分光光度法测定发样中的微量铁

在表面活性剂OP存在下，利用硫氰酸钾和罗丹明B与铁的显色反应，建立了测定发样中微量铁离子含量的分光光度法。在OP溶液浓度为1.0g／L、酸度为4mmol／L的硫酸介质中，于580nm波长处，铁含量在0-0．8μg／mL范围内符合比尔定律，线性回归方程为A=1．403c 0．0114，相关系数r=0．9992，回收率为93．6％-107．1％，该法的分析结果与原子吸收分光光度法基本一致。     

火焰原子吸收分光光度法测定铜合金中的铁

研究了火焰原子吸收分光光度法测定铜合金中铁含量的方法,对仪器工作条件如灯电流、光谱通带、空气和乙炔流量进行了分析。铁的质量浓度在0-5mg／L内与吸光度呈良好的线性关系,线性方程为A：0．03179c＋0．004098,相关系数,r=0．9996,检出限为0．009mg／L。用该方法对4种铜合金标准物质进行测定,测定结果与标准值相符,相对标准偏差分别为0．54％,0．78％,0．10％,2．07％0=6）。     

分光光度法同时测定铝质耐火材料中的铁和钛

建立了同时测定铝质耐火材料中铁和钛的方法。以二安替比林甲烷(DAM)为显色剂，在盐酸介质中，显色剂分别与Ti(IV)、Fe(Ⅲ)生成有色络合物，采用双波长法同时测定该两种元素。铁含量的线性范围为0-0．01mg／mL，相关系数r=0．9998；钛含量的线性范围为0—0．002mg／mL，相关系数为r=0．9999。该方法可用于Fe2O3含量大于或等于0．005％、TiO2含量大于或等于0．001％的铝质耐火材料中铁和钛的同时测定。     

6-氯吲哚酮的含量测定研究

以无水乙醇作为溶剂,用紫外分光光度法测定盐酸齐拉西酮的重要中间体6-氯吲哚酮的含量．测得6-吲哚酮对照品溶液浓度在0．0048～0．0200mg／mL范围之内线性关系良好,其线性方程为Y=41．484X＋0．007（R^2=0．9994）．平均回收率为99．11％,RSD为0．53％（n=6）,结果说明方法简便、灵敏、准确,重现性好．     

双波长分光光度法测定阿丙沙星可溶性粉中阿莫西林、盐酸环丙沙星的含量

应用双波长分光光度法测定阿丙沙星可溶性粉中阿莫西林、盐酸环丙沙星的含量。以pH=5．0的磷酸盐缓冲液为溶剂,在波长229、248、315、400nm处进行测定,阿莫西林的浓度在5．130～25．650μg／mL、盐酸环丙沙星的浓度在4．888～24．440μg／mL范围内分别与其吸光度差值呈良好的线性关系。阿莫西林的回收率为99．30％～100．19％,测定结果的相对标准偏差为0．60％～1．00％(n=5),盐酸环丙沙星的回收率为99．30％～99．86％,测定结果的相对标准偏差为0．84％～1．02％(n=5)。     

离子色谱法测定粮食鲜样中的硝酸盐含量

粮食鲜样经超声提取后，用离子色谱法测定浸提液中的硝酸盐。采用DX-100型离子色谱仪．以2．7mmol／L Na2CO3—0．3mmol／LNaHCO3的混合溶液作为淋洗液，流速为1．2mL／min，测定玉米、大豆、小麦中的NO3^-含量。NO3^-浓度在0．5—40．0mg／L范围内与色谱峰高呈良好的线性关系，相关系数r=0．9995，检出限为0．05mg／L，测定结果的相对标准偏差小于5％．加标回收率为96．0％-100．7％。     

火焰原子吸收光谱法连续测定香蕉中的铜铁锌锰

研究了香蕉中的金属元素的含量和火焰原子吸收光谱法在同一体系中测定香蕉中微量元素铜、铁、锌、锰的方法，考察了硝酸、过氧化氢的不同用量以及消化时间长短的影响和在同一体系中铜、铁、锌、锰的相互干扰情况。在选定条件下铜检测限为0．064μg／mL，铁为0．275μg／mL，锌为0．157μg／mL，锰为0．187μg／mL，相对标准偏差为1．9％-4．7％，回收率为92．3％-105．0％。     

亚甲蓝分光光度法测定水体中的阴离子表面活性剂

利用三氯甲烷萃取水体样品中的阴离子表面活性剂，用50mL比色管代替50mL容量瓶对三氯甲烷萃取液进行定容，以亚甲蓝分光光度法进行测定。该方法操作简便，测定阴离子表面活性剂的线性范围为0．150～1．70mg／L，检出限为0．050mg／L，样品加标回收率为89％～98％。     

