2015.14 Vitamin B (July 2018)

2015.14 (JULY 2018) BVit‐02 Total Bs ERP Evaluation Form

FOR ERP USE ONLY DO NOT DISTRIBUTE

Accuracy ‐ Analytical bias compared to reference material Certified Reference Material

Table 2

Measured Results

T stat Bias

Confidence interval 

CRM product

Analyte

Certified value Uncertainty Certified range Concentration Difference from  certified value

p ‐value

Nominal

131.7 134.1 129.9 130.5 129.7 126.2 143.3 144.3 130.4 129.3 129.5 128.6 132.3

2.9 0.5 4.7 4.1 4.9 8.4 4.2 5.3 5.1 6.0 2.3 5.7 ‐8.7 ‐9.7

SRM 1849a

Pyridoxine (ug/100g)

134.6

9.3

125.3 ‐ 143.9

‐2.3

1.406

0.187

128.7 ‐ 135.9

Mean   

SD   

5.7

d

T stat =

/ sd

n

where:       = mean of the differences between measured results and reference value sd  = standard deviation of the differences between results and reference value n   =  number of replicate analyses of SRM d

H 0 :       = 0,   The null hypothesis is that there is no difference between the measured results and the certified value:

d

p ‐value: is the probability (at the 95% levels of confidence) of obtaining the test statistic assuming that the null hypothesis is true p ‐value < 0.05 indicate a difference of statistical signifance between measured results and SRM.

95% confidence interval: The true population of the measured value expected to fall within the confidence interval estimate 95% of the time

sd

sd

t crit

t crit

lower limit  = mean ‐

upper limit = mean +

n

n

crit t

where:           =  critical values of the t‐distribution

sd  = standard deviation of the differences between results an reference value n   =  number of replicate analyses of SRM