流动注射化学发光法测定氨苄西林的研究

氨苄西林在NaOH溶液中降解后,其产物可在酸性条件下与KMnO4发生化学发光反应,甲醛的存在可使发光强度增强。据此,采用流动注射技术,建立了一种测定氨苄西林的化学发光分析法。方法的检出限为9.1×10-9g/mL,相对标准偏差为1.8%(n=11,ρ=3.4×10-6g/mL),线性范围为4.0×10-8~2.0×10-5g/mL。利用该法测定了氨苄西林胶囊中的氨苄西林,其回收率在87%~106%。     

流动注射化学发光法测定司帕沙星的研究

在酸性介质中,司帕沙星对NaNO2-H2O2发光体系有很强的增强作用,并且其增强化学发光强度与司帕沙星的物质的量浓度在一定范围内呈线性关系。基于此,采用流动注射技术,建立了一种简单、快速测定司帕沙星的方法。线性范围为1.0×10-7~8.5×10-4mol/L,检出限为6.5×10-8mol/L。利用该法测定了司帕沙星片剂中的司帕沙星,回收率在98.8%~104.4%之间。     

流动注射化学发光法测定佐米曲谱坦

在碱性条件下,佐米曲谱坦对鲁米诺-K3[Fe(CN)6]化学发光体系有较强的抑制作用,据此建立了佐米曲谱坦的流动注射化学发光分析法。该法的化学发光抑制值ΔI与佐米曲谱坦质量浓度在2.0×10-6~1.2×10-4g/mL范围内,呈良好的线性关系,检出限为7.6×10-7g/mL。对2.5×10-5g/mL佐米曲谱坦测定的相对标准偏差为1.2%(n=11)。方法适用于佐米曲谱坦片中佐米曲谱坦的测定。     

流动注射化学发光法测定那格列奈

在碱性介质中,那格列奈对Luminol-H2O2体系的化学发光有很强的抑制作用,据此建立了流动注射化学发光抑制法测定那格列奈的新方法.该法的化学发光抑制值△I与那格列奈的质量浓度在2.0×10-8～1.0×10-6 g/mL范围内,呈良好的线性关系,检出限为1.4×10-8 g/mL;对4.0×10-7 g/mL那格列奈连续进行11次平行测定,相对标准偏差为1.0%;通过对荧光光谱的研究,对机理进行了初步探讨.     

流动注射化学发光法快速测定化学需氧量

基于酸性K2 Cr2 O7在消解水体中的有机污染物时被还原为Cr(Ⅲ ) ,而Cr(Ⅲ )可以催化Luminol H2 O2 体系产生强的化学发光 ,建立了一种测定COD的流动注射化学发光法。本方法不需要催化剂 ,不需要长的消解时间 ,可以采用较低的酸度 ,适合于在线连续检测水体COD。本方法检测COD的线性范围为 2 0～1 0 0 0 0mg L ,检出限为 1 0mg L ,对 1 0mg LCOD的 1 1次平行测定的RSD小于5 %。方法已用于地表水样COD的测定。     

Chemiluminescence determination of carbofuran and promecarb by flow injection analysis using two photochemical reactions

A flow injection-chemiluminescent method for the determination of carbofuran and promecarb is proposed. The assay was based on the on-line conversion of the pesticides into methylamine by irradiation with UV light. The methylamine generated was subsequently reacted with tris(2,2'-bipyridine)ruthenium(III), which was generated through the on-line photo-oxidation of tris(2,2'-bipyridine)ruthenium(II) with peroxydisulfate. The emitted light showed a linear relationship with the concentration of the pesticide over the ranges 0.22-11.2 microg ml(-1) for carbofuran and 0.41-16.6 microg ml(-1) for promecarb. The repeatability was 1.6% expressed as relative standard deviation (n = 10) and the reproducibility, studied on five different days, was 2%. The sample throughput was 200 injections per h. The reliability of the method for routine analysis of these pesticides in water, soil and grains is demonstrated.     

