Background Image
Table of Contents Table of Contents
Previous Page  540-541 / 620 Next Page
Information
Show Menu
Previous Page 540-541 / 620 Next Page
Page Background

Table 2

Nominal

T

stat

p

-value

131.7

2.9

134.1

0.5

129.9

4.7

130.5

4.1

129.7

4.9

126.2

8.4

143.3

-8.7

144.3

-9.7

130.4

4.2

129.3

5.3

129.5

5.1

128.6

6.0

Mean

132.3

2.3

SD

5.7

5.7

T

stat

=

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

H

0

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

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.

lower limit = mean -

upper limit = mean +

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

Accuracy - Analytical bias compared to reference material

Certified Reference Material

Measured Results

CRM product

Analyte

Certified value Uncertainty Certified range Concentration

Difference from

certified value

SRM 1849a

Pyridoxine (ug/100g)

134.6

9.3

125.3 - 143.9

128.7 - 135.9

Bias

Confidence interval

-2.3

1.406

0.187

n

/

sd

d

d

d

n

t

crit

sd

n

t

crit

sd

crit

t

SPIFAN ERP Checklist v1.0

BVit-02 - MEF FORM

FOR ERP USE ONLY

DO NOT DISTRIBUTE