Determination of CO2(g) by enhancement of luminol—cobalt(II) phthalocyanine chemiluminescence: Analysis of atmospheric air and human breath

Two related continuous-flow sensing strategies are presented for the determination of CO2(g) in gas mixtures. A continuous monitoring scheme is described for the determination of the analyte in atmospheric air, and a discrete sample introduction approach for the determination of the same analyte in human breath. The same chemical system is used in both cases, which is based on the CO2(g) enhancement of luminol chemiluminescence in the absence of added oxidant and in the presence of cobalt(II) phthalocyanine complex as rate modifier. A specially designed reaction cell is at the heart of these determinations. The main analytical virtues of these approaches are simplicity, fast response, and a wide linear concentration range amenable to determination (in log-log relationships from about 50 ppm to 800 ppm v/v, and from 1% to 100% v/v CO2(g).