SPIFAN Nutrients ERP Book 9-29-15

Sample: NIST SRM 1849A

Matrix: Infant/adult nutritional formula.

Species

Result

n Reference value Comment

free choline ion

802 ± 21 mg/kg 4 789 mg/kg

Informative value

Sample: NIST SRM 1546

Matrix: Meat Homogenate.

Species

Result

N Reference value

Comment

choline ion

558 ± 14 mg/kg

2 580

Informative value

For both choline values on SRM 1849A (free) and SRM 1546 (total) the meas-

ured values is in good agreement with the informative values.

Measuring range:

The measuring range in this validation covers the interval: LOQ

–

1000 ng/g.

Samples containing concentration higher than the highest standard will be reana-

lysed with a more fitting sample size and/or dilution leading to a concentration in-

side the standard range.

Limit of detection / quantification:

LOD has been determined by treating a standard at low level (9 ng/g) as a sam-

ple, the reason this approach has been used is that it has been impossible to find

a natural sample containing choline at a level near the expected limit of detection.

The sample was analysed as a 10 replicates measurement on the same day, the

standard deviation (S

) has been calculated from these results. See appendix 3.

LOD is calculated as 3 x S

and LOQ as (10 x S

The limit of detection and quantification for choline is calculated to:

LOD: 2,2 ng/g

LOQ: 7,3 ng/g

LOQ in samples as mg/kg is calculated from an aliquot of 20 g sample (maxi-

mum) extracted into 110 g extraction solution. 10 g extraction solution is diluted to

250 g, (this sums up to a total dilution factor of 137,5).

Choline in samples:

LOQ: 1,0 mg/kg

Carn-06 (Choline Validation Report)

FOR ERP USE ONLY

DO NOT DISTRIBUTE