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Submission Date
2016-07-29 17:50:23
Name
Melissa Phillips
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.
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.
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.
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.
Yes
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).
No safety information included. Might be necessary for working with concentrated acids
in diluent preparation.
AOAC SPDS ERP - Set 3 Review Form 2