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 共查询到19条相似文献,搜索用时 66 毫秒
1.
姚成  王镇浦 《分析化学》1996,24(12):1452-1455
非离子表面活性剂OP存在下,钨(Ⅵ)与新显色剂4-(6-溴-2-苯并噻唑偶氮)邻苯二酚在PH4.0-5.2介质中反应形成稳定的、带负电荷的、紫红色三元胶束络合物。  相似文献   

2.
1 引 言 DBC-偶氮氯膦全称为:2-(4-氯-2-膦酸基苯偶氮)-7-(2,6-二溴-4-氯苯偶氮)-1,8-二羟基3,6-萘H磺酸,简写为DBC-CPA。它已用于稀土、钡、锶、钙和钐的测定。作者在研究了该试剂与铁显色反应的基础上,又研究了与铋的显色反应,发现在1.2moL/L HClO4的介质中,于少量乙醇存在下,试剂与铋生成2:1的络合物,络合物稳定性好,灵敏度高,其表观摩尔吸光系数 1.08× 105 L·mol-1·cm-1,常见离子:银、镁、镉、钴、镍、铜、锰、铝、锌、铁、铬、硅等允许共…  相似文献   

3.
姚成  王镇浦 《分析化学》1996,24(12):1425-1428
pH4.5时,Mo(Ⅵ)与显色剂4-(2-苯并噻唑偶氮)邻苯二酚反应形成带负电荷的稳定紫红色1:2二元络合物。40%丙酮水溶液中λmax为560nm,表观ε560为6.33×10^4L.mol^-1.cm^-1。  相似文献   

4.
盐酸羟胺的间接分光光度法测定   总被引:3,自引:1,他引:2  
拟定了在铁(Ⅲ)—2-[2-(6-甲基苯并噻唑)偶氮]-5-二乙氨基苯甲酸(6MeBTAEB)络合物和十二烷基硫酸钠存在下盐酸羟胺的间接分光光度测定方法,回收试验表明该法准确可靠,方便快捷。同时测定了盐酸羟胺与Fe(Ⅲ)-6_Me_BTAEB络合物的反应比。  相似文献   

5.
郭忠先 《分析化学》1996,24(4):459-462
研究了在乳化剂OP存在下,2-羟基-3-羧基-5-磺酸基苯重氮氨基偶氮苯(HCSDAA)-汞(Ⅱ)显色体系流动注射分光光度法。用PH10.0-10.5的Na2B4O7-NaOH缓冲溶液作载流,汞(Ⅱ)与HCSDAA和乳化剂OP的混合试剂反应形成红色络合物。用于测定汞时,方法的线性范围是0.05-1.0mg/L,检测限为0.016mg/L,进样频率为100样/h。直接应用于头发、自来水和废水中微量汞  相似文献   

6.
本文研究了在Cd(Ⅱ)和TritonX-100存在下,meso-四(4-乙酰氧基苯)卟啉[T(4-AOP)P]与钌(Ⅲ)的显色反应。结果表明,在pH9.7~10.3介质中,Ru(Ⅲ)与T(4-AOP)P形成了灵敏度很高的稳定络合物,其表观摩尔吸光系数为7.04×105L·mol-1·cm-1。钌浓度在0~1.2μg/10mL范围内服从比尔定律。络合物的摩尔比为Ru(Ⅲ)∶T(4-AOP)P=1∶1。在掩蔽剂存在下,方法有一定的选择性,应用于合成试样中钌的测定,结果满意。  相似文献   

7.
张光  张林林 《分析化学》1997,25(1):79-81
报道以5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯(5-NO2-PADAT_作为测定钌的分光光度法。在40%乙醇存在下PH4.0-6.5乙酸-乙酸钠缓冲溶液中5-NO2-PADAT与Ru(Ⅱ)形成稳定的红色络合物。该络合物的无机酸作用下,可转变为另一型人有较高吸收特性的络合物,适宜酸度范围分别为0.12-2.0mol/LHCl,0.12-1.2mol/LHClO4,0.12-1.0mol/L  相似文献   