Chemiluminescence system for automatic determination of chemical oxygen demand using flow injection analysis

A novel chemiluminescence (CL) system for automatic determination of chemical oxygen demand (COD) combined with flow injection analysis is proposed in this paper. In this system, potassium permanganate is reduced to Mn²⁺ which is first adsorbed on a strongly acid cation-exchange resin mini-column to be concentrated during chemical oxidation of the organic compounds at room temperature, while the excessive MnO₄⁻ passes through the mini-column to be waste, then the concentrated Mn²⁺ is eluted reversely and measured by the luminol-H₂O₂ CL system. The calibration graph is linear in the range of 4-4000 mg l⁻¹ and the detection limit is 2 mg l⁻¹. A complete analysis could be performed in 1.5 min including washing and sampling, giving a throughout of about 40 h⁻¹. The relative standard deviation was 4.4% for 10 mg l⁻¹ COD (n=11), 4.8% for 100 mg l⁻¹ COD (n=11). This CL flow system for determination of COD is very simple, rapid and suitable for automatic and continuous analysis. The presented system has been applied successfully to the determination of COD of water samples.     

试剂固定化的流动注射化学发光测定盐酸伊托必利

基于盐酸伊托必利在碱性条件下对铁氰化钾鲁米诺化学发光体系有较强的抑制作用,并采用离子交换固定法将鲁米诺和铁氰化钾全部固定在阴离子交换树脂上,联用流动注射技术建立了测定盐酸伊托必利的新方法。本法的线性范围为1.0~100.0μg/mL,检出限0.2μg/mL,对20μg/mL的盐酸伊托必利11次平行测定,其相对标准偏差为2.1%。单次测定在45 s内完成。此固定化柱可使用200次以上。可用于盐酸伊托必利片剂中盐酸伊托必利的质量检测。     

Chemiluminescence determination of sodium 2-mercaptoethane sulfonate by flow injection analysis using cerium(IV) sensitized by quinine

A flow injection method with chemiluminescence (CL) detection is proposed for the determination of sodium 2-mercaptoethane sulfonate (MESNA), a drug often used to reduce the urotoxic effects of antineoplastic alkylating agents. The procedure is based on the reaction of the thiol with Ce(IV) in a sulfuric acid medium and measurement of the CL intensity produced by quinine used as a sensitizer. The optimum conditions for CL emission were investigated. Using the CL peak height as the analytical parameter, MESNA was determined over the concentration range 0.29–2.21 ng (1.97–9.85 μg·l⁻¹) with a detection limit of 0.21 ng (1.38 μg·l⁻¹) and a relative standard deviation (R.S.D.) of 4.1%. The method was applied satisfactorily to the determination of MESNA in pharmaceutical preparations with percentages of recovery between 94 and 105.     

Chemiluminescence determination of indole derivatives in human body fluids and soil by flow injection analysis using potassium permanganate

A simple, sensitive and rapid flow-injection chemiluminescence (CL) method has been developed for the determination of indole derivatives including indole-2,3-dione (isatin) and indole-3-acetic acid (IAA), based on the increased CL reaction of potassium permanganate-formaldehyde system in acidic medium. Strong CL was observed when the indole derivatives were injected into the acidic potassium permanganate solution in a flow-cell. Under the optimum conditions, the linear range of the determination was 0.1–100.0 µM for isatin and 0.01–10.0 µM for IAA. The detection limit (3σ) was 10.0 nM for isatin and 1.0 nM for IAA. The method has been successfully applied to the determination of isatin in biological samples and of IAA in biological samples and soil extracts with satisfactory results.     

Chemiluminescence detection of sodium nitroprusside using flow injection analysis

A simple continuous-flow chemiluminometric method for the determination of 0.05-10 microg/ml of sodium nitroprusside is described. The method is based on the catalyses of luminol oxidation by hydrogen peroxide in alkaline medium. The method is sensitive and requires no sample pre-treatment and solutions can be analysed at a rate of 40 samples/hr with a relative error of about 1.18%. The method was satisfactory for the determination of sodium nitroprusside in a pharmaceutical preparation. The effect of some potential interferents is described.     

