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Silliker
Chem, Res. Center Crete, IL – Report of A Validation of LC-MS/MS Method for Folate Analysis
29
The results of the analysis of folate and folate vitamers by the method are indicative of the accuracy of
the method.
The Precision of the Reference material analysis:
The inter-day precision of the reference material analysis of the method for folate and vitamer analysis
was found to be satisfactory and in terms of % RSD ranged between 1.6 to 12.5%.
The analysis of various reference materials over a period of about 3 months also provided a satisfactory
accuracy and precision of the method. The Folic acid results obtained for the NIST SRM 1849a by the
method over a period of about 3 months are presented in Table 25.
The accuracy and interday as well as intraday precision of the method over a period of about 3 months
was found to be satisfactory.
Table 19: Folic Acid analysis in NIST SRM 1849a (Milk based Infant Formula) over a period of
about 3 months
Folic
Acid
Results
08/28/12 09/11/12 09/14/12 09/18/12 9/21/12 09/26/12 09/28/12 10/02/12 10/12/12 10/19/12
mcg/g
Mean
2.306
2.145
2.460
2.065
2.288
2.301
2.390
2.349
2.268
2.404
%RSD
7.8%
2.9%
4.2%
1.9%
4.2%
0.4%
1.4%
5.0%
4.9%
2.3%
N =
3
3
3
3
3
3
3
3
3
3
Folic
Acid
Results
10/26/12 11/02/12 11/07/12 11/13/12 11/17/12 11/26/12 11/29/12 Grand
Grand
SD
mcg/g
Mean
2.337
2.641
2.170
2.147
2.123
2.241
2.277
2.282
0.151
%RSD
1.7%
5.8%
3.5%
6.2%
2.4%
0.5%
5.5%
6.6
N =
3
2
3
3
3
3
3
50
50
NIST
Value
2.293 + 0.062
Micro
Results
2.31*
*Result for total folate in sample as folic acid (based on a single analysis)
5-methyl-THFresults obtained for the NIST SRM 1849a by the method over a period of about 3
months are presented in Table 26. The comparison of the results obtained vs NIST specified value has
already been discussed earlier. The NIST values reported are about half of obtained by the method.
Reliability of the NIST values is in doubt as those are based on NIST in house method and not
confirmed by any other lab and likely the methodology used may be older and may lack some features
like use of internal std. as the compounds were not available till recently. Interday as well as intraday
precision of the method over a period of about 3 months was found to be satisfactory.
2011.06 (Fol-22) w/SLV
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