汞-邻菲啰啉-刚果红缔合体系光度法测定痕量汞

在含有汞(Ⅱ)试液中,先后加入乙酸-乙酸钠缓冲溶液(pH 5.7)、1.0×10-3mol.L-1邻菲啰啉溶液0.8 mL、4.0×10-4mol.L-1刚果红溶液1.2 mL及10 g.L-1阿拉伯树胶(GA)溶液0.8 mL使反应生成汞与邻菲啰啉和刚果红的络合物。在此缔合体系中,GA对显色反应兼有增敏和增稳作用。汞(Ⅱ)质量浓度在1.0 mg.L-1范围内与其吸光度呈线性关系。反应体系的吸收峰位于540 nm波长处,在此波长条件下测定其表观摩尔吸光系数为8.49×104L.mol-1.cm-1。此方法已应用于测定河水中汞量,求得相对标准偏差(n=5)小于2.0%,平均回收率为100.4%。     

邻菲啰啉-Fe(Ⅱ)分光光度法测定头孢唑啉钠

建立了用邻菲啰啉-Fe(Ⅱ)分光光度法测定头孢唑啉钠的方法 .头孢唑啉钠在0.10mol·L-1 NaOH溶液中,100℃水浴加热降解为含巯基的化合物.巯基化合物把Fe3+还原为Fe2+.加入邻菲啰啉显色,通过测定生成的橘红色配位化合物的吸光度间接测定头孢唑啉钠的含量.头孢唑啉钠浓度在0.02~40mg·L-1范围内呈现良好线性关系,线性回归方程A=0.043c(mg·L-1)-0.001,相关系数R=0.998 8,表观摩尔吸光系数ε=2.05×104 L·(mol·cm)-1,相对标准偏差RSD=1.27%,检测限(3σ/k)0.065mg·L-1.在此基础上,测定了市售头孢唑啉钠粉针剂的含量,回收率在99.17%~101.2%之间,结果令人满意.     

邻菲啰啉-Fe(Ⅱ)体系光度法间接测定硫普罗宁

在酸性介质中硫普罗宁可将Fe(Ⅲ)还原为Fe(Ⅱ),邻菲啰啉能与生成的Fe(Ⅱ)显色,最大吸收波长为508 nm。基于此,通过测定Fe(Ⅱ)的量间接测定了硫普罗宁的含量。硫普罗宁在0.08~20μg/mL范围内与ΔA呈良好的线性关系,线性回归方程为ΔA=0.01283+0.06516c(μg/mL),线性相关系数为0.9998,检出限为0.042μg/mL。本方法可用于实际药品中硫普罗宁含量的测定。     

邻菲啰啉－曙红体系共沉淀纸上分光光度法测铁

采用邻菲 啉试剂作为络合剂，与铁（Ⅱ）形成络阳离子后，用曙红阴离子缔合沉淀之，再加入酚酞共沉淀剂使其缔合沉淀完全。将络离子缔合物吸滤在滤纸，后者直接置于７２１型分光光度计中，用吸光度差值法定量。操作简单快速，选择性好，灵敏度高；以取样体积１０ｍＬ计，最小检出浓度为１．５×１０￣（－９）ｇ／ｍＬ。     

KIO4-偶氮氯膦mA-邻菲啰啉体系催化光度法测定痕量锰

1引言 现代医学研究表明,微量元素作为机体的营养物质与人体的正常代谢有密切关系.     

邻菲啰啉-Fe(Ⅱ)体系光度法间接测定头孢噻肟钠

基于头孢噻肟钠在0.3 mol/L NaOH溶液中沸水浴降解产物具有还原性,在酸性介质中可将Fe(Ⅲ)还原为Fe(Ⅱ),邻菲罗啉能与所生成的Fe(Ⅱ)显色生成红色络合物,最大吸收波长λ=508 nm;表观摩尔吸光系数ε=1.1×104 L·mol-1·cm-1;头孢噻肟钠在0.4～80 μg/mL范围内呈良好的线性关系;线性回归方程为A=-0.00204 0.01989ρ(μg/mL);线性相关系数r=0.9998;检出限为0.18 μg/mL;RSD为1.2%(5.0 μg/mL,n=11);平均回收率为99%.初步探讨了反应机理,并优化了对头孢噻肟钠的测定条件.     

