流动注射分光光度法测定番茄中维生素C的含量

在酸性介质中维生素C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510 nm,通过测定Fe(Ⅱ)的量间接的测定维生素C的量.基于此,结合流动注射分析技术,建立了测定维生素C含量的新方法.在0.08～50 μg/mL范围内呈良好的线性关系,线性回归方程为ΔA=-0.00203 +0.0...     

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。     

反相高效液相色谱-增敏化学发光同时测定VB1和VC

本文基于维生素B1(VB1)、维生素C(VC)对鲁米诺(Luminol)和铁氰化钾(K3[Fe(CN)6])化学发光反应的增敏作用原理,建立了反相高效液相色谱(RP-HPLC)分离、柱后化学发光检测VB1与VC的新方法。当在鲁米诺中加入KBr时可以大大增敏该反应。本法已成功运用于蜂蜜和复合维生素片中VB1与VC的测定。     

邻菲哕啉-Fe(Ⅱ)光度法间接测定盐酸吡硫醇

在酸性介质中,盐酸吡硫醇可将Fe(Ⅲ)还原为Fe(Ⅱ),邻菲啰啉能与Fe(Ⅱ)显色,最大吸收波长为508 nm,通过测定Fe(1Ⅰ)的量间接的测定了盐酸吡硫醇的量.建立了测定盐酸吡硫醇质量浓度的新方法.盐酸吡硫醇在0.010～6.0 μg/mL范围内与吸光度呈良好的线性关系,线性回归方程为△A=-0.00373+0.1...     

Fe(Ш)-磺基水杨酸褪色光度法测定甲巯咪唑

建立了Fe(Ш)-磺基水杨酸褪色光度法测定甲巯咪唑的方法。结果表明,在酸性介质中,甲巯咪唑分子中的巯基(-SH)可将Fe3+还原为Fe2+,采用磺基水杨酸作为Fe3+的显色剂,借褪色分光光度法间接测定了甲巯咪唑含量。显色体系最大吸收波长为480nm,甲巯咪唑质量浓度在0.072～0.156 mg/mL范围内与吸光度A呈良好的线性关系,线性回归方程为A=-0.1548ρ+0.0949,线性相关系数r=0.9988。方法用于实际药品中甲巯咪唑的含量测定,结果与药典法一致。     

偶合化学发光法测定环境水样中的痕量亚硝酸根

将亚硝酸盐在酸性条件下氧化亚铁氰化钾为铁氰化钾的反应 ,和尿酸 铁氰化钾 鲁米诺化学发光反应偶合一起 ,建立了一种间接测定亚硝酸根离子的新方法。讨论了酸度、反应物浓度、干扰离子等因素的影响。方法的检出限为5 .0× 1 0 - 1 1 g/mL ,对环境水样样品进行了平行测定 (n =1 1 ) ,其相对标准偏差为1 .8%～ 3 2 % ,线性范围为 1 .0× 1 0 - 9g/mL～ 1 .0× 1 0 - 5g/mL ,回收率为 94.3%～ 1 0 5 3%。     

铁氰化钾-Fe(Ⅲ)分光光度法测定盐酸氯丙嗪

建立了以铁氰化钾-Fe(Ⅲ)体系测定盐酸氯丙嗪的新方法.研究表明,盐酸氯丙嗪可以使Fe(Ⅲ)还原为Fe(Ⅱ),还原生成的Fe(Ⅱ)可以与K3[Fe(CN)6]反应生成可溶性普鲁士蓝KFe[Fe(CN)6].盐酸氯丙嗪的质量浓度在0.21-32.00μg/mL范围内与吸光度呈现良好线性关系,线性回归方程A=0.01854+0.07652p(μg/mL),相关系数R=0.9992,摩尔吸光系数ε=2.5×10(4)·L·mol-1·cm-1,检出限0.12μg/mL.方法用于测定药物和血清中盐酸氯丙嗪含量,回收率为98.1%～101.3%.     

铁氰化钾分光光度法测定药物中维生素B_1含量

在NaOH碱性介质中,维生素B1能将K3[Fe(CN)6]定量还原为K4[Fe(CN)6],根据Fe3+与K4[Fe(CN)6]反应生成可溶性普鲁士蓝的吸光度值,可间接测定出维生素B1的含量。在选定条件下,维生素B1在0.40~15.0mg·L-1范围内与吸光度(A)呈线性关系,相关系数R=0.9989,检出限为0.12mg·L-1,相对标准偏差(RSD)为1.75%(n=6)。表观摩尔吸光系数ε=4.3×104 L·mol-1·cm-1。该方法可用于药物中维生素B1含量的测定。     

差示分光光度法测定茶多酚的含量

基于茶多酚在酸性条件下还原 Fe3+ 为 Fe2 + ,Fe2 + 与铁氰化钾生成可溶性兰色配合物 KFe[Fe (CN) 6 ],用差示分光光度法测定其吸光度 ,从而可间接测定茶多酚的含量。方法线性范围为 2μg/m L～ 1 2μg/m L ,ε=1 .97× 1 0 5L· mol- 1· cm- 1,RSD=1 .3 % (茶多酚含量 8μg/m L,n=1 1 )。测定结果与标准方法基本一致     

