Development of a Novel Sensor Based on Polypyrrole Doped with Potassium Hexacyanoferrate (II) for Detection of L-Tryptophan in Pharmaceutics

This study describes the development of a new sensor with applicability in the determination and quantification of yjr essential amino acid (AA) L-tryptophan (L-TRP) from pharmaceutical products. The proposed sensor is based on a carbon screen-printed electrode (SPCE) modified with the conductor polymer polypyrrole (PPy) doped with potassium hexacyanoferrate (II) (FeCN). For the modification of the SPCE with the PPy doped with FeCN, the chronoamperometry (CA) method was used. For the study of the electrochemical behavior and the sensitive properties of the sensor when detecting L-TRP, the cyclic voltammetry (CV) method was used. This developed electrode has shown a high sensibility, a low detection limit (LOD) of up to 1.05 × 10−7 M, a quantification limit (LOQ) equal to 3.51 × 10−7 M and a wide linearity range between 3.3 × 10−7 M and 1.06 × 10−5 M. The analytical performances of the device were studied for the detection of AA L-TRP from pharmaceutical products, obtaining excellent results. The validation of the electroanalytical method was performed by using the standard method with good results.

Single-Chamber Microbial Fuel Cells’ Behavior at Different Operational Scenarios

A Microbial Fuel Cell (MFC) is a process in which a microorganism respires and captures the electrons that normally passes through the electron transport system of the organism and produces electricity. This work intends to present the different operating parameters affecting the efficiency of a Microbial Fuel Cell (MFC) process. To study the performance of the process, various materials for the cathode and anode rods with similar size and chape including, copper, aluminum, carbon cloth, steel and brass were considered to determine the combination that leads to the best results. Moreover, different oxidizing agents such as Copper Sulphate and Potassium Hexacyanoferrate were considered. Furthermore, the effects of shapes, sizes and distance between electrodes on the current and voltage were investigated. The power outputs between electrochemical and microbial cells were recorded. In addition, the power, whether expressed as voltage or current, was measured at different conditions and different cell combinations. The power is directly related to the area, volume of the bacterial solution and supplying air and stirring.

Palladium-Catalyzed Cyanation under Mild Conditions: A Case Study to Discover Appropriate Substrates among Halides and Pseudohalides

A case study has been effectively carried out to identify a suitable substrate among halides and pseudohalides for the palladium-catalyzed cyanation reactions under mild conditions. Among the various substrates considered for evaluation, aryl pentafluorobenzenesulfonates and nonaflates were identified to be the best substrates when compared to corresponding halides and pseudohalides. The substoichiometric use of nontoxic, environmentally benign potassium hexacyanoferrate as a cyanide source and exceptionally milder conditions further highlights the significance of the protocol developed. A wide range of electronically biased and sterically challenging substrates provided the corresponding the nitriles in good to excellent yields.

Quantitative analysis by Raman spectroscopy using potassium hexacyanoferrate (III) as an internal standard

In this article we proposed a method for quantitative determination of active substance in pharmaceuticals via Raman scattering using potassium ferricyanide as internal standard. We approved this method in ketoprophenum quantitative determination in drug for veterinary use “Ketojekt”. The calculation of metrological requirements of procedures are established proposed method of calibration. Either we demonstrated the focalisation factor of laser beam affects on the method reproducibility. The method provides a precise, rapid, convenient to quantitative analysis that is more effective than the standard HPLC assay.