8.
锗(Ⅳ)-邻苯二酚紫-钒(Ⅳ)体系的极谱吸附催化波研究   总被引:5,自引:0,他引:5  
在0.1mol/LH2SO4溶液中,Ge(Ⅳ)-邻苯二酚紫(PV)-V(Ⅳ)体系产生一灵敏的吸附催化波,峰电位在-0.55V(vs.SCE)处.锗浓度在2.2×10-10~2.8×10-6mol/L范围内与峰电流呈线性关系.检出限为1.1×10-10mol/L.研究了极谱波的性质.本法用于土壤中痕量锗的测定,结果满意.  相似文献   

9.
镉(Ⅱ)-2-(2-苯并噻唑偶氮)-5-二甲氨基苯甲酸配合物的吸附伏安法研究及应用徐素君,施清照,张培敏,吴念慈(杭州大学化学系310028)关键词:2-(2-苯并噻唑偶氮)-5-二甲氨基苯甲酸(BTAMB),镉,吸附伏安法杂环偶氮试剂的极谱性质及其...  相似文献   

10.
研究了新显色试剂6-硝基-苯并噻唑重氮氨基偶氮苯与Hg(Ⅱ)的显色反应。在乳化剂OP存在下,于pH10.0的缓冲溶液中,Hg(Ⅱ)与显色剂形成1:2的稳定红色络合物。络合物的λmax=515nm,其表观摩尔吸光系数为1.53×10^5L·mol^-1·cm^-1,Hg(Ⅱ)含量在0 ̄5μg/10mL范围符合比尔定律,样品分析结果令人满意。  相似文献   

11.
8-喹啉偶氮显色剂QADCB的合成及其分析性能的研究   总被引:4,自引:0,他引:4  
报道了8-喹啉偶氮显色剂2-(8-喹啉偶氮)-5-二羧甲氨基苯甲酸(QADCB)的合成、提纯与鉴定,研究了其与Co(Ⅱ)、Ni(Ⅱ)、Fe(Ⅲ)的显色反应,对QADCB与Co(Ⅱ)的显色反应作了研究。在pH5.9的缓冲体系中,试剂与Co(Ⅱ)形成棕红色配合物,其最大吸收波长位于650nm,表观摩尔吸光系数为4.2×104L.mol-1.cm-1,钴量在0~20μg/25mL范围内符合比耳定律。方法简便、快速,选择性较好,已用于纯铜、维生素B12中微量钴的测定,结果满意。  相似文献   

12.
研究了1-偶氮苯-3-(6-甲氧基-2-苯并噻唑)-三氮烯(AMBT)与锌的显色反应,在pH11.0的Na2CO3-NaHCO3缓冲溶液中,TritonX-100存在下,AMBT与Zn(Ⅱ)反应生成2∶1稳定络合物,其最大吸收波长为535nm,表观摩尔吸光系数为8.37×104L.mol-1.cm-1。锌质量浓度在0~0.40μg/mL内符合比尔定律,方法用于测定粉煤灰中微量锌,结果与极谱法相符,RSD<3%。  相似文献   

13.
研究了3 -(6-溴苯并噻唑-2-偶氮)- 2,6-二羟基苯甲酸(简称BTAB)与铁的配合反应.用摩尔比法、等摩尔连续变化法、平衡移动法和双峰双波长法四种方法详细研究并测定了3 -(6-溴苯并噻唑 -2-偶氮)- 2,6-二羟基苯甲酸与铁显色形成配合物的配合比和稳定常数,建立了光度法测定铁的新方法.结果表明,在溴代十六...  相似文献   

14.
The visible absorption spectra of 4-(2-benzothiazolylazo)resorcinol (BTAR) and 4-(2-benzothiazolylazo)salicylic acid (BTAS) have been recorded in water-organic solvent mixtures in the pH range 0.5–12.0. The organic solvents used are methanol, ethanol,n-propanol, iso-propanol, acetone, dioxane and dimethyl formamide. The spectral changes have been explained in terms of shifts in equilibria among different molecular and ionic species of BTAR and BTAS existing in solution. The pK a values corresponding to the different ionization steps have been determined at 25°C and I=0.1M (KNO3) by graphic analysis of the absorbance-pH curves. The results obtained are discussed in terms of the molecular structure of the reagents and the nature of the organic co-solvent used.  相似文献   