铁(Ⅱ)-铁氰化钾阻抑光度法测定消毒液中过氧乙酸

在H2SO4介质中,过氧乙酸对Fe(Ⅱ)-铁氰化钾显色反应有明显的阻抑作用。据此建立Fe(Ⅱ)-铁氰化钾阻抑光度法测定过氧乙酸的新方法。测得最大吸收波长为720nm,过氧乙酸浓度在6~50μmol/L范围内与吸光度递减呈良好的线性关系。方法的相对标准偏差为2.9%~4.2%;回收率为95.8%~96.7%。方法已用于测定消毒液中微量过氧乙酸。     

Formation of ferricyanides-I silver(I), copper(II) and cadmium(II)

With potassium ferricyanide copper(II) forms KCu(10),[Fe(CN)(6)](7) quantitatively in 0.5M potassium nitrate medium. Cadmium forms Cd(3)[Fe(CN)(6)](2) if the ferricyanide is added to the cadmium solution in absence of extra potassium, and KCd(10)[Fe(CN)(6)](7) if potassium is added first, or if the cadmium solution is added to the ferricyanide. Silver forms Ag(3)Fe(CN)(6) only.     

氢化物发生—原子荧光法测定地球化学样品中痕量铅

研究了铁氰化碱性体系下痕量氢的化物发生－原子荧光测定的方法。本方法克服了在酸性样品溶液中加入铁氰化钾后对样品分析产生的问题，具有操作简便。分析结果重现性好等特点。对二十六个国家一级地球化学标准物质进行了分析，获得满意结果。     

Simultaneous reduction of arsenic and lead to hydrides by sodium tetrahydroborate(III) for inductively coupled plasma-atomic emission spectrometry: An investigation into the reaction medium

Nitroso R salt and potassium ferricyanide, in hydrochloric acid, have been used as the reaction medium for simultaneous generation of arsine and plumbane, combined with inductively coupled plasma-atomic emission spectrometric detection. Both of the reagents enhance the lead signal and neither reagent inhibits the arsenic signal, provided that the potassium ferricyanide is mixed on-line with the analyte solution. Potassium iodide, which is used to prereduce As(V) to As(III), does not interfere with plumbane generation in both reaction systems. Various parameters affecting the signals have been studied, and the hydrochloric acid-potassium ferricyanide system has proved to be a better reaction medium. Detection limits of lead and arsenic are 1.1 and 2.8 ng/ml, respectively, have been obtained in the HClK(3) Fe(CN)(6) system at a sample uptake rate of 1.5 ml/min.     

用铁氰化钾分光光度法测定头孢噻肟钠

建立了以铁氰化钾测定头孢噻肟钠的分光光度法。 在0.20 mol/L NaOH溶液中,头孢噻肟钠(CTX)于100 ℃水浴中降解生成的巯基化合物能将Fe(Ⅲ)(pH=3.0)还原为Fe(Ⅱ),根据Fe(Ⅱ)与K3[Fe(CN)6]反应生成可溶性普鲁士蓝(KFeⅢ[FeⅡ(CN)6])的吸光度,可以间接测定头孢噻肟钠的含量。 头孢噻肟钠在0.040~24 mg/L范围内与吸光度(A)呈线性关系,线性回归方程:A=0.05088+0.2166ρ(mg/L),相关系数R=0.9986,检出限为0.01 mg/L,相对标准偏差(RSD)为1.36%(n=11),表观摩尔吸光系数ε=2.3×105 L/(mol·cm)。 此方法可用于药物及血清中头孢噻肟钠含量的测定。     

New reactions of nickel and cobalt with iron-cyanogen compounds and a new method of determination of ferricyan

Nickel ferrocyanide in presence of acids is oxidised by the oxygen of the air to nickel ferricyanide. Cobalt ferrocyanide is oxidised under the same conditions to a ultramarine blue substance with a slight grayish tinge. This substance is very similar to Prussian blue and to Turnbull's blue and could be called cobalt Prussian blue. This blue substance is also formed if mixtures of potassium ferrocyanide and potassium ferricyanide are precipitated with an excess of cobalt salt. This investigation led to the conclusion that the blue substance is probably not a mere mixture of cobalt ferrocyanide and cobalt ferricyanide. but the compound 6 Co₂[Fe(CN)₆]. Co₃[Fe(CN)₆]₂. A new method of the determination of ferricyan is described. Moreover, it was proved that some statements of former investigators on the reactions of nickel and cobalt with iron-cyanogen compounds are erroneous, and some iron-cyanogen compounds of nickel and cobalt described in the literature do not exist at all.     

