Table 4 Method validation parameters for five reference analytes

Regression equation

6.01× + 0.33

5.53× + 0.31

40.02× + 0.05

41.44× + 0.02

306× + 1.92

Correlation coefficient (r²)

0.9998

0.9999

0.9995

1.0000

0.9996

Linearity range (ng/mL)

1–250

1–250

0.5–100

0.1–100

5–500

LOD (ng/mL)

0.14

0.20

0.03

0.01

0.02

LOQ (ng/mL)

0.43

0.61

0.09

0.03

0.07

Precision RSD % (Intra-day, n = 6)

0.34

1.02

0.62

0.25

0.61

Precision RSD % (Inter-day, n = 6)

1.01

1.22

1.11

0.94

1.21

Stability RSD % (n = 5)

1.83

2.55

1.88

1.92

1.80

Recovery (n = 3) Mean

105.19

97.50

94.87

95.50

98.86

RSD %

0.76

1.02

1.13

1.82

0.96