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CHON-002
• Difficult to determine appropriate test conditions for
unknown samples.
HPLCs/UPLCs are common instruments in many labs. CE is not
as widely used.
Method specific drawbacks:
• The method is non-specific. CS-A, B, and C had almost
identical mobilities, Figure 3, p 61; therefore could not be
separated using cITP.
• The method is not able to differentiate CS-B (dermatan
sulfate).
• Acesulfam K and a high content of hydrolyzed collagen were
reported interferences. The author state that Acesulfam K was
easily detected in the UV trace at 254 nm.
• Carrageenan and Hyaluronic could cause interference with
this type of methodology.
• Author stated the presence of hyaluronate and heparin did
not disturb the analysis of CS but they did not provide any
data. The assumption was that hyaluronate has a lower
mobility than the terminator (citrate) and the heparin has a
higher mobility.
• In order to maximized separation multiple pH requirements
are required for interfering compounds.
Supporting Data
General Comments
o Sample preparation for the validation was one tablet
dissolved in 250mL MilliQ water. One tablet, or capsule, or
daily dose was used to prepare the test samples. However,
the validation used a composite of 20 tablets for homogeneity
reasons. There is no validation data for other dosage forms.
o For the validation, external calibration solutions of CS-A
were prepared at 20 – 200 mg/L to create a calibration curve
using step length vs. concentration. It is unclear there was
other work performed for total CS.
Method Optimization
The authors provided supplemental information: Quality
Control of Chondroitin Sulphate used in Dietary Supplements.
Czech Journal of Food Science 33:165-173. Modifications to
the method were pH and the leading electrolyte composition.
The scope of method was for raw material. Reference
standards were EP CRS grade.
cITP was used to determine the free sulphate content in CS.
This method is unable to differentiate CS-B (dermatan
sulphate)