Development of Flow Injection Analysis with Electrochemical Detection for a Urease Breath Test Based on Ammonia

摘要

Introduction. The high urease activity of the Helicobacter pylori organism has led to the development of diagnostic tests that rely on the presence of urease breakdown products, CO2 and NH3, to serve as an indicator of active infection. Noninvasive breath tests based on CO2, using isotopically labeled [13C] urea have been shown to have excellent test characteristics. However, the [13C] urea breath test is relatively expensive. Measurement of ammonia in the breath formed by the action of the Helicobacter pylori urease enzyme has received relatively little study in human. Ammonia is normally present in the breath at very low concentrations of 100-2000 parts per billion (ppb) as part of a complex mixture of volatile organics, making measurement difficult and unreliable with conventional sensors. Therefore, a simple, reliable, and rapid assay for detemining ammonia in breath is desirable in the analysis of clinical field.