Carn-06_Book_Final

Carn-06 (Choline Validation Report) FOR ERP USE ONLY DO NOT DISTRIBUTE

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 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. 558 ± 14 mg/kg 2 580

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 r ) has been calculated from these results. See appendix 3. LOD is calculated as 3 x S r and LOQ as (10 x S r ). 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