| 
      
        | Quality    control samples | Concentration    added (ng/ml) | Concentration    found(ng/ml) (mean ± S.D) | Precision    (%) CV | Accuracy    (%) |  
        | LLOQ    QC | 0.109 | 0.110 ± 0.005 | 4.50 | 100.91 |  
        | LQC | 0.284 | 0.270 ± 0.014 | 5.19 | 95.18 |  
        | MQC | 37.809 | 36.013 ± 0.308 | 0.85 | 95.24 |  
        | HQC | 75.619 | 72.361 ± 0.532 | 0.73 | 95.7 |  |