AOAC SPDS Meeting Book March 19 2015

3/11/2015

Method performance requirements

Gallic acid equivalent (w/w)

A l ti l

na y ca range

5 500

– ppm

Limit of Quantitation (LOQ)

≤ 5 ppm

Recovery, %

80 – 110

5 – 30 ppm

≤ 12

Repeatability, %

>30 – 100 ppm

≤ 10

>100 – 500 ppm

≤ 8

Reproducibility, %

5 – 30 ppm

≤ 7

Comments Submitted (if any)

• The reference NIST materials recommended was not certified for total  phenolics, so not sure how these NIST materials are appropriate to list.   Possibly include a sample purification step to remove interfering  d th th h li th FC t t ith f b tt compoun s o er an p eno cs e  reagen reac s w or e er  total phenolic value. 

• The SMPR has been revised to Estimate of Phenolic Content using  Folin‐C which is determined in the SRM.

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