15.
在含有 3.6×10-3mol/L 的 VOSO4、6.0×10-5mol/L 的 3,4-二羟基苯甲酸(DHBA)、 0.1mol/L 的甲酸盐缓冲溶液(pH3.3)体系中,Sn(Ⅳ)-DHBA 络合物产生一灵敏的吸附平行催化波,峰电位在 -0.52 V(vs.SCE).二次导数波高与锡浓度在 3.4×10-10~5.1×10-7mol/L 范围内呈良好线性关系.检出限达浓度 2×10-10mol/L .研究了催化波的性质和电极反应机理.方法已应用于罐头食品中微量锡的测定.  相似文献   

16.
An extraction-spectrophotometric method for the determination of trace amounts of iron based on its extraction into chloroform with 2-(2-benzothiazolylazo)-4,6-dimethylphenol (BTADMP) from a pH 6.5 medium has been developed. The extracted 12 FeBTADMP complex species allow the determination of 4–30gmg of iron (=3.92×1041·mol–1·cm–1 at 790 nm). The method is highly selective and has been applied to the determination of iron in polymineral-polyvitamin pharmaceutical products.  相似文献   

17.
Detailed equilibrium and kinetic studies on axial water ligand substitution reactions of the "lantern-type" platinum(III) binuclear complex, [Pt(2)(mu-HPO(4))(4)(H(2)O)(2)](2)(-), with halide and pseudo-halide ions (X(-) = Cl(-), Br(-), and SCN(-)) were carried out in acidic aqueous solution at 25 degrees C with I = 1.0 M. The diaqua Pt(III) dimer complex is in acid dissociation equilibrium in aqueous solution with -log K(h1) = 2.69 +/- 0.04. The consecutive formation constants of the aquahalo complex () and the dihalo complex () were determined spectrophotometrically to be log = 2.36 +/- 0.01 and log = 1.47 +/- 0.01 for the reaction with Cl(-) and log = 2.90 +/- 0.04 and log = 2.28 +/- 0.01 for the reaction with Br(-), respectively. In the kinetic measurements carried out under the pseudo-first-order conditions with a large excess concentration of halide ion compared to that of Pt(III) dimer (C(X)()- > C(Pt)), all of the reactions proceeded via a one-step first-order reaction, which is a contrast to the consecutive two-step reaction for the amidato-bridged platinum(III) binuclear complexes. The conditional first-order rate constant (k(obs)) depended on C(X)()- as well as the acidity of the solution. From kinetic analyses, the rate-limiting step was determined to be the first substitution process that forms the monohalo species, which is in rapid equilibrium with the dihalo complex. The reaction with 4-penten-1-ol was also kinetically investigated to examine the reactivity of the lantern complex with olefin compounds.  相似文献   

18.
Amin AS  Ibrahim MS 《Annali di chimica》2001,91(1-2):103-110
Three new heterocyclic azo compounds, 5(2-benzothiazolylazo)2,2 biphenyldiol (I), 5-(2-benzothiazolylazo)-8-hydroxyquinolene (II) and 4-(2-benzothiazo-lylazo)3-hydroxy-2-naphthoic acid (III) were synthesized. The formation constant of the reagents in 30% (v/v) ethanol and reactions with various metal ions were studied. These reagents (I-III) reacts with nickel ion to form (2:1) colored complex with an absorption band at 604, 635 and 643 nm. The apparent stability constants and the optimum conditions for complete color development were investigated. Beer's law is obeyed over the concentration ranges of 0.05-3.50, 0.05-4.00 and 0.05-3.10 micrograms ml-1. For more accurate analyses, Ringbom optimum concentration ranges were found to be 0.20-3.25, 0.20-3.80 and 0.20-2.90 micrograms ml-1 using reagents I, II and III, respectively. The apparent molar absorptivity and Sandell sensitivity were also calculated. The interference of various foreign ions on the determination of nickel was investigated. The proposed method has been successfully applied to the determination of nickel substrates in various biological samples.  相似文献   

19.
An extraction-spectrophotometric method is described for the determination of traces of iron(II) with 2-[2-(3,5-dibromopyridyl)azo]-5-diethyl-aminobenzoic acid. The reagent forms a stable and blue 12 iron/reagent complex that can be extracted into chloroform. The apparent molar absorptivity of the iron(II) complex is 1.09 × 105 1 mol–1 cm–1 at 624 nm in chloroform. The reagent is relatively selective; interferences from cobalt, copper, nickel and vanadium can be removed by using dimethylglyoxime and EDTA. The method is applied to the determination of iron (II) in sea water and aluminium alloys with good precision and accuracy.  相似文献   

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