流动注射分光光度法间接测定利血生制剂中利血生的含量

提出了利血生的流动注射分光光度间接分析方法。以水作载液，可间接测定利血生的含量。测定的线性范围0．01－0．2mg/mL。回收率为100．0％－102．0％。     

淮安市1684名中小学生血清钙、铁、锌含量分析

为了解淮安地区中小学生血清中钙、铁、锌含量情况,应用改进的火焰原子吸收光谱法对1684名对象的血清中相关元素的含量进行了测定。结果表明,该地区3种元素总体水平在正常范围内,钙、铁、锌血清含量分别为（102．69±26．30）mg／L、（1．01±0．61）mg／L、（0．86±0．45）mg／L;性别、城乡差别无统计学意义（P〉0．05）;而年级的差别有统计学意义（P值均〈0．0001）,初中组各元素水平明显高于小学组。     

硝普钠分光光度法测定头孢他啶

建立了硝普钠分光光度法测定头孢他啶的方法。实验结果表明,在碱性条件下,头孢他啶与硝普钠以1∶2的化学计量比反应形成一种红褐色产物,其最大吸收波长为528 nm。 头孢他啶在2.50~810 mg/L浓度范围内与吸光度呈良好线性关系,线性回归方程为A=0.02704+0.00218ρ(mg/L),线性相关系数r＝0.9987,表观摩尔吸收系数ε528=1.2×103 L/(mol·cm),检测限(3σ/k)为1.38 mg/L。 本方法操作简便、快速,成功用于药品中头孢他啶含量的测定。     

A Novel Visible Spectrophotometric Method for the Determination of Methanol Using Sodium Nitroprusside as Spectroscopic Probe

A novel, rapid and reliable method has been established for the determination of methanol using sodium nitroprusside as a spectroscopic probe. This method indicates that the sodium nitroprusside can react with the methanol to form a colored product in the basic solution. The absorbance of the product is measured at the maximal absorption wavelength of 481 nm, and the amount of methanol can be calculated based on this absorbance. A good linear relationship of the concentration of methanol versus absorbance is observed with a linear range of 0.02‐6.0 mg mL^?1. The linear regression equation is A = 0.02484 + 0.29457C (mg mL^?1), with a correlation coefficient of 0.9991. The detection limit (3σ/k) is 0.012 mg mL^?1, while its R.S.D. is 1.5% and the recovery rate is 97.5‐102.5%. The parameters with regard to determination are optimized, and the reaction mechanism is discussed. This method has been successfully applied to determine methanol in variety of samples. Analytical results obtained by this new method were very gratifying.     

Determination of low concentrations of acetaldehyde in ethylene oxide

The method is based on a qualitative test for acetaldehyde in which the reagents sodium nitroprusside and piperidine react with acetaldehyde to form a coloured substance that can be determined photometrically. This substance is unstable, however, and after reaching a maximum value in about 25 sec the absorbance decreases. Ethylene oxide also reacts with sodium nitroprusside to form brownish substances, but this reaction is slower, the colour not developing for 100–120 sec. If, therefore, the absorbance is measured about 25 sec after adding the reagents, any disturbance from the ethylene oxide is avoided.     

Assay of Phenformin Hydrochloride in Pharmaceutics by Coupling with Sodium Nitroprusside

A novel and simple spectrophotometric method for the determination of phenformin hydrochloride using sodium nitroprusside as chromogenic reagent is developed in this paper. The experiment indicates that the sodium nitroprusside can react with the phenformin hydrochloride in a basic solution to form a product with colored N‐nitrosamines. The stoichiometric ratio of phenformin hydrochloride and sodium nitroprusside is 1:3 in the product. The maximal absorption wavelength (λ_max) of the product is 520 nm, ?₅₂₀ = 2.2 × 10³ Lmol^?1cm^?1. A Good linear relationship is obtained between the absorbance (A) and the concentration (C) of phenformin hydrochloride in a wide range of 0.20‐400 μg mL^?1. The equation of the linear regression is A = 0.03461 + 0.00907C (μg mL^?1) with a linear correlation coefficient of 0.9991. The detection limit is 0.13 μg mL^?1, and the relative standard deviation (R.S.D.) is 0.19%. The method is successfully applied to the determination of phenformin hydrochloride in tablet forms, and satisfactory recoveries are obtained.     

