an ion chromatography (ic) method for simultaneous determination of benzoic, salicylic and sorbic acids was developed. in this method the samples were purified by solid-phase extraction. the analytes were then eluted with methanol from c18 cartridge. the separation was performed on ion-exclusion column by an isocratic elution with 0.25 mmol /l sulfuric acid solution containing 20% (v/v) acetone...

an ion chromatography (ic) method for simultaneous determination of benzoic, salicylic and sorbic acids was developed. in this method the samples were purified by solid-phase extraction. the analytes were then eluted with methanol from c18 cartridge. the separation was performed on ion-exclusion column by an isocratic elution with 0.25 mmol /l sulfuric acid solution containing 20% (v/v) acetone...

Two detection systems for gas-liquid chromatography were compared for the identification of metabolic end products (short-chain organic acids) from anaerobic bacteria. Argon and flame ionization detectors were connected in series with inert argon as the carrier gas for analysis of 35 stock strains and 148 clinical isolates. There was an excellent correlation between the argon and flame ionizati...

A microfabricated electrophoresis chip with an integrated contactless conductivity detection system is described. The new contactless conductivity microchip detector is based on placing two planar sensing aluminum film electrodes on the outer side of a poly(methyl methacrylate) (PMMA) microchip (without contacting the solution) and measuring the impedance of the solution in the separation chann...

We discuss the characterization of phantom materials that simulate the electromagnetic characteristics of various human tissues from 100 Hz to 10 MHz, and over a temperature range of 15 C to 40 C. The materials studied were: 1) a solution of potassium chloride in water, 2) a solution of propylene carbonate, ethylene carbonate, and salts, 3) a semi-solid material consisting of silicone and carbo...

A capacitively-coupled contactless conductivity detector (C4D) has been utilised as an on-capillary detector within a capillary ion chromatograph, incorporating a reversed-phase monolithic silica capillary column semi-permanently modified with a suitable ionic surfactant. The monolithic capillary column (150 x 0.1 mm i.d.) was modified using sodium dioctyl sulfosuccinate (DOSS), an anionic surf...

A capacitively coupled contactless conductivity detector produced in Low Temperature Co-fired Ceramic (LTCC) technology for microchip capillary electrophoresis (CE) is reported in this work. Electrodes located outside the measurement channel are used to sense impedance variations caused by conductive ions. The application of LTCC in combination with contactless conductivity detection is very pr...

INTRODUCTION Accurate measurement of dielectric constant and conductivity, also known as, Electrochemical Impedance Spectroscopy (EIS) is a simple, yet powerful technique for analyzing the properties of liquids and gases. EIS is currently used in a wide range of industrial applications including monitoring the purity of boiler water in power plants [1], as well as, the health of lubricants in h...