Coulometric Determination of Sulphur Compounds Using the Induced lodine-Azide Reaction

Wydrukowano z dostarczonych Wydawnictwu UŁ gotowych materiałówThe review summarizes application of coulometry for determination of the sulphur compounds that induce the iodine-azide reaction. The article discusses advantages of the coulometric method. The influence of potassium iodide on induction coefficients is also described. Moreover, determination ranges of several inductors are presented and sensitivities of determination by different methods are compared.Zadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

Application of a Graphene Oxide–Carbon Paste Electrode for the Determination of Lead in Rainbow Trout from Central Europe

In the presented study, the content of lead in rainbow trout (Oncorhynchus mykiss) samples was examined. Rainbow trout were purchased in Prague (Czech Republic), Lodz (Poland) and Bratislava (Slovakia) from local fish shops and supermarkets belonging to popular chain stores. First, method for quantitative lead determination was developed with very good results (R 2 at 0.9997 in the range of 1.0 × 10−7–7.0 × 10−5 mol L−1 with limit of detection (LOD) and limit of quantification (LOQ) 2.18 × 10−8 and 7.24 × 10−8 mol L−1, respectively). Then, after mineralization, fish samples were analyzed using square wave anodic stripping voltammetry (SWASV) with a graphene oxide–carbon paste electrode (GO–CPE). Lead signals recorded on GO–CPE electrode were 15 % higher than those obtained on bare CPE. The coefficient of variation (CV) was found to be below 5 %. The selectivity of the proposed method was evaluated by the addition of selected heavy metals (zinc, copper, mercury, cobalt, nickel, iron) as possible interferents. Results were confirmed with reference method.Financial support of the grant 506/1123 from the Ministry of Science and Higher Education is gratefully acknowledged

Analysis of Organophosphorus Compounds. 1. Application of Iodine-Azide Reaction for Detection of Thiophosphoorganic Compounds in Thin-Layer Chromatography

Wydrukowano z dostarczonych Wydawnictwu UŁ gotowych materiałówZadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

Electrochemical Study of the Pesticide Methidathion at a Mercury Electrode under Cathodic Stripping Mode

Methidathion, a non-systemic organophosphorous insecticide and acaricide is studied at the hanging mercury drop electrode under cathodic stripping mode by means of cyclic and square-wave voltammetry (SWV). Its electrode reaction is analyzed in the light of recent theory of cathodic stripping processes of insoluble salts of SWV. Its complex electrode mechanism is described by an electrode reaction of a second order, complicated by adsorption of methidathion molecules on the electrode surface involving lateral interactions between each other. Moreover, under specific experimental conditions the electrode mechanism can be additionally complicated by multilayer formation on the electrode surface, as well as by a chemical transformation following the cathodic stripping process of the methidathion- mercury salt. Following the mechanistic study of the electrode reaction, a method for quantitative determination of methidathion is proposed applying SWV

Coulometric Titration of Thiols with Electrogenerated Chlorine

Coulometric titration of thiols with chlorine in solution containing different electrolytes has been performed. Optimum determination conditions have been found. The developed method was applied to the determinaton of mesna (0.2510 µmol), L-cysteine (0.252 µmol), mercaptosuccinic acid (0.52.5 µmol), 3-mercaptopropionic acid (0.428.3 µmol), cysteamine hydrochloride (0.53 µmol), carbimazole (0.252 µmol), thiopental (0.11 µmol), thioglycolic acid (0.8710 µmol), D-penicillamine (0.1255 µmol), L-glutathione (0.510 µmol) and mesna in pharmaceutical preparations (Mistabron and AntiUron). Determination error was below 1%. Przeprowadzono miareczkowanie kulometryczne tioli z u¿yciem chloru jako titranta w rodowisku ró¿nych elektrolitów. Opracowano optymalne warunki oznaczenia. Za pomoc¹ opracowanej metody oznaczono mesnê (0.2510 µmol), L-cysteinê (0.252 µmol), kwas merkaptobursztynowy (0.52.5 µmol), kwas 3-mercaptopropionowy (0.428.3 µmol), chlorowodorek cysteaminy (0.53 µmol), karbimazol (0.252 µmol), tiopental (0.11 µmol), kwas tioglikolowy (0.8710 µmol), D-penicyloaminê (0.1255 µmol), L-glutation (0.510 µmol) oraz mesnê w preparatach farmaceutycznych Mistabron i AntiUron. Opracowana metoda umo¿liwia oznaczanie tioli z b³êdem poni¿ej 1%

Electroanalysis of pindolol on a GCE modified with reduced graphene oxide

Publikacja w ramach programu Royal Society of Chemistry "Gold for Gold" 2014 finansowanego przez Uniwersytet ŁódzkiIn this work, the application of an innovative, environmentally friendly reduced graphene oxide–glassy carbon (RGO–GC) electrode is described. Using the RGO–GC electrode, basic electrochemical properties (such as the number of protons and electrons involved in an oxidation process, heterogeneous rate constant, diffusion coefficient and electron transfer coefficient) of pindolol (PND) were studied. It was observed that the indole moiety is a part of the pindolol molecule where oxidation takes place. Additionally, a square-wave stripping voltammetric method for the quantitative determination of PND was developed. The influence of various factors such as pH, buffer concentration and SWSV (square wave stripping voltammetry) parameters were studied. The best results in terms of signal shape and intensity were recorded in a BR buffer at pH 5.0. This electroanalytical procedure was used to determine pindolol on the RGO–GC electrode in a concentration range of 1 10 7 to 1 10 5 mol L 1. The precision, repeatability and accuracy of the method were checked. The detection and quantification limits were found to be 2.6 10 8 and 8.6 10 8 mol L 1, respectively. The method has been satisfactorily applied to the determination of pindolol in urine samples and pharmaceutical formulations

Voltammetric behaviour and quantitative determination of pesticide iminoctadine

Publikacja w ramach programu Royal Society of Chemistry "Gold for Gold" 2014 finansowanego przez Uniwersytet ŁódzkiIminoctadine (IOD) was determined in spiked river water samples by square wave voltammetry (SWV) using a cyclic renewable silver amalgam film electrode (Hg(Ag)FE). It was found that the compound can act as an electrocatalyst. In Britton–Robinson buffer at pH 6.5 a signal connected with the catalytic hydrogen evolution reaction was detected at 1.8 V versus Ag/AgCl. Validation of the method was carried out. The LOD and LOQ have been estimated to be 2.6 10 9 mol L 1 and 8.5 10 9 mol L 1 , respectively