CHEMOMETRICS ASSISTED UV-SPECTROPHOTOMETRIC ...

0.1
0.0
0.0
0.0
-0.0
-0.0
-0.1
-0.1
215 220 225 230 235 240 245 250 255 260 265
Fig.36. Salicylic acid derivative ratio (divisor is 50 µg/ml benzoic acid at 4 nm difference
intervals).
Linear relationships between the derivative ratio amplitudes as each of benzoic and salicylic
acid concentrations were obtained over the used concentration ranges (5-50 µg/ml).
Derivative ratio spectra values for benzoic acid at 269.5 nm and for salicylic acid at 292.5 nm
and 308.5 nm were used for all calculations of concentrations of benzoic acid and salicylic
acid in all the subsequent work: linear regression ranges, slopes, intercepts, correlation and
determination coefficients, limits of detection (LOD, µg/ml) and limits of quantification.
(LOQ, µg/ml) for both compounds are shown in the following tables (Tables 7-9).
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