Entacapone Levodopa Carbidopa
% Level Concen-tration (ppm) Area % Level Concen-tration (ppm) Area % Level Concen-tration (ppm) Area
50 50.33 1644591 12 12.08 105951 12 3.05 19826
60 60.39 1974936 25 24.17 211972 24 6.09 40184
66 66.43 2161375 50 50.35 436302 50 12.69 83963
75 74.48 2445512 75 74.52 631283 75 18.78 124561
100 100.65 3276792 100 100.70 860553 100 25.38 167461
120 120.78 3943031 120 120.84 1020742 120 30.46 201900
150 150.98 4926510 150 151.05 1295253 150 38.07 253235
Slope 2590.1783 Slope    8494.4494 Slope    6650.2203
Y-Intercept5024.5917 Y-Intercept   4069.0608 Y-Intercept     493.9482
Correlation coefficient 1.000 Correlation coefficient 0.9998 Correlation coefficient 1.0000
Table 7: Linearity results of the proposed method.