流动注射化学发光法测定盐酸美司坦

在碱性介质中,当把鲁米诺和KMnO4的混合溶液注入到盐酸美司坦溶液中时,会产生很强的化学发光现象。由此结合流动注射技术,建立了测定盐酸美司坦的流动注射化学发光新方法。该法的线性范围为2.0×10^-7-8.0×10^-6g/mL,检出限（3σ）为9×10^-8g/mL,对2.0×10^-6g/mL盐酸美司坦样品连续进行11次平行测定,其RSD为0.74%。已用于盐酸美司坦片剂中盐酸美司坦的测定。     

Determination of phenylephrine hydrochloride by flow injection analysis with chemiluminescence detection

A new method is proposed for the determination of phenylephrine hydrochloride by flow injection analysis with direct chemiluminescence detection. The method is based on the oxidation of the drug by potassium permanganate in sulfuric acid medium at 80 degrees C. The calibration graph is linear over the range 0.03-8 ppm phenylephrine hydrochloride, with a relative standard deviation (n = 51, 0.5 ppm) of 1.1% and sample throughput of 134/h. The influence of 38 different foreign compounds was tested, and the method was applied to the determination of phenylephrine hydrochloride in 8 different pharmaceutical formulations.     

Chemiluminescence determination of nitrate with photochemical activation in a flow injection system

A chemiluminescence flow injection system is described for the determination of nitrate, involving use of a laboratory-built flow-through photochemical reactor. Optimum analytical conditions were established. The linear range for nitrate is 7 x 10(-8)-1 x 10(-4)M. The sampling frequency is 60 samples per hour. The relative standard deviation for 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5)M nitrate is 0.97, 0.84 and 0.76%, respectively. The method has been applied to the determination of nitrate in natural water samples, and recoveries of 96-103% have been attained.     

Chemiluminescence for the determination of traces of cobalt(II) by continuous flow and flow injection methods

Flow injection analysis, with chemiluminescence detection, is used to determine traces of cobalt(II) by means of the gallic acid—hydrogen peroxide—sodium hydroxide system containing a small amount of methanol to increase the sensitivity. This permits the determination of cobalt(II) more selectively than any other chemiluminescent system with a detection limit of 0.04 μg l^-1 (continuous sample flow) or 0.04 ng (10-μl sample injection). The linear range is 3 orders of magnitude, the sampling rate is 20 h^-1, and the relative standard deviation is 5.9% for 0.06 ng Co(II) (n = 10). Silver(I), the strongest enhancer after cobalt(II), provides a signal 1.3% of that for Co(II). A few precipitants and complexing agents suppress the signal.     

Chemiluminescence detection flow cells for flow injection analysis and high-performance liquid chromatography

We have examined a range of new and previously described flow cells for chemiluminescence detection. The reactions of acidic potassium permanganate with morphine and amoxicillin were used as model systems representing the many fast chemiluminescence reactions between oxidising agents and organic analytes, and the preliminary partial reduction of the reagent was exploited to further increase the rates of reaction. The comparison was then extended to high-performance liquid chromatography separations of α- and β-adrenergic agonists, with permanganate chemiluminescence detection. Flow cells constructed by machining novel channel designs into white polymer materials (sealed with transparent films or plates) have enabled improvements in mixing efficiency and overall transmission of light to the photodetector.     

Spectrophotometric determination of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride by flow injection analysis.

1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC.HCl) is a very useful agent to form amide bonds (peptide bonds) in an aqueous medium. A simple and fast detection system was developed using the reaction with pyridine and ethylenediamine in acidic aqueous solution and spectrophotometric flow injection analysis. The absorbances were measured at 400 nm and the reaction was accelerated at 40 degrees C. The calibration graph showed good linearity from 0 to 10% of EDC.HCl solutions: the regression equation was y=3.15x10(4)x (y, peak area; x, % concentration of EDC.HCl). The RSD was under 1.0%. Sample throughput was 15 h(-1). This method was applied to monitoring the EDC.HCl concentration that remained after the anhydration of phthalic acid in water, esterification of acetic acid in methanol or dehydration condensation of malonic acid and ethylenediamine in water.     

Chemiluminescent determination of pyridoxine hydrochloride in pharmaceutical samples using flow injection

A chemiluminescent method using flow injection is described for the determination of pyridoxine hydrochloride. Its detection limit, linearity and reproducibility were examined. The method is based on the enhancing effect of pyridoxine hydrochloride on the chemiluminescence generated by the oxidation of luminol with hydrogen peroxide in aqueous potassium hydroxide and sodium oxalate. The proposed method is simple and inexpensive. The chemiluminescence intensity is a linear function of pyridoxine hydrochloride concentration over the range 10–250 μg ml⁻¹ with a detection limit of 6 μg ml⁻¹. The applicability of the method was demonstrated by the determination of pyridoxine hydrochloride in different tablet formulations and some dietary sources.