• Decomposition of the analyte at high temperatures during chromatography; this
implies that the enantiomer which spends a longer time in the column will be lost
preferentially causing an error in the enantiomeric ratios.
• Co-elution of impurities spuriously increasing peak areas; basically, this effect
has also to be observed in the course of cGC with achiral stationary phases;
however, it should be noted that the application of chiral stationary phases
doubles the number of peaks of chiral components and thus the chance of
co-elution effects.
• The racemisation of labile enantiomers causing peak distortions due to inversion
of configuration during enantiomer separation.
• Peak distortions caused by inadequate instrumentation.
• Non-linear detector response.
For a deepened discussion on these potential errors, the reader is referred to the
review paper by Vetter and Schurig (1997). Additional errors can be caused by
unsatisfactory calibration curves, overloading phenomena and possible lack of
standards of highest optical purity.
Furthermore, Meyer pointed out that the chromatographic quantitation of very
low amounts of an enantiomer in the presence of its antipode can be an extraordinary
challenge (Meyer 1989). If the resolution of the peaks is not complete even at
extreme mass ratios, an integrator will yield inaccurate results due to geometric
effects. A given resolution can be adequate for peaks of similar size, but result in
severe overlap, if one of the signals is markedly smaller. Furthermore, if tailing
occurs, the problem appears to be especially severe for the last eluted small peaks.
General, all the above-mentioned potential errors can also be applied to other
chromatographic separation techniques used for the determination of enantiomeric
signatures (Hühnerfuss and Shah 2009).
References
Ahuja S (1997) Chiral separations: applications and technology. American Chemical Society,
Washington, DC
Ahuja S (2000) Chiral separations by chromatography. Oxford University Press; American Chemical Society, Oxford, England, Washington, DC
Ali I, Aboul-Enein HY (2004) Chiral pollutants: distribution, toxicity, and analysis by chromatography and capillary electrophoresis. West Sussex, Eng.; J. Wiley, Chichester; Hoboken, NJ
Asmund G, Cleemann M (2000) Analytical methods, quality assurance and quality control used in
the Greenland AMAP programme. Sci Total Environ 245(1–3):203–219
Asmund G, Vorkamp K, Backus S, Comba M (2004) An update on analytical methods, quality
assurance and quality control used in the Greenland AMAP programme: 1999-2002. Sci Total
Environ 331(1–3):233–245
Berthod A (2010) Chiral recognition in separation methods: mechanisms and applications.
Springer, Heidelberg; New York
Chan CC (2004) Analytical method validation and instrument performance verification. John Wiley
& Sons, Hoboken, NJ
References
103
implies that the enantiomer which spends a longer time in the column will be lost
preferentially causing an error in the enantiomeric ratios.
• Co-elution of impurities spuriously increasing peak areas; basically, this effect
has also to be observed in the course of cGC with achiral stationary phases;
however, it should be noted that the application of chiral stationary phases
doubles the number of peaks of chiral components and thus the chance of
co-elution effects.
• The racemisation of labile enantiomers causing peak distortions due to inversion
of configuration during enantiomer separation.
• Peak distortions caused by inadequate instrumentation.
• Non-linear detector response.
For a deepened discussion on these potential errors, the reader is referred to the
review paper by Vetter and Schurig (1997). Additional errors can be caused by
unsatisfactory calibration curves, overloading phenomena and possible lack of
standards of highest optical purity.
Furthermore, Meyer pointed out that the chromatographic quantitation of very
low amounts of an enantiomer in the presence of its antipode can be an extraordinary
challenge (Meyer 1989). If the resolution of the peaks is not complete even at
extreme mass ratios, an integrator will yield inaccurate results due to geometric
effects. A given resolution can be adequate for peaks of similar size, but result in
severe overlap, if one of the signals is markedly smaller. Furthermore, if tailing
occurs, the problem appears to be especially severe for the last eluted small peaks.
General, all the above-mentioned potential errors can also be applied to other
chromatographic separation techniques used for the determination of enantiomeric
signatures (Hühnerfuss and Shah 2009).
References
Ahuja S (1997) Chiral separations: applications and technology. American Chemical Society,
Washington, DC
Ahuja S (2000) Chiral separations by chromatography. Oxford University Press; American Chemical Society, Oxford, England, Washington, DC
Ali I, Aboul-Enein HY (2004) Chiral pollutants: distribution, toxicity, and analysis by chromatography and capillary electrophoresis. West Sussex, Eng.; J. Wiley, Chichester; Hoboken, NJ
Asmund G, Cleemann M (2000) Analytical methods, quality assurance and quality control used in
the Greenland AMAP programme. Sci Total Environ 245(1–3):203–219
Asmund G, Vorkamp K, Backus S, Comba M (2004) An update on analytical methods, quality
assurance and quality control used in the Greenland AMAP programme: 1999-2002. Sci Total
Environ 331(1–3):233–245
Berthod A (2010) Chiral recognition in separation methods: mechanisms and applications.
Springer, Heidelberg; New York
Chan CC (2004) Analytical method validation and instrument performance verification. John Wiley
& Sons, Hoboken, NJ
References
103