A. Kunkel et al., QUANTITATION OF INSULIN BY CAPILLARY ELECTROPHORESIS AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - METHOD COMPARISON AND VALIDATION, Journal of chromatography, 781(1-2), 1997, pp. 445-455
Citations number
33
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Two validated high-performance liquid chromatography (HPLC) and capill
ary electrophoresis (CE) assays for insulin are compared. Both methods
are selective and robust, with best reproducibility in a 0.9% sodium
chloride solution, pH 7-8, as the sample solvent, It is shown that, be
sides sample solvent and buffer pH, acetonitrile volatility is a cruci
al point for reproducibility. Its high importance for selectivity and
ruggedness is also stressed. Trends have been extensively investigated
and characterized. The separation efficiency is better for the CE met
hod. Furthermore, the analysis time of the CE method is up to four tim
es shorter than the respective parameter in HPLC and the acetonitrile
consumption is more than 100-fold less, Earlier works stated that all
relevant precision data, such as relative signal standard deviation (1
.6% R.S.D. for peak areas, n = 20), precision of the analytical result
and the limit of quantitation, were about a factor of two worse than
for corresponding HPLC data (0.8% R.S.D. for peak areas, n = 19). This
CE precision was further improved using relative instead of absolute
peak areas, which compensate for the injection error (1.3% R.S.D. for
relative peak areas, n = 20). If acetonitrile evaporation is avoided,
by covering the buffer with mineral oil, reproducibility is even bette
r than with the HPLC assay (0.5% R.S.D. for relative peak areas, n = 6
0). (C) 1997 Elsevier Science B.V.