Chemiluminescence determination of tiopronin by flow injection analysis based on cerium(IV) oxidation sensitized by quinine

Graphene quantum dots as nanosensor for rapid and label-free dual detection of Cu2+ and tiopronin by means of fluorescence “on–off–on” switching: mechanism and molecular logic gate

(A) Schematic diagram of the interaction and dual detection of Cu2+ and MPG by means of fluorescence “on–off–on” switching. (B) Molecular logic gate and truth table constructed based on Cu2+ and MPG as inputs and emission signal as output.

Energy transfer processes of chemiluminescence reaction systems with cerium(IV) ions and their analytical application: a review

This review is devoted to a thorough discussion of chemiluminescence of the systems containing Ce(IV) ions as oxidising agents, with particular emphasis on the energy transfer processes in such systems. The influence of sensitisers such as: rhodamines, quinine, lanthanide ions and their complexes and quantum-dots has been analysed and the practical use of reaction systems for development of new chemiluminescence methods for determination of therapeutic drugs and substances of biological importance in different matrices such as human urine or serum is indicated. The types of emitters and excited reaction products taking part in energy transfer to sensitisers and processes taking place in the chemiluminescence reaction systems containing Ce(IV) ions are presented on the basis of recent literature.

Fast determination of thiacloprid by photoinduced chemiluminescence

A new and sensitive application of chemiluminescence detection has been developed for the determination of the pesticide thiacloprid in water. It was based on the on-line photoreaction of thiacloprid in a basic medium, with quinine acting as the sensitizer of the chemiluminescent response; cerium (IV) in sulfuric acid medium was used as the oxidant. High degrees of automation and reproducibility were achieved using a flow-injection analysis (FIA) manifold. The validation of the method was performed in terms of selectivity, linearity, limit of detection (LOD), precision, and accuracy. Liquid chromatography with ultraviolet (UV) detection was used as reference for mineral, tap, ground, and spring water samples. The proposed method is fast (with a throughput of 130 h(-1)), sensitive (LOD of 0.8 ng mL(-1) without preconcentration steps and of 0.08 ng mL(-1) with solid-phase extraction [SPE]), low cost, and possible to couple with separation methods for the simultaneous determination of other pesticides. The enhanced chemiluminescence intensity was linear with the thiacloprid concentration above the 2-80 and 80-800 ng mL(-1) ranges. A possible reaction mechanism is also discussed.

Spectrophotometric determination of N-acetyl-L-cysteine and N-(2-mercaptopropionyl)-glycine in pharmaceutical preparations

A simple spectrophotometric method for the determination of N-acetyl-L-cysteine (NAC) and N-(2-mercaptopropionyl)glycine (MPG) in pharmaceutical preparations was developed, validated, and used. The proposed equilibrium method is based on a coupled two-step redox and complexation reaction. In the first step, Fe(III) is reduced to Fe(II) by NAC or MPG. Subsequently, Fe(II) is complexed with 2,4,6-tripyridyl-s-triazine (TPTZ). Several analytical parameters of the method were optimized for NAC and MPG analysis in the concentration range from 1.0 μM to 100.0 μM. Regression analysis of the calibration data showed a good correlation coefficient (0.9999). The detection limit of the method was 0.14 μM for NAC and 0.13 μM for MPG. The method was successfully applied to quantify NAC and MPG in pharmaceutical preparations. No interferences were observed from common pharmaceutical excipients.

A simple and sensitive chemiluminescence method for the determination of tiopronin for a pharmaceutical formulation

Here we report a rather simple and convenient chemiluminescence (CL) method for the determination of tiopronin. It was based that tiopronin could greatly enhance CL between H2O2 and luminol in a basic alkaline solution. Light emission is intense, and even with a simple setup a high sensitivity could be achieved. The linear range was 3 mM-500 nM with a detection limit of 200 nM. Singlet oxygen and hydroxyl radical were suggested to be produced in this reaction and was responsible for the CL of tiopronin. As a preliminary application, this simple method has been successfully applied into the determination of tiopronin in a pharmaceutical formulation.

A novel chemiluminescence method for determination of terbutaline sulfate based on potassium ferricyanide oxidation sensitized by rhodamine 6G

This work reports a novel flow injection-chemiluminescence (FI-CL) system for determination of terbutaline sulfate, a drug for treatment of asthma and chronic obstructive pulmonary disease (COPD). It is based on the reaction of potassium ferricyanide with terbutaline sulfate in sodium hydroxide medium sensitized by the fluorescent dye rhodamine 6G. With the peak height as a quantitative parameter applying optimum working conditions, terbutaline sulfate is determined over the range of 0.01-1.2 microg ml(-1) with a detection limit of 6.7 x 10(-3) microg ml(-1). The relative standard deviation (R.S.D.) is 3.7% for 0.1 microg ml(-1) terbutaline sulfate (n = 11). The proposed method is sensitive, simple, rapid, and was applied to determination of terbutaline sulfate in pharmaceutical preparations. The possible chemiluminescence (CL) reaction mechanism was also discussed briefly.

Flow-chemiluminescence: a growing modality of pharmaceutical analysis

The present article deals with a review of the applications of the chemiluminescence to pharmaceutical analyses by using continuous-flow assemblies. A comprehensive study on the fundamentals of the chemiluminescence is also included.

Determination of tiopronin in pharmaceuticals using a chemiluminescent flow-injection method

A flow-injection method for the determination of tiopronin in the range 1 x 10(-7)-7 x 10(-5) M is described. The procedure is based on the chemiluminescent reaction of tiopronin with cerium(i.v.) in sulphuric acid medium using rhodamine 6G and quinine as fluorophors. The flow-injection method is rapid and precise and allows measurements of up to 80 solutions per hour. The applicability of the method to the determination of tiopronin in pharmaceutical preparations was demonstrated by investigating the effect of potential interferences and by analysing commercial preparations.