Quantitation by Portable Gas Chromatography: Mass Spectrometry of VOCs Associated with Vapor Intrusion

Table 5

Audit accuracy.

Compound	Concentration of standard (ppbv)	Calculated concentration (ppbv)	Replicate precision (% difference)	Percent audit accuracy (% difference)
Methylene chloride	173	128	2.52	25.9
Trichloroethylene	45.8	40.6	4.04	11.3
Tetrachloroethylene	16.2	13.1	3.16	19.6
Toluene	74.3	88.3	2.09	18.8
o, m, p-Xylenes	89.4	91.3	4.71	2.91