Table 2.
Intra-day and inter-day precision (RSD %) and accuracy (RE %) of the LC-MS/MS method for determination of NAG, Glu, and GABA in QC solutions (n = 6).
| Analyte | Nominal Concentration (ng/ml) | Intra-day | Inter-day | ||||
|---|---|---|---|---|---|---|---|
| Observed concentration (ng/ml) | Precision (RSD %) | Accuracy (RE %) | Observed concentration (ng/ml) | Precision (RSD %) | Accuracy (RE %) | ||
| NAG | 50 | 50.81 ± 1.56 | 3.07 | 1.63 | 50.67 ± 1.65 | 3.27 | 1.35 |
| 500 | 492.36 ± 14.91 | 3.03 | −1.53 | 499.79 ± 9.72 | 1.95 | −0.04 | |
| 5,000 | 5065.94 ± 71.49 | 1.41 | 1.32 | 5,036.24 ± 117.44 | 2.33 | 0.72 | |
| Glu | 50 | 51.03 ± 1.60 | 3.15 | 2.06 | 50.76 ± 2.18 | 4.29 | 1.53 |
| 500 | 483.84 ± 5.06 | 1.05 | −3.23 | 507.59 ± 14.54 | 2.87 | 1.52 | |
| 5,000 | 5295.54 ± 282.39 | 5.33 | 5.91 | 4,986.62 ± 143.07 | 2.87 | 0.27 | |
| GABA | 50 | 50.56 ± 1.22 | 2.14 | 1.12 | 50.69 ± 1.98 | 3.90 | 1.39 |
| 500 | 527.92 ± 38.58 | 7.31 | 5.58 | 504.00 ± 13.53 | 2.69 | 0.80 | |
| 5,000 | 5175.83 ± 267.90 | 5.18 | 3.52 | 5,001.52 ± 200.45 | 4.00 | 0.03 | |