AOAC OMA# 2011.06 Final Action Review-OMB

2011.06 (September 2017)-Fol-22 MLT Report

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HorRat R (Limit 2.0)

1.06

1.20

0.88

0.79

0.74 0.68

0.72 0.70 0.76

0.66

0.80

HorRat R

0.62

0.61

0.40

0.00

Sample Name

Figure 14: Folate Horwitz Ratio for the SPIFAN samples (HorRat R )

5. METHOD ACCURACY:

The results obtained in the current MLT study for the NIST SRM 1869a for folic acid are used to evaluate accuracy of the method. Folic acid results of the MLT study for NIST SRM 1869a are compared with the NIST consensus value which has been documented by the NIST for this reference material (Table 6). They were kind enough to share those values with us. The NIST has folic acid consensus value for this SRM based on participation from17 laboratories. The total folate level in this NIST SRM has not been Certified by the NIST yet for this SRM. The grand mean value obtained by the MLT study was close to the NIST mean and the value was within the NIST range. Table 6: Accuracy results for folic acid in NIST SRM 1869a Parameters Symbol SRM 1869a PTLO721/ GBZC169 Total number of laboratories p 11 Total number of replicates Sum(n(L)) 33 Overall mean of all data (grand mean) (mcg/100g) XBARBAR 209.8 Repeatability standard deviation s(r) 13.9 Reproducibility standard deviation s(R) 23.8 Repeatability relative standard deviation RSD r 6.6 Reproducibility relative standard deviation RSD R 11.3 HORRAT value HorRat R 0.79 NIST Consensus Mean (mcg/100g) NIST Mean 215.0 NIST Range (mcg/100g) NIST Range 159 - 240

Collaborative Study Report: Method AOAC 2011.06 (Folate by LC-MS/MS) 19