Method (M)

M1

M2

M3

Gravimetry

HPLC-UV

UV-VIS-NIR

LC-MS/MS

Mean, X_i

999.93

999.65

1000.15

998.33

Combined standard Uncertainty, u_c

3

5.97

6.23

12.40

Weight of the method mean, W_i

0.11

0.03

0.03

0.01

${\displaystyle \sum W_i}$

0.17

Weighing factor, w_i

0.65

0.16

0.15

0.04

W₁X₁

111.103

W₂X₂

28.03

W₃X₃

25.77

W₄X₄

6.50

Weighted mean, y_char

999.86

$w_1^2{u}_c^2$ (Gravimetry)

9.42

$w_1^2{u}_c^2$ (HPLC)

0.95

$w_2^2{u}_c^2$ (UV-VIS-NIR)

0.88

$w_3^2{u}_c^2$ (LC-MS/MS)

0.22

${\displaystyle \sum w_i^2{u}_c^2}$

11.47

$u_{char}=\sqrt{{\displaystyle \sum w_i^2{u}_c^2}}$

3.39

σ homogeneity (σ_h)

0.79

Short-term stability (sts)

0.39

Long-term stability (lts)

2.45

k

2

U_CRM

8.54 mg/kg

U_CRM %

0.85