Table V. Relative residual error and Precision in Stable-isotope Dilution (SID) and Reverse-Polynomial Dilution (RPD) calibration methods. The p-Value refers to the difference in error and precision for each individual peptide measured by the respective calibration methods. The p values for error and precision in the Mean row refers to the comparison of error and precision between calibration methods for all the peptides combined. Italics denotes the result was significantly different from SID by pairwise comparison. Relative residual error was significantly lower in phospholipid-depleted RPD (p = 0.006) and non-depleted plasma (p = 0.016) compared to SID. Relative residual error was not significantly different between phospholipid-depleted RPD and non-depleted RPD compared (p = 0.795).
| Peptide | SID |
Phospholipid-depleted RPD |
RPD |
p-Value |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Range of Quantitation (fmol) | r2 | Relative residual error (%) | Precision (CV%) | Range of Quantitation (fmol) | r2 | Relative residual error (%) | Precision (CV%) | Range of Quantitation (fmol) | r2 | Relative residual error (%) | Precision (CV%) | Relative residual error (%) | Precision (CV%) | |
| HHGPTITAKPTITAK | 5–100 | 0.992 | 13.05 | 7.39 | 5–100 | 0.999 | 4.00 | 15.36 | 5–100 | 0.999 | 4.20 | 9.00 | 0.12 | 0.99 |
| NLPSDSQDLGQHGLEED | 5–100 | 0.994 | 6.55 | 7.64 | 1–100 | 0.998 | 2.89 | 11.20 | 1–100 | 0.998 | 2.34 | 11.20 | 0.08 | 0.80 |
| VNSQSLSPYLFR | 5–100 | 0.996 | 8.20 | 17.67 | 0.5–100 | 0.997 | 2.15 | 5.50 | 0.5–100 | 0.997 | 4.37 | 7.43 | 0.22 | 0.71 |
| VSAQQVQGVHAR | 25–100 | 0.996 | 16.80 | 14.84 | 0.5–100 | 0.996 | 2.01 | 17.44 | 0.5–100 | 0.996 | 5.39 | 11.89 | 0.06 | 0.34 |
| Mean | – | – | 11.15 (±4.67) | 11.89 (±5.18) | – | – | 2.76 (±1.27) | 12.38 (±5.27) | – | – | 4.08 (±1.27) | 9.88 (±2.05) | <0.01 | 0.71 |