SPIFAN Nutrients ERP Book_9-29-15

BVit-02 - MEF FORM FOR ERP USE ONLY DO NOT DISTRIBUTE

Table 2

Accuracy - Analytical bias compared to reference material Certified Reference Material

Measured Results

T stat Bias

Difference from certified value

CRM product

Analyte

Certified value Uncertainty Certified range Concentration

Confidence interval

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

2.9 0.5 4.7 4.1 4.9 8.4

SRM 1849a

Pyridoxine (ug/100g)

134.6

9.3

125.3 - 143.9

-2.3

1.406

0.187

128.7 - 135.9

-8.7 -9.7

4.2 5.3 5.1 6.0

Mean

132.3

2.3

SD

5.7

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

t

where: = critical values of the t-distribution

crit

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

SPIFAN ERP Checklist v1.0