3. Results and discussion
3.1. Calibration curve and detection limit
The calibration curve was constructed by plotting the peak area
ratio of BA or SA and the internal standard CA against the concentration
of BA or SA. Excellent linearity was obtained within the
concentration range of 20–100 mg/L (the wavelength used to perform
the calibration was 225 nm), giving both samples a correlation
coefficient of 0.9996.
The detection limit of BA, SA and CA was found to be 0.2, 0.1 and
0.5 mg/L respectively in the final solution when the signal-to-noise
ratio was greater than 3:1.