SPDS Lutein and Turmeric ERPs

44 / 154

Reviewer Name: Hong You
Email:
Organization:
Method Reviewed: LUT‐02
Method Title: Determination of Lutein and Zeaxanthin Esters and Their Geometric Isomers in
Carotenoid Ester Concentrates Used as Ingredients in Nutritional Supplements:
Validation of a Combined Spectrophotometric‐HPLC Method
Applicable SMPR 2016.004
Summary of Method: The combined spectrophotometric‐LC method was published in August 2016 at J
AOAC and submitted to the ERP for SPDS Set 4 Ingredients in response to the call for
methods. A three‐step procedure is used, involving (1) an HPLC chromatogram of the
saponified sample to calculate the composite‐specific absorbance value based on its
carotenoid profile and documented or estimated extinction coefficients (1%) of
predominant geometrical isomers of lutein and zeaxanthin esters, (2) measurement
of the optical absorbance of the unsaponified sample and calculation of its specific
absorbance at 445 nm, and (3) calculation of the total carotenoid ester content of
the sample. No calibration standards are needed for this protocol.
1. Does the Applicability of the
Method Support the Applicability
of the SMPR? If not, please explain
what is missing.
This method is able to separately determine the fatty acid esters of the cis and trans
isomers of lutein and zeaxanthin in ingredients and dietary supplements. However, it
cannot distinguish the esterified and nonesterified forms of these xanthophylls. In
addition, this method did not document any information about beta‐cryptoxanthin.
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.
Yes, the analytical techniques used in the method meet the SMPR requirements.
3. Are the definitions specified in
the SMPR used and applied
appropriatly in the method? If no,
please indicate how the terms are
used.
Authors used “Precision” as the term to document both “Repeatability” and
“Reproducibility” procedures. Authors established “Recovery” by comparing the
analytical results of commercial samples with values from suppliers’ Certificate of
Analysis, while the SMPR requires comparing the analytical results from spiked
sample with their theoretical value.
4. Does the method, as written,
contain all appropriate precautions
and warnings related to the
method's regaents, components,
instrumentation, or method steps
that may be hazardous? If no,
please suggest wording or
option(s).
Method's reagents, components, instrumentation, or method steps are generally
safe.
1. Are the definitions specified in
the SMPR used and applied
appropriately in the supporting
documentation (manuscripts,
method studies, etc…)? If not,
please explain the differences and
if the method is impacted by the
difference.
Yes.
General Information
I. Summary
II. Review of the Method Only
III. Review of Information in Support of the Method