Simultaneous detection of anions and cations in mineral water by two dimensional ion chromatography.

A two dimensional ion chromatography (2D-IC) method was improved for the simultaneous determination of six cations and seven anions using one-valve switching after injection and conductivity detector. The trap conditions and valve-switch timing were optimized. The method has good accuracy and sensitivity for the simultaneous separation of inorganic anions and cations with a mean correlation coefficient of >0.99, repeatability of 0.60%-3.0% for eight replicates, reproducibility of 0.78%-3.1%, and spiked recovery rate of 88.7%-110%. The method was successfully applied to the analysis of inorganic anions and cations in four kinds of mineral water and can completely satisfy the demand of water quality monitoring.

Color and alcohol removal for the simultaneous detection of amino acids and sugars in wine by two-dimensional ion chromatography.

An effective pretreatment method for wine color removal by a PS-DVB SPE cartridge and online alcohol elimination by valve switching was presented. The optimum parameters for color removal were investigated: 40-µm and 100Å poly (styrene)-divinylbenzene (PS-DVB) (0.4g) was selected as the color removal material and 5mL of ethanol (10%) as the elution solvent for sample pretreatment under given condition. Moreover, an accurate and automated two-dimensional ion chromatography method for the simultaneous detection of amino acids and sugars was achieved with two valves after injection without alcohol interference. The method had a mean correlation coefficient of >0.99 and a repeatability of 0.92%-4.30% for eight replicates. The mean recovery of six red wine samples were 97.6%, 96.6%, 96.1%, 95.9%, 97.3% and 96.4% respectively. And this method successfully analyzed the amino acid and sugar contents of six wine samples of different origins.