铁-邻菲啰啉体系中的化学振荡及铁(Ⅱ)测定的研究

实验发现,Fe-邻菲啰啉体系中存在化学振荡。本文对振荡的规律进行了初步的探讨并提出了有效的振荡抑制剂。添加抑制剂后,邻菲啰啉分光光度法可以在Fe(Ⅱ)存在时,准确测定Fe(Ⅰ)。     

1,10-邻菲(口罗)啉荧光光度法测定微量元素硒

研究了痕量元素硒的荧光强度测试新方法,进行了最佳条件实验.该法有良好的线性关系(r=0.9991),检测限是1.0×10-9mol·L-1,RSD(n=6)为0.47%,回收率在92.6%～106.9%之间.     

流动注射邻菲啰啉化学发光体系测定羟自由基

利用Vitc-CuSO4-H2O2产生的羟自由基,建立流动注射邻菲口罗啉化学发光体系测定羟自由基的产生及物质对羟自由基的清除能力。体系中各种物质浓度的最佳组合是:邻菲口罗啉1.0×10-3mol/L(pH 8.2硼砂-硼酸缓冲液配制、内含CTMAB浓度为5.0×10-3mol/L)、Cu2+1.5×10-3mol/L、H2O2体积分数0.6%、抗坏血酸1.5×10-3mol/L。硫脲清除羟自由基的量效关系Y=25.0009ln(x)+65.3120,r=0.9988,IC50=0.542 mmol/L。龙井茶水提液对羟自由基具有较强的清除作用。     

聚(苯乙烯-丙烯酸)载体铁邻菲啰啉(5-硝基邻菲啰啉)配合物的合成及其对丁二烯聚合的催化活性

合成了不同邻菲啰啉(phen)含量的聚(苯乙烯-丙烯酸)载体铁邻菲啰啉配合物(SAAC·Fe·phen)和不同5-硝基邻菲啰啉(Nphen)含量的聚(苯乙烯-丙烯酸)载体铁5-硝基邻菲啰啉配合物(SAAC·Fe·Nphen)。元素分析和红外结果证明SAAC·Fe·phen具有下面的结构:SAAC·Fe·phen-(i-Bu)_3Al二元体系的催化效率是SAAC·Fe-phen-(i-Bu)_3Al三元体系的2倍,是小分子铁的400倍。在SAAC·Fe·phen和SAAC·Fe·Nphen体系中,当phen(或N pnen)/Fe的摩尔比为0.7左右时催化活性最高。催化活性随着Al/Fe摩尔比的增大而升高,但当Al/Fe摩尔比大于70以上活性趋于恒定,和小分子铁催化荆相比这种高分子铁催化剂可以提高聚合温度。     

双波长双指示剂-催化动力学光度法测定奶粉中的锌

研究发现在HCl介质中,痕量锌对H2O2氧化甲基紫和亚甲基蓝褪色具有强烈的催化作用,通过测量580 nm和668 nm处催化反应体系和非催化反应体系吸光度的变化,建立了双波长双指示剂催化动力学光度法测定痕量锌的新方法。在最佳实验条件下,线性范围为1.5~60μg/L,线性方程为ΔA=0.0169ρZn2+(μg/mL)+0.0019,r=0.9982,方法检出限为0.84μg/L。该方法可用于奶粉痕量锌的测定。     

锌-硫氰酸盐-结晶紫体系共振散射法测定痕量锌

在pH 5.0 NaAc-HAc介质和吐温80溶液中,研究了zn(SCN)42-与结晶紫形成的离子缔合微粒的共振散射光谱,考察了其各种影响因素和适宜的反应条件,确定了共振散射强度与Zn2+浓度的关系,建立了测定痕量zn(Ⅱ)的共振散射新方法.研究表明,在0.020～0.80μg/mL范围内,体系的共振散射强度△I与Zn...     

双波长双指示剂催化光度法测定铜的研究

研究了在pH 4.0的HAc～NaAc缓冲介质中,利用痕量铜(Ⅱ)催化过氧化氢氧化罗丹明B和亚甲基蓝褪色的指示反应,通过测量540 nm和660 nm下,催化体系和非催化体系吸光度的变化,建立了双波长双指示剂催化动力学光度法测定痕量铜的新方法.方法的线性范围为0.00080～0.048μg/mL,检出限为4.0×10~(-11) g/mL.方法可用于水中铜的测定.     

Catalytic spectrophotometric determination of molybdenum (VI) with the hydrazine-metanil yellow system

A new catalytic Spectrophotometric method for the determination of trace amounts of molybdenum (VI) has been proposed. The method is based on the catalytic effect of Mo(VI) on the reduction of metanil yellow by hydrazine dihydrochloride. Under experiment condition, the linear range of determination is 20–160 ng/mL for molybdenum and the detection limit is 11.2ng/mL. The method has been used to determine trace molybdenum in bean samples with the recovery of 96.0–99.0%, with relative standard deviations of 1.50–2.53%.     

