Reverse micelle‐based chemiluminescence system for quinine sulphate

Abstract

A new chemiluminescence (CL) method is proposed for the determination of quinine sulphate, which is based on the dichloromethane solvent extraction of the ion-pair complex of tetrachloroaurate (III) with quinine sulphate, and luminol CL detection in a reversed micellar medium formed by the cation surfactant cetyltrimethylammonium bromide in a dichloromethane-cyclohexane (3:7, v/v)-water (0.35 mol/L Na2CO3 buffer solution, pH 11.5). The ion-pair complex of tetrachloroaurate (III) with quinine sulphate produced an analytical CL signal when it entered the reversed micellar water pool. In optimum conditions, CL intensities are proportional to the concentrations of the studied drug over the range 0.015-10 microg/mL, with a detection limit of 1.5 ng/mL. The relative standard deviation (RSD) is 1.38% for 2.5 microg/mL quinine sulphate (n=11). The method has been applied to the determination of the studied drug in biological fluids, with satisfactory results.

Copper thiocyanato complexes and cocaine – a case of ‘black cocaine’

“…Thus, the acetone-soluble material contains Cu 2+ and Fe 3+ ions, SCN À and CocH + which strongly reminds to the above mentioned procedures for the extraction and detection of cocaine and related atropine bases using anionic thiocyanate metal complexes such as [Cr(SCN) 6 ] 3À , [Fe(NCS) 6 ] 3À , [3,5,6] [Fe(NCS) 4 ] À , [11] [Co(SCN) 4 ] 2À , [2,4,6] [Ni(SCN) 4 ] 2À , [6] but also [BiI 4 ] À (Dragendorff reagent), [6] or [AuCl 4 ] À . [26,27] The anionic complexes form tight ion-pairs with the protonated atropine bases (or related molecules), allowing the selective liquid-liquid extraction using organic solvents.…”

Automatic miniaturized flow methodology with in-line solid-phase extraction for quinine determination in biological samples

“…11,12,23 However, in recent years new outbreaks of chloroquine-resistant strains of malaria are guiding the driving forces behind the renewed interest in the use of the naturally occurring alkaloid quinine in the treatment of this parasitical disease. 19 Recently, two flow injection analysis methods with chemiluminometric detection for the determination of quinine were developed 13,14 with detection limits identical to those achieved here. However the former 13 requires an off-line organic solvent liquid-liquid extraction before the introduction to the flow system, besides the use of the organic solvent extractor as a carrier, and the latter one 14 comprises a protein precipitation step and subsequent centrifugation within the sample pretreatment.…”

“…These methods include high-performance liquid chromatography (HPLC) procedures using normal 9 or reversed-phase columns after liquid-liquid/solid extraction of the drug and either ultraviolet 10 or fluorescence detection. 11,12 Chemiluminometric, 13,14 capillary electrophoresis, 15 gas chromatography 16 and thin layer chromatography 17 methods have also been developed. However, some procedures involve high-cost equipment and are time consuming with low sampling throughput, requiring sample pre-treatment (including most of the time extraction with organic solvents).…”

Plastic Membrane Electrodes of Coated Wire Type for Micro Determination of Quininium Cation in Pharmaceutical Tablets

“…Several analytical methods have been developed for the quantitative determination of this drug. These methodologies include chromatography (Samanidou et al, 2005;2004), spectrophotometry (Csernak et al, 2006;Hassan, 2008;Tang et al, 2005;Radhi et al, 2010).…”