AOAC_SPDS_ERP_-_Set_3

AOAC SPDS ERP - Set 3 Review Form 2

Submission Date

2016-07-28 16:42:40

Name

Melissa Phillips

E-mail

melissa.phillips@nist.gov

Organization

NIST

Title of Method

Analysis of Theanine in Tea (Camellia sinensis) Dietary Ingredients and Supplements by High- Performance Liquid Chromatography with Post-Column Derivatization: Single Laboratory Validation

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

TEA-01

Applicable SMPR

2015.014

Summary:

This method is presented for determination of theanine in green tea containing dietary ingredients and supplements. The method utilizes simple sonication extraction in LiCitrate buffer and cation exchange chromatography with post-column ninhydrin derivatization before absorbance detection.

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

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. 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).

The method only addresses the determination of theanine. Method does not address determination of catechins, methyl xanthines, or theaflavins.

Considering only theanine: Analytical range stated in SMPR: 10-100,000 ppm. Lowest calibration level in method was 0.5 ug/mL or ~500 ppm. Lowest product tested was 41 ppm. Method states to use 0.1 to 1.0 g portions of sample (does this cover the range of samples concentrations specified in the SMPR?). LOQ stated in SMPR: <5 ppm. LOQ calculated in method: 3 ppm. Recovery stated in SMPR was met for all conditions (considering only total recovery). If marginal recovery is considered, method is outside spec for liquid product (109% at 575 ppm). 80-110% for 10-50 ppm 90-107% for 51- 500 ppm 95-105% for 501-10,000 ppm RSDr stated in SMPR was met for all conditions. <7% for 10-50 ppm <5% for 51-10,000 ppm Tested products include powders, liquids, tablets, capsules, softgels, and gelcaps. Method did not address gummies or chewables.

Yes.

Yes, very clear section on safety included.