在丙酮增敏作用下硝普钠分光光度法测定盐酸吗啉胍

摘要：建立了可见分光光度法测定盐酸吗啉胍的新方法。研究表明,当NaOH浓度为0.13mol/L,在丙酮存在下硝普钠与盐酸吗啉胍反应生成紫色N-亚硝基类化合物,其最大吸收波长为508nm,表观摩尔吸光系数2.5×10³ L/（mol•cm）。盐酸吗啉胍浓度在0.38×10^-6~3.0×10^-4 g/mL范围内与吸光度呈现良好线性关系,线性回归方程A = 0.02292 + 0.01213c (10^-6 g/mL),线性相关系数r=0.9998,检测限(3σ/k)为0.25×10^-6 g/mL,RSD = 0.21%。本方法可用于药物样品和血清中盐酸吗啉胍含量的测定。     

Selective spectrophotometric determination of paracetamol with sodium nitroprusside in pharmaceutical and biological samples

A novel simple method to determine paracetamol with good selectivity has been established by using sodium nitroprusside as the chromogenic reagent. The experiment indicates that sodium nitroprusside can react with paracetamol in a basic solution to form a product with colored O-nitrosamines. The maximal absorption wavelength (λ_max) and the apparent molar absorption coefficient of the product are 700 nm and 3.4 × 10³ L/mol cm, respectively. A Good linear relationship is obtained between the absorbance and the concentration of paracetamol in a wide range of 0.19–96 μg/mL. The linear regression equation is A = 0.01695 + 0.02240C (μg/mL), with a correlation coefficient of 0.9993. The detection limit (3σ/κ) is 0.10 μg/mL, and the relative standard deviation (RSD) is 0.90% (n = 11). The parameters with regard to determination are optimized, and the reaction mechanism is discussed. The method has been successfully applied to the selective determination of paracetamol in pharmaceutical and biological samples.     

Re-examination of the determination of ammonium as the indophenol blue complex using salicylate

The most sensitive spectrophotometric procedure for the determination of ammonium is based on the conversion of ammonium into the intense blue indophenol complex (IPC) by means of salicylate and nitroprusside. Optimization of concentration, preparation and timing of the addition of reagents, reaction temperature and protection from light increased the conversion of ammonium into IPC by about 50% compared with existing methods. The absorbance was 0.60 at a concentration of 20 nmol of ammonium per millilitre of final solution (RSD of the manual procedure=0.6%; n=10) with a detection limit of 0.4 μM in samples.     

Rapid and Convenient Method for the Determination of Sodium Nitroprusside in Aqueous Solution

Abstract

We propose a rapid and convenient method for the determination of sodium nitroprusside in aqueous solution. In alkaline medium and in the presence of dimethylsulfoxide, the concentration of the nitrite ions coming from the nitroprusside corresponds with the initial quantity of this compound.     

Factorial analysis optimization of a Diltiazem kinetic spectrophotometric quantification method

A Diltiazem kinetic spectrophotometric method was optimized by factorial analysis. The experimental method is based on a two-stage reaction of Diltiazem with hydroxylamine and a ferric salt: in the first stage there is a hydroxamic acid formation; and, in the second stage there is a red colour complex ferric hydroxamate formation. The variables under investigation were: solvent; hydroxylamine, sodium hydroxide and ammonium ferric sulphate concentrations; volume of perchloric acid; and, temperature. The responses of the reactional system were the maximum absorbance, the wavelength and the reaction time at maximum absorbance. Experimental design methodologies were used in the optimization. Fractional and full factorial designs followed by optimization Box-Behnken and central composite experimental designs were used. The observed optimum conditions were: methanol as reaction solvent; hydroxylamine concentration of 9.375%; sodium hydroxide concentration of 18.750%; ferric reagent concentration of 2.000%; minimum volume of perchloric acid to neutralize the sodium hydroxide; and, room temperature as reaction temperature. With this set of experimental conditions a reaction time of 10.5 s with maximum colour development at 512 nm wavelength was achieved.     

总氮测定过程中空白吸光值偏高的原因分析

使用HJ 636-2012测定水质总氮时,空白吸光值往往偏高。为了寻找最佳的实验条件,使用多元线性回归模型定性评价过硫酸钾和氢氧化钠的纯度、实验用水、碱性过硫酸钾溶液的存放时间、消解条件、冷却时间、消解器皿等因素对空白吸光值的重要性。结果表明:过硫酸钾纯度对空白吸光值影响最显著。为了保证总氮空白吸光值小于0.030,测定总氮时应优先使用经过2~3次重结晶的过硫酸钾以及优级纯的氢氧化钠,碱性过硫酸钾溶液应现配现用;建议消解时间30 min,消解温度123℃,自然冷却时间1.5 h;实验应优先使用超纯水或无氨水;使用哈希消解管代替25 mL比色管。