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

CRM product

Analyte

Certified value Uncertainty Certified range Concentration Difference from  certified value

Confidence interval 

p ‐value

Nominal

125.6 128.5 128.7 128.8 130.3 130.0 131.2 136.4 122.5 122.4 127.4 130.2 128.5

0.1

‐2.8 ‐3.0 ‐3.1 ‐4.6 ‐4.3 ‐5.5

SRM 1849a

Thiamin (ug/100g)

125.7

9.8

115.9 ‐ 135.5

2.8

2.545

0.027

126.1

‐ 130.9

‐10.7

3.2 3.3

‐1.7 ‐4.5 ‐2.8

Mean   

SD   

3.8

3.8

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