Table 1.
Amino Acid | Precursor ion | Product ion | Retention timea | DPb | EPb | CEb | CXPb | Linear range | r2 | LoDc | LoQc |
---|---|---|---|---|---|---|---|---|---|---|---|
(mass) | (mass) | (min ± SD) | (volts) | (volts) | (volts) | (volts) | (fmol) | (fmol) | (fmol) | ||
Lysine and derivatives | |||||||||||
Lys | 147 | 84 | 1.16 ± 0.01 | 40 | 10 | 24 | 12 | 20 – 5000 | 0.995 | 1.30 | 4.35 |
1meK | 161 | 84 | 1.27 ± 0.02 | 70 | 10 | 23 | 10 | 20 – 5000 | 0.998 | 0.56 | 1.85 |
2meK | 175 | 84 | 1.39 ± 0.07 | 70 | 10 | 25 | 10 | 20 – 5000 | 0.999 | 0.51 | 1.69 |
3meK | 189 | 84 | 1.46 ± 0.08 | 70 | 10 | 29 | 10 | 20 – 5000 | 0.999 | 0.42 | 1.41 |
Arginine and derivatives | |||||||||||
Arg | 175 | 70 | 3.27 ± 0.01 | 60 | 10 | 33 | 10 | 20 – 5000 | 0.999 | 0.20 | 0.65 |
1meR | 189 | 70 | 3.27 ± 0.01 | 50 | 10 | 31 | 8 | 20 – 5000 | 0.999 | 0.56 | 1.85 |
2meR | 203 | 70 | 3.26 ± 0.01 | 46 | 10 | 33 | 10 | 20 – 5000 | 0.999 | 0.24 | 0.80 |
Mean ± SD of eight biological replicates collected over a six-month period
DP; declustering potential; EP, entrance potential; CE, collision energy; CSP, collision cell exit potential as optimized by Analyst 1.6.1 software.
Limits of detection (LoD) and quantification (LoQ) were extrapolated from linear regression analysis as signal-to-background ratios of 3:1 and 10:1, respectively [30].