)显色反应的研究

研究了２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺（３，５－ｄｉＣｌ－ＰＡＤＭＡ）与铂（Ⅳ）的显色反应及铂配合物的质子化行为。结果表明，在０．０４～０．４８ｍｏｌ／Ｌ的Ｈ２ＳＯ４溶液中，于加热的条件下，试剂可与铂（Ⅳ）形成稳定的１∶２绿蓝色ＰｔＬ２Ｈ２＋２配合物，其最大吸收波长位于６３４ｎｍ，表观摩尔吸光系数为９．７３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，桑德尔灵敏度为０．００２μｇ·ｃｍ－２。铂配合物的三级质子化常数分别为：ｌｇＫａ１＝３．９１，ｌｇＫａ２＝－２．２１，ｌｇＫａ３＝－３．３７。较大量的常见金属离子及除钯、钌外的其它贵金属离子不干扰测定。利用Ｐｔ，Ｐｄ与试剂反应所需的温度差异，可以用差减法消除微量Ｐｄ的干扰．铂（Ⅳ）浓度在每１０ｍＬ０～７．５μｇ范围内符合比尔定律。所拟方法用于二次合金管理样－８８及催化剂中微量铂的测定，结果满意。     

Determination of pefloxacin in serum and pharmaceutical forms by derivative spectrophotometry

A method for the direct determination of pefloxacin in serum and pharmaceutical forms (tablets and ampoules) has been developed, based on the use of second-order derivative ultraviolet spectra. Spectrophotometric assay of pefloxacin in tablets and ampoules was carried out in 0.1 mol/L NaOH, while in serum it was performed in 0.1 mol/L NaOH with the addition of sodium dodecylsulfate, in 337–347 nm wavelength range. Linear calibration curves were obtained in the concentration ranges 2–30g/mL pefloxacin for tablets and ampoules and 0.12–5 g/ mL for serum samples. Relative error of determination, as criterion for accuracy, was less than 1%, while the precision was better than 4 ng/ml. The minimum detectable concentration of pefloxacin in serum was 15 ng/mL.