Faster assay of H2 in breath by dedicated instruments compared with conventional gas chromatography.

Recently available instruments dedicated to the clinical assay of hydrogen in breath were tested and the results compared with those from a conventional thermal conductivity gas chromatograph. We found the Quintron Model 12 Microlyzer and the GMI Exhaled Hydrogen Monitor to give much faster and more sensitive results than the Gow-Mac 550 conventional gas chromatograph, and their readout is digital rather than graphical. Linearity of response, accuracy, and precision were similar for all those instruments. Maintenance requirements and performance characteristics of the three instruments are compared in detail and practical advice is given on daily operation.