AN APPROACH TO TEST RELATIVE RECOVERY RATE BETWEEN DIFFERENT STANDARD PHASES IN THE ANALYSIS OF VOCS USING THERMAL DESORBER - GAS CHROMATOGRAPHY - MASS SPECTROMETRY

Abstract

The focus of this paper is to assess the relative performance of thermal desorber gas chromatography mass spectrometry (TD-GC-MS) between liquid and gaseous phase calibration of VOCs. The calibration results derived by the standards of two different phases indicate an excellent linearity property (e.g., r(2) > 0.99), although the sensitivity of the liquid phase standard was generally nearly 2-fold enhanced relative to those of the gaseous counterpart. The results of this comparison suggest that the use of gas phase standard can suffer from systematic loss in sensitivity relative to the liquid phase standard. In spite of these differences, both methods exhibited similar results in terms of their basic quality assurance (QA). It is thus recommended that the pattern of bias due to phase difference should be defined, if quantification of airborne VOCs is made by standards prepared in different types of media (i.e., liquid phase).