baseline, (Fig. 1). The calibration curve was obtained by
plotting full range concentrations of standards versus the
absorbance. The minimum and maximum nitrogen dioxide
concentration range, which in the data was observed, was in
the ratio 1:200. The corresponding absorbance data were
obtained at 1380 cm−1 for a large number of standard series
with as little as 0.025 μg NO2
−
/ 0.1 g KBr and as high as 5 μg NO2
−
/
0.1 g KBr. The software Table Curve 2D v5.01.01 was used for
processing the obtained data. This absorbance versus concentration
plot shows a straight line (CNO2
−
=8.24 Abs+0.16; here Abs is
the absorbance value) with excellent correlation coefficient value
of 0.999. The slope and the intercept for this straight line were
0.1213 and 0.0197 respectively.