Validation of the SIFT technique for trace gas analysis of breath using the syringe injection technique

Abstract

The selected ion flow tube (SIFT) is a technique originally developed for the determination of rate coefficients for gas phase reactions. Recently the SIFT has been applied to the detection of trace gases in air and breath. The SIFT method is capable of determining absolute partial pressures of trace gases in air without the need for calibration. However, it is necessary to show that SIFT determinations are of acceptable accuracy. This study reports the findings of a validation study in which eight trace gases in air, in the concentration range of 100 ppb-30 ppm, were simultaneously detected and quantified. In addition, the results of the measurement of the partial pressure of perchloroethylene (C2Cl4) on the breath of a volunteer some 16 h after a controlled exposure are reported. This study demonstrates that several gases in breath can be rapidly quantified from just a single exhalation.