Liquid paraffin

About: Liquid paraffin is a research topic. Over the lifetime, 6185 publications have been published within this topic receiving 52956 citations.

A voltammetric biosensor based on ionic liquid/NiO nanoparticle modified carbon paste electrode for the determination of nicotinamide adenine dinucleotide (NADH)

Abstract: Herein we report a NiO/nanoparticles (NiO/NPs) modified carbon ionic liquid paste electrode (IL/NiO/NPs/CPE) was fabricated and used to investigate the electrochemical behavior of NADH in aqueous solution. The proposed sensor was prepared by mixing hydrophilic ionic liquid 1-methyl-3-butylimidazolium bromide, NiO/NPs, graphite powder and liquid paraffin together. The oxidation peak potential of NADH at the surface of the ionic liquid NiO/NPs carbon paste electrode appeared at 635 mV, which was about 70 mV lower than the oxidation peak potential at the surface of traditional carbon CPE under similar conditions. On other hand, the oxidation peak current was increased to about four times at the surface of IL/NiO/NPs/CPE compared to CPE. The linear response range and detection limit were found to be 0.03–900 μmol L−1 and 0.009 μmol L−1, respectively. IL/NiO/NPs/CPE was successfully applied for the determination of NADH in real samples such as water, serum and urine. The results showed that the proposed method is highly selective, sensitive with a fast response for NADH analysis.

Controlled Release of Oral Drugs from Cross‐linked Polyvinyl Alcohol Microspheres

Abstract: A new technique for the preparation of cross-linked polyvinyl alcohol (PVA) microspheres containing various drugs is described. An aqueous solution of PVA containing various concentrations of glutaraldehyde was dispersed as droplets in liquid paraffin using a suitable stabilizing agent. Cross-linking of PVA droplets with glutaraldehyde was induced by an acid catalyst (HCl) which was produced by the addition of small quantities of benzoyl chloride into the dispersion medium. Microspheres containing drugs such as aspirin, griseofulvin and nicotinic acid were prepared by carrying out the cross-linking reaction in the presence of such drugs. The drug release studies were carried out in simulated gastric and intestinal fluids without enzymes at 37 degrees C. It was observed that increase in the cross-linking density of the microspheres reduced the drug release rate considerably, suggesting that the release profiles could be controlled by changing the cross-linking density. It was also observed that a higher rate of release was obtained from smaller beads.

ZnO nanoparticle-modified ionic liquid-carbon paste electrodefor voltammetric determination of folic acid in food and pharmaceutical samples

Abstract: In this work, a ZnO/nanoparticles (NPs) modified carbon ionic liquid paste electrode (ZnO/NP/CILPE) was fabricated and used to investigate the electrochemical behavior of folic acid. ZnO/NP/CILPE was prepared by mixing hydrophilic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim]-[PF6])), ZnO/NPs, graphite powder, and liquid paraffin together. The fabricated ZnO/NP/CILPE showed great electrocatalytic ability to the oxidation of folic acid, and an irreversible oxidation peak appeared at 0.75 V (vs. Ag/AgCl) with improved peak current. Under the optimized conditions of pH 9.0, the plot of peak current vs. folic acid concentration consisted of two linear segments with slopes of 1.776and 0.033 μA/μM in the concentration ranges of 0.05–1.5 μM and 1.5–550.0 μM, respectively. The detection limit was 0.01 μM (3σ). The proposed sensor was successfully applied for the determination of folic acid in fortified food and pharmaceutical samples.