3. Results and discussion
3.1. Method validation
The characteristics of the calibration curves, including regression
equations, correlation coefficients (r) and linear ranges as well as
LODs and LOQs were listed in Table 2. All the analytes showed good
linearity (r > 0.999) over the tested concentration ranges. The LOD
and LOQ ranged from 0.06 to 0.91 μg/mL and 0.20 to 2.84 μg/mL, respectively.
The relative standard deviation (RSD) values obtained for
the precision, repeatability and stability tests were all less than 2.5%,
as given in Table 2, which showed that the system was reliable for
chemical analysis of tea samples. The recovery method percentage
ranged from 95.3% to 97.3%, with RSD less than 2.2% as shown in
Table 2. Considering the results, the method was accurate enough.