A Novel Spectrophotometric Method for the Determination of Levodopa with the Detection System of Potassium Ferricyanide‐Fe(III)

In this paper, a novel method has been established to determine levodopa with the detection system of potassium ferricyanide‐Fe(III). In the presence of potassium ferricyanide, it has been demonstrated that Fe(III) is reduced to Fe(II) by levodopa at pH 4.0. In addition, the in situ formed Fe(II) reacts with potassium ferricyanide to form soluble prussian blue (KFe^III[Fe^II(CN)₆]). Beer's law is obeyed in the range of levodopa concentrations of 0.01–4.00 μg mL^?1 at the maximal absorption wavelength of 735 nm. The linear regression equation is A = 0.0082 + 0.61365 C (μg mL^?1) with a correlation coefficient of 0.9996. The detection limit (3σ/k) is 9 ng mL^?1, and R.S.D. is 0.73% (n = 11). Moreover, the apparent molar absorption coefficient of indirect determination of levodopa is 1.2 × 10⁵ Lmol^?1cm^?1. The parameters with regard to determination are optimized, and the reaction mechanism is discussed. This method has been successfully applied to determine levodopa in pharmaceutical, serum and urine samples. Analytical results obtained with this novel assay are satisfactory.     

Potentiometric determination of potassium ferricyanide

A rapid and accurate electrometric method for the determination of potassium ferricyanide solutions has been investigated. It consists in titrating ferricyanide solutions potentiometrically against standard AgNO₃, using a silver indicator electrode in conjunction with a saturated calomel electrode connected by a KNO₃ bridge. Either of the reagents may be used as the titrant. A marked change in e.m.f is observed at thc end-point corresponding to the formation and precipitation of Ag³[Fe(CN)₆]. The curves have a regular form, a pronounced maximum in dE/dV occurs at the end-point and the results are very accurate and reproducible. The reaction, though simple, affords a quantitative method for the determination of ferricyanide or silver. The effect of neutral salts and ethanol on the accuracy of the end-point has been studied.     

Flow injection spectrophotometric determination of vitamin E in pharmaceuticals,milk powder and blood serum using potassium ferricyanide-Fe(Ⅲ) detection system

<正>A simple and sensitive flow injection spectrophotometric method is reported for the determination of vitamin E using potassium ferricyanide-Fe(Ⅲ) detection system.In the presence of vitamin E,Fe(Ⅲ)/ferricyanide reduces.The in situ reduced ions are then reacted with unreduced portion of ferricyanide/Fe(Ⅲ) to make soluble Prussian blue,which is monitored at absorption wavelength of 735 nm.Linear calibration graph was obtained in the concentration range of 0.1-40μg mL~(-1).The relative standard deviations (n=4) were in the range of 1.1-3.6%,with limits of detection(3 s blank) of 0.04μg mL~(-1).The proposed method allowed 12 injections h~(-1).The method is applied to determine vitamin E in pharmaceuticals,infant milk and blood serum samples using hexane extraction with the recoveries in the range of 93±3 to 97.5±4%.The method is validated using certified reference materials SRM 968c for blood serum samples.     

基于碳纳米管修饰电极的胆碱电化学发光生物传感器研制

在碳纳米管(CNTs)和K3Fe(CN)6修饰的铂电极上吸附固定胆碱氧化酶,以鲁米诺为发光试剂,研制了胆碱电化学发光(ECL)生物传感器。CNTs可有效提高电极表面的电荷传输能力、提高电极表面的生物相容性和对酶分子的固载能力;K3Fe(CN)6对酶活性具有激活作用,同时对H2O2增敏的鲁米诺ECL有增强作用,均有利于提高传感器的检测灵敏度。研究表明,将CNTs分散液与K3Fe(CN)6混合,滴涂修饰在Pt电极上,吸附固定胆碱氧化酶,制备传感器。此传感器在含有8×10-6mol/L鲁米诺的磷酸盐缓冲液(pH7.4)、30℃条件下产生的ECL强度与胆碱浓度在1×10-7～4×10-3mol/L范围内呈线性关系,相关系数为0.994,检出限为1.2×10-8 mol/L。此生物传感器应用于鼠血样中胆碱的测定,测得结果为2.68 mg/L,平均回收率为101.1%。传感器具有快速、稳定和重现性好等特点,有望应用于常规分析。     

A novel method for the determination of tiopronin by using potassium ferricyanide as spectroscopic probe reagent in pharmaceutical and urine samples

In this paper, a novel method has been established to determine tiopronin using potassium ferricyanide as spectroscopic probe reagent. It has been demonstrated that Fe(III) is reduced to Fe(II) by tiopronin, and the in situ formed Fe(II) reacts with potassium ferricyanide to form soluble Prussian blue. Beer’s law is obeyed in the range of tiopronin concentration of 0.040–9.00 μg/mL at the maximal absorption wavelength of 735 nm. The linear regression equation is A = 0.0153 + 0.1605c (μg/mL) with a correlation coefficient of 0.9997 and the apparent molar absorption coefficient of 2.6 × 10⁴ L/mol cm. The detection limit is 0.030 μg/mL and RSD is 1.3%. The parameters with regard to determination have been optimized and the reaction mechanism has been discussed. This method has been successfully applied to determine tiopronin in pharmaceutical and urine samples with satisfactory results.