The limit of detection (LOD) defined as 3 N/S (N refers to
thenoise andS refers to the slope ofthe calibrationcurve) was about
6.0 ppm (benzene) and 7.8 ppm (toluene), respectively, which was
below the standard permitted concentrations. Moreover, the
relative standard deviation (R.S.D. n = 7) for 100 ppm benzene and
toluene was 4.2% and 3.5%, respectively, which showed a good
repeatability and linearity of this determination method