26 / 116
CHON-002
• Extraction was assumed to be finished upon complete
disintegration of the tablet in water. Data was not presented
for determination of complete disintegration.
• Samples were filtered using unspecified filter paper. Filter
recovery studies were not reported.
• pH is critical for the success of this type of analysis. Data
was not given for leading or terminating solutions at various
pH levels.
• Authors used enzymes for the digestion of CS. The
chondroitinase is pH, concentration and temperature
dependent. The authors did not describe the sample
preparation in the original paper. They did however, discuss
following the procedure published by Volpi in 2007 with some
modifications. It’s not clear if these modifications were
consistent.
Method Clarity
Miscellaneous typos, cation vs anion among others. The
method lacks details for step by step sample preparation used
for analysis. This could be due to the 10-page limitation for
articles to be included in this particular journal. Sample
preparation dilution on p. 59 appears to be out of the
calibration curve but in Table 3 the validation samples were
stated to be diluted into the calibration curve range. It’s
unclear if this was done with routine samples as well. Sample
filtration was performed with an unspecified filter type. Filter
studies not mentioned. Method was used to test multiple
dosage forms but the validation was only for tablets. There is
no suggested system suitability requirements. The method
refers to analysis of CS but sample concentration estimation
appears to be based on CS-A during the validation. It’s unclear
which reference material are used in the preparation of stock
and working standards, page 59 P2.
Pros/Strengths
No dangerous chemicals required
Simple sample preparation in water
Short analysis time
Cons/Weaknesses
In general, CE has some drawbacks:
• Low sensitivity
• Sample concentrations must be dramatically increased to
obtain the same S/N compared to a typical LC run
• pH in the capillary can be affected resulting in countering of
the stacking effect.
• Lack of data regarding standard retention times and peak
area
o Inability to quantify analyte
o Irreproducible flow rates
o Inconsistent injection volumes