酶催化动力学光度法测定锌

近年来酶法在分析测定方面的研究非常活跃,酶法测定锌已有报道,基本为终点测定法。本文中的研究是基于LDH催化下列反应：丙酮酸＋NADH=乳酸＋NAD^＋（氧化型烟酰胺腺嘌呤二核苷酸）,锌离子的存在对酶催化反应具有抑制作用,反应速度的变化率与锌离子的浓度呈相关关系,从而可测定试样中的锌离子含量。本方法不需要底物转变完全,与终点测定法相比,可减少测定时间并节省酶量。     

吖啶黄荧光光度法测定腺嘌呤

碱性条件下,痕量腺嘌呤使得吖啶黄在激发波长为454 nm、发射波长为509 nm处的荧光强度明显增强,由此建立了荧光光度法测定痕量腺嘌呤的新方法.方法的线性范围为0.2～3.0×10-4 g/L,检出限为1.83×10-5 g/L,方法用于维生素B4片剂中腺嘌呤的测定,回收率为99.6%～101.4%.     

双波长双指示剂催化光度法测定食品中痕量钒

研究了在0.2 mol/L柠檬酸介质中,利用钒酸根对溴酸钾氧化乙基紫和萘酚绿B褪色反应同时具有强烈的催化作用,通过650 nm和720 nm波长下测量催化体系和非催化体系的吸光度,建立了一种双指示剂、双波长催化动力学光度法测定钒(V)的新方法。最佳实验条件下,测定钒的线性范围为1.00~80.0μg/L,检出限为1.1×10-10g/mL。对20.0μg/L钒进行12次平行测定的相对标准偏差为2.2%。方法用于面粉和大米中痕量钒的测定,结果令人满意。     

聚乙二醇双水相萃取光度法测定锌

A novel method of extraction spectrophotometric determination of Zn~(2+) in aqueous two-phase system formed by polyethylene glycol-2000,sodium sulfate and zincon has been established.Amounts of PEG solution,zincon solution,sodium sulfate added and the acidity of the system were optimized.The interference effects of various coexistent ions and the method to remove the interference were investigated.The Zn-zincon complex that had been formed in the presence of H_2BO_3-Na_2B_4O_7 buffer solution at pH 7.4 was extracted into the upper PEG-rich phase,and the absorbance of the extracted complex in the upper PEG-rich phase was measured at 630 nm.The apparent molar absorptivity was 7.3 × 10~4 L / (mol·cm).Beer's law was obeyed over the range of 0～2.0 μg / mL Zn~(2+).The analytical results obtained for Zn~(2+) in water samples were in good agreement with values measured by atomic absorption spectrometry.     

Simultaneous spectrophotometric determination of Zinc(II) and Nickel(II) with 1-(2-pyridylazo)-2-naphthol

A new procedure for the simultaneous spectrophotometric determination of Zn(II) and Ni(II) with 1-(2-pyridylazo)-2-naphthol as chromogenic reagent has been developed. It is based on resolution of the mixed spectrum over the wavelength range 530–590 nm by applying a least-squares fitting program to standard spectra from each component. The spectra are recorded at an apparent pH of 5.0, provided by an acetate buffer in a mixed 6040 v/v 2-ethoxyethanol/water medium. The relative standard deviations for determination of 13.7 g of Ni and 31.0 g of Zn were 1.9 and 1.0%, respectively (8 replications). The method has been applied to the analysis of iron surfaces coated with a Zn-Ni alloy. The results are compared with those obtained by atomic-absorption spectrophotometry.     

Dynamic microwave-assisted extraction coupled with on-line spectrophotometric determination of safflower yellow in Flos Carthami

A rapid dynamic microwave-assisted extraction and on-line detection by spectrophotometry is proposed for the determination of safflower yellow in Flos Carthami. A high pressure and a peristaltic pump were used to deliver the solvent. A TM₀₁₀ microwave resonance cavity was applied to concentrate the microwave energy and the forward power about 60 W was enough for the extraction. Other extraction conditions also were examined and optimized. In this work, the extraction process can be monitored by measuring the absorption of safflower yellow in the extract, which would be convenient for rapid optimization of the extraction process. The detection and quantification limits are 8 and 27 μg mL⁻¹, respectively. The within-day and between-day precision (R.S.D.) are 1.6-3.2% and 2.8-4.2%, respectively. Compared with off-line detection, the proposed method may provide more rapid measurement and is more convenient for obtaining continuous measurements.