Headspace Gas Chromatographic Method for Carbonate Content Determination in Layered Double Hydroxides

The determination of carbonate content is the basic procedure for studies related to layer double hydroxides (LDHs). This paper reports a rapid and accurate headspace gas chromatographic (HS-GC) technique for the determination of carbonate content in LDHs. The content of carbonate was expressed by the amount of CO2 generated by the reaction of sulfuric acid and carbonate, which can be measured by HS-GC technique using a thermal conductivity detector. It was found that a complete conversion of carbonate to CO2 can be achieved at 45 degrees C for about 4 min and a sulfuric acid dosage of 200 mu L in the headspace vial. Under optimized conditions, the limit of detection and relative standard deviation of HS-GC method is 0.79 mu mol and 1 %, respectively.