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Fonterra Co-operative Group
Page 6
lower and upper limits of the range specified in the vitamin D SMPR [2]. The average range for vitamin D
3
in
linearity standards was 0.5
–
92.8 ng mL
-1
, which is equivalent to a sample concentration of 0.6
–
102 μg hg
-1
(0.06
–
11.3 μg hg
-1
RTF) which exceeds both the lower and upper limits of the range specified in the
vitamin D SMPR [2].
Table 2: Variance of vitamin D
2
back-calculated concentrations
Standard Number
Variance
(1)
(%)
Experiment 1
Experiment 2
Experiment 3
1
-29.0
-30.1
-34.4
2
-0.7
-8.5
-5.8
3
-0.9
-0.4
-1.8
4
1.0
1.3
0.6
5
0.3
0.6
1.7
6
-0.2
-0.3
-0.7
(1)
Variance of back-calculated concentration from regression against actual concentrations
Figure 1: Linearity and residuals plots for vitamin D
2
linearity experiment 1
Figure 2: Linearity and residuals plots for vitamin D
2
linearity experiment 2
y = 0.8987x + 0.0105
R² = 1
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0.0
2.0
4.0
6.0
8.0
Peak Area Ratio
Concentration Ratio
Linearity: Vitamin D
2
28
th
Dec 2015
-0.1
-0.05
0
0.05
0.1
0.0
2.0
4.0
6.0
8.0
Residuals
XVariable
Residual Plot: Vitamin D
2
28
th
Dec
2015
y = 0.8609x + 0.0117
R² = 0.9999
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0.0
2.0
4.0
6.0
8.0
Peak Area Ratio
Concentration Ratio
Linearity: Vitamin D
2
29
th
Dec 2015
-0.1
-0.05
0
0.05
0.1
0.0
2.0
4.0
6.0
8.0
Residuals
XVariable
Residual Plot: Vitamin D
2
29
th
Dec
2015
VitD-18 (February 2016)
FOR ERP USE ONLY
DO NOT DISTRIBUTE