66 / 116
ANTH-002
analysis or different processing methods used to
calculate both standards and samples together at
different wavelengths to ensure consistency.
Clarity required around standard concentration
calculation. The standard listed in method is salt form.
No discussion of handling/drying of standard material
covered. Results are then Cyanidin-3-chloride, or
converted to Cyanidin-3-glucoside with correction factor
of 1.38 as listed in 8.6.4. This factor is incorrect, it should
be 1.3926, molecular mass data from Chem
Spider:(Cyanidin-3-glucoside 449.384 Da; Cyanidin
chloride 322.697 Da)
No QC, acceptance criteria or performance criteria in the
method. Either a NIST or other validated control needs
to be included.
No expiration dates on solutions, standards or samples,
or storage conditions of such. The filter type used to
filter samples is not stated.
There is no discussion of light sensitivity of the analytes
and working under yellow lights or using actinic
glassware.
There is no information in regard to the ruggedness of
the method when dealing with dietary supplement
matrices.
Comparing "fingerprints" of analytes may be difficult
between different HPLC systems/conditions as well as
growing conditions/harvest times. This could be
elucidated with example chromatograms.
Supporting Data
General Comments
No example chromatograms are included, so cannot
comment on resolution of peaks of interest or the
sensitivity.
Method Optimization
Sonication of samples and/or other extraction solvents
might be explored for increased extraction efficiency of
analytes.
Performance Characteristics
Analytical Range:
18 to 180 mg/L standard curve range.