Diltiazem-tetraiodide bismuthate (III) based PVC membrane for selective determination of diltiazem hydrochloride

Ryad Kassab — 2023-03-06

A new coated-wire electrode based on PVC membrane plasticized with dioctyl phthalate (DOP) and containing the diltiazem-tetraiodido bismuthate (III) ion association coated on a silver wire was constructed and used for potentiometric determination of diltiazem hydrochloride. The electrode performance was characterized and optimized according to the following experimental criteria: membrane composition, soaking time, working pH range, and response time. The interference caused by different species was investigated as well. The best membrane composition was found to be 49.75% of PVC and DOP, 0.5% ion pair. This sensor showed a linear response with a good Nernstian slope of 57.60±1.38 mV/decade over the concentration range
5.0×10-5 – 2.50×10-2 M, the detection limit was 2.88×10-5 M, and it was usable within a wide pH range of
2.5–8.0. The electrode showed a fast response time (18 sec), with a relative long lifetime (2.4 months, 2 h a day). The isothermal coefficient (dE°/dT) of the electrode was calculated and found to be 5.36×10-4 V/℃ within
20 – 80℃, which exhibits a good thermal stability. The coted-wire electrode was successfully applied for the potentiometric determination of diltiazem hydrochloride both in pure form and pharmaceutical preparations. The dissolution test of the drug was carried out as well.

Synthesis of Heptylalkanoyldisulfides and Investigation of Their Antimicrobial Properties

Fuad Aliyev — 2023-09-15

The paper describes the results of the research of some heptylalkanoyldisulfides as antimicrobial additives to the lubricating oils. Heptylalkanoyldisulfides were synthesized and studied. The synthesized compounds were characterized by spectroscopic techniques. Study of antimicrobial properties of the studied heptylalkanoyldisulfides revealed effective bactericidal and fungicidal activities in suppression of fungi and bacteria allowing them to be used as biocides in storage and transportation of oil products. Antimicrobial efficacy of the studied compounds was determined by zonal diffusion method using the following microorganisms: bacteria, fungi and yeast. The test compounds were added to M-8 oil in mass percent. It is established that their antimicrobial activity is at the level of effectiveness of the widely used industrial additive sodium pentachlorophenolate. Sodium pentachlorophenolate, widely applied as an antimicrobial additive in lubricating oils, was used for comparison. It was determined that they may be used as antimicrobial additives for M-8 engine oil (0.25-1%). As a result of the studies carried out on heptylalkanoyldisulfides, distinct patterns of dependence of antimicrobial efficacy on the structure of alkyl radical were determined. Antimicrobial activity increases by an increase in alkyl radical, i.e., each subsequent member of the disulfide series is biologically more active than the previous one. The increase in antimicrobial activity seems to be due to the fact that the adding each new CH2 group gives one more van der Waals bond, increasing adsorption forces that bind the compound to the receptor in the microorganism. As a result of the studies carried out on heptylalkanoyldisulfides, distinct patterns of dependence of antimicrobial efficacy on the structure of alkyl radical were determined

JOURNAL OF ADVANCES IN CHEMISTRY

Diltiazem-tetraiodide bismuthate (III) based PVC membrane for selective determination of diltiazem hydrochloride

Synthesis of Heptylalkanoyldisulfides and Investigation of Their Antimicrobial Properties