AOAC_SPDS_ERP_-_Set_3

AOAC SPDS ERP - Set 3 Review Form 2

Submission Date

2016-07-29 17:50:23

Name

Melissa Phillips

E-mail

melissa.phillips@nist.gov

Organization

NIST

Title of Method

Determination of Catechins and Caffeine in Camillia sinensis Raw Materials, Extracts, and Dietary Supplements by HPLC-UV: Single Laboratory Validation

AOAC Candidate Method Number (e.g. ALN-01)

TEA-02

Applicable SMPR

2015.014

Summary:

This method is presented for determination of seven catechins and caffeine in green tea containing dietary ingredients and supplements. The method utilizes simple sonication extraction in acidic solution containing EDTA and reversed-phase chromatography with absorbance detection.

Tested products include powders and tablets. Method did not address softgels, gelcaps, gummies, chewables, or liquids.

1. Does the applicability of the method support the applicability of the SMPR? If not, please explain what is missing. 2. Does the analytical technique(s) used in the method meet the SMPR? If not, please specify how it differs from what is stated in the SMPR.

The method addresses the determination of seven of the eight catechins listed in the SMPR (all but catechin gallate), as well as caffeine. The method also does not address the determination of additional methyl xanthines (theophylline and theobromine), theaflavins, or theanine.

Analytical range stated in SMPR: 10-500,000 ppm. The calibration range described in method was 1-100 ppm. Lowest level tested in any product 1260 ppm (catechin in SRM 3254). Sample preparation steps need to be modified to cover the range of samples concentrations specified in the SMPR. LOQ stated in SMPR: <5 ppm. LOQ not reported in method. Recovery was tested by spiking different quantities of SRM 3255 Green Tea Extract onto a blank multivitamin matrix. Recovery was not tested at levels below 390 ppm. Recoveries were out of spec for 7 of 8 compounds at low and middle spike levels and for 3 of 8 compounds at high spike levels. 95-105% for 501- 500,000 ppm RSDr was not reported below 1000 ppm. stated in SMPR was met for all conditions. RSDr was met for only 3 of 8 compounds and for total catechins. <5% for 51-500,000 ppm Tested products include powders and tablets. Method did not address softgels, gelcaps, gummies, chewables, or liquids.

3. Are the definitions specified in the SMPR used and applied appropriately in the method? If no, please indicate how the terms are used. 4. Does the method, as written, contain all appropriate precautions and warnings related to the method's reagents, components, instrumentation, or method steps that may be hazardous? If no, please suggest wording or option(s).

Yes

No safety information included. Might be necessary for working with concentrated acids in diluent preparation.