CHEMOMETRICS ASSISTED UV-SPECTROPHOTOMETRIC ...

Fig.24. Box plot for salicylic acid with resorcinol mixture .................................................30
Fig.25. Scree plot for salicylic acid with resorcinol mixture...............................................30
Fig.26. The degree of overlapping between benzoic and salicylic acid ..............................31
Fig.27. The degree of spectral overlapping between
salicylic acid and resorcinol......................................................................................32
Fig.28. First derivative spectra of pure benzoic acid at
different concentration levels...................................................................................33
Fig.29. First derivative spectra of pure salicylic acid at
different concentration levels...................................................................................33
Fig.30. First derivative spectra for benzoic acid and salicylic acid
indicating the zero-crossing points of each of them .................................................34
Fig.31. First derivative spectra of resorcinol at different
concentration levels ..................................................................................................38
Fig.32. First derivative spectra for salicylic acid resorcinol, indicating the
zero-crossing points of each of them ........................................................................38
Fig.33. Benzoic acid spectral ratio (divisor is 25 µg of
salicylic acid at 3 nm difference intervals) .............................................................43
Fig.34. Benzoic acid derivative ratio ( divisor is 25 µg
salicylic acid at 2 nm difference intervals) .............................................................44
Fig.35. Salicylic acid spectral ratio (divisor is 50 µg/ml
benzoic acid at 4 nm difference intervals) ...............................................................44
Fig.36. Salicylic acid derivative ratio (divisor is 50 µg/ml
benzoic acid at 4 nm difference intervals) ..............................................................45
Fig.37. Salicylic acid spectral ratio (divisor is 25 µg/ml
resorcinol at 3 nm difference intervals) .................................................................49
Fig.38. Salicylic acid derivative ratio (divisor is 25 µg/ml
resorcinol at 3 nm difference intervals) .................................................................49
Fig.39. Resorcinol spectral ratio (divisor is 5 µg/ml
salicylic acid at 1 nm difference intervals) ............................................................50
Fig.40. Resorcinol derivative ratio (divisor is 5 µg/ml
salicylic acid at 1nm difference intervals) ............................................................50
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