Selective removal of carbon dioxide contained in the effluent from ion chromatography suppressors using a new non-vacuum device.

Abstract In this paper, a new CO 2 gas removal device optimized to selectively remove CO 2 gas contained in the effluent from suppressors used in ion chromatography (IC) under non-vacuum conditions is described. This device consists of a closed vessel equipped with gas permeable tubing (GPT) and a CO 2 adsorbent. During operation, the CO 2 adsorbent adsorbs CO 2 gas in the vessel, creating CO 2 partial pressure difference between the inside of the GPT and the vessel. The CO 2 gas contained in the effluent being pumped into the GPT is selectively removed from the effluent based on the diffusion of the CO 2 associated with the CO 2 partial pressure difference. The purpose of this study is to optimize the IC operating conditions with the aim of selectively removing HCO 3 − (CO 3 2− ) contained in the effluent and reducing the electrical conductivity of the effluent under non-vacuum conditions. The electrical conductivity of the effluent and the signal intensity of the water dip is decreased by approximately 25 μS/cm (from 30 to 5 μS/cm) and by approximately twentieth, respectively, using the optimized CO 2 remover. In addition, the anion detection limit achieved in IC instruments with a CO 2 remover is on the order of a few ppb.