Table 4.
Signal-to-noise ratios (mean ± SD) of the lowest standard curve concentrations and goodness of standard curves.
| Analyte | C (μg/L) | S/N (mean) | SD | Δnom.conc. (mean. %) | SD | Slope (mean) | SD | r2 |
|---|---|---|---|---|---|---|---|---|
| Choline | 5.0 | 127 | ±19 | 99.5 | ±0.14 | 1.02 | ±0.023 | 0.997 |
| PCho | 15 | 404 | ±42 | 95.9 | ±0.13 | 1.00 | ±0.018 | 0.998 |
| GPCho | 10 | 146 | ±14 | 94.9 | ±0.12 | 1.00 | ±0.008 | >0.999 |
| Betaine | 1.0 | 11 | ±1.6 | 98.7 | ±0.01 | 0.98 | ±0.023 | 0.995 |
| Carnitine | 1.0 | 34 | ±2.2 | 98.4 | ±0.12 | 1.01 | ±0.007 | >0.999 |
| Creatinine | 1.0 | 13 | ±0.8 | 95.2 | ±0.13 | 1.00 | ±0.010 | 0.999 |
| DMG | 1.0 | 163 | ±21 | 100.0 | ±0.08 | 0.96 | ±0.016 | 0.998 |
| Methionine | 1.0 | 213 | ±16 | 96.4 | ±0.11 | 0.99 | ±0.010 | 0.999 |
| TMAO | 1.0 | 38 | ±4.3 | 101.3 | ±0.08 | 0.97 | ±0.020 | 0.996 |
Signal-to-noise ratios were determined in replicates of three. Goodness of the standard curves was evaluated using eight curves acquired over 1 month. DMG, dimethylglycine; GPCho, glycerophosphocholine; PCho, phosphocholine; r2, coefficient of correlation of the standard curve; SD, standard deviation; S/N, signal-to-noise ratio; TMAO, trimethylamine N-oxide; Δnom.conc., difference among nominal concertation of standards.