Table 3 The overview of analytical performance of Tg-iMRM-MS established in Taiwan

1. Assay development

 Transition selection

Target and internal standard peptides

FSP2 (704.04/586.90, 704.04/687.5), FSP4 (709.04/591.89, 709/04/697.5)

 Collision energy optimization

Default ± 10

y7: 33.2; y12: 38.2

2. Reportable range

 Calibration curve

Standard serum or pooled clinical serum, serial dilution

0.2 ~ 13 ng/mL

 LOD

Lowest detectable concentration

0.1 ng/mL

 LOQ

Lowest quantifiable concentration, CV < 20%

0.2 ng/mL

3. Accuracy

Evaluated by QC samples, deviation < 20%

QC_mid: 7.8%; QC_high: 8%

4. Precision

Evaluated by QC samples, deviation < 20%

 Within-day repeatability

2 or 3 QC samples, 4 replicates/day, 3 ~ 5 days

QC_low: 10.07%; QC_mid: 7.52%; QC_high: 5.49%

 Between-day reproducibility

2 or 3 QC samples, 1 replicate/day, 7 ~ 10 days

QC_low: 9.82%; QC_mid: 7.97%; QC_high: 9.92%

5. Sensitivity

LOQ

0.2 ng/mL

6. Specificity

Signal overlay of endogenous and internal standard peptides

7. Interference

Hemolysis, deviation < 20%

< 25% hemolysis (62.5–125 mg/dL) is tolerated

8. Stability

Room temperature (20 °C); 4 °C; -80 °C

RT: 48 h; 4 °C: 48 h; -80 °C: > 1yr

9. Proficiency test

20–35 QCs and clinical samples exchanged

with reference laboratory

r² = 0.996, slope = 0.9287