Table 1.
Accuracy, precision, recovery and matrix effect for analysis of gallic acid (GA) and protocatechuic acid (PCA) in quality control samples (n = 6).
| Analyte | Spiked concentration (μg/L) | Intra-day |
Inter-day |
Recovery (%, means ± SD) | Matrix effect (%, means ± SD) | ||
|---|---|---|---|---|---|---|---|
| Accuracy (%) | Precision (%) | Accuracy (%) | Precision (%) | ||||
| GA | 1.00 | −5.13 | 7.04 | −3.14 | 9.36 | – | – |
| 3.00 | −3.62 | 1.53 | −3.98 | 2.62 | 99.22 ± 3.62 | 109.27 ± 5.77 | |
| 60.0 | −2.98 | 2.44 | −3.38 | 3.13 | 92.49 ± 2.01 | 103.11 ± 0.51 | |
| 300.0 | −7.41 | 0.95 | −6.87 | 1.93 | 91.08 ± 2.37 | 102.36 ± 0.47 | |
| PCA | 0.50 | −4.29 | 9.06 | −8.54 | 9.98 | – | – |
| 1.50 | −6.93 | 2.46 | −7.01 | 4.01 | 99.79 ± 3.34 | 111.65 ± 8.18 | |
| 30.0 | −5.56 | 2.07 | −5.03 | 2.63 | 92.49 ± 2.45 | 101.39 ± 0.51 | |
| 150.0 | −5.54 | 1.42 | −6.39 | 1.74 | 92.26 ± 2.21 | 101.40 ± 0.74 | |