Current Analytical Chemistry - Volume 5, Issue 3, 2009

An indirect flow injection spectrophotometric procedure for the determination of ranitidine in pharmaceutical formulations is proposed. The method was based on the oxidation of the ranitidine with cerium(IV) in acidic medium and subsequent determination of cerium(IV) excess by reaction with ferroin which was monitored spectrophotometrically at 500 nm. The linearity of the analytical curve for ranitidine ranged from 2.5 x 10- Read More

Sample treatment/preparation procedures using octadecylsilane as common phase for solid-phase extraction (SPE) and solid-phase microextraction (SPME) were compared for the analysis of the pesticides pyrimethanil, kresoximmethyl and tebufenpyrad in water samples. SPE and SPME were followed by gas chromatography-mass spectrometry (GC-MS). SPE require 500 mL of sample and leads to a limit of det Read More

Carbohydrates exhibit many physiologically and pharmacologically important activities, yet their complicated structure and sequence pose major analytical challenges. Although their structural complexity makes analysis of carbohydrate difficult, mass spectrometry (MS) with high sensitivity, resolution and accuracy has become a vital tool in many applications related to analysis of carbohydrates or oligosaccharides. This appli Read More

This paper describes a method for voriconazole assay in pharmaceuticals by using differential pulse polarography (DPP). The voriconazole standard was obtained from pharmaceutical formulations and its purity determined by LC/UV, LC/ESI/MS and DSC analyses. In the DPP analysis a well defined peak (-1.01 V, vs. Ag/AgCl), useful for an accurate and precise assay, was obtained using a 0.01 M KH2PO4 water solution (pH 4.5) as su Read More

The electrochemical behavior of Zinc(II)-furdap amide complex has been investigated by the use of several electrochemical methods in DMSO on platinum electrode. Both the ligand and the complex gave one electron transfer reduction. Although there was no oxidation peak observed corresponding to the reduction of ligand, there was a corresponding oxidation peak appeared for the complex. The number of electrons Read More

Supramolecular ionophores have in the few past years gained increasing interest in the field of analytical chemistry because of their large varieties and applications in chemical sensors. Calixarenes are considered an important class of supramolecular compounds used in construction of many electrochemical sensors in the past years. This review discusses the main applications of calixarenes in the assay of pharmaceutical, bio Read More

The production of volatile organic compounds (VOC) by plants is well known. However, few scientific groups have studied VOC produced by green, brown and red algae. Headspace collection of volatiles and solid phase microextraction, as well as the traditional extraction by hydrodistillation combined with analytical chromatographic techniques (i.e., GC-MS), have significantly improved the investigation of VOC from plants an Read More