ABSTRACT
LC separation is to bring about the physical separation
of sample constituents; however, as the sample complexity
increases this becomes more difficult. Hyphenation and the
application of selective detection, for example, can estab-
lish the separation of species according to information, but
not necessarily in a physical sense. A DAD may be tuned
to a particular wavelength such that the desired species are
visible but the undesired species are not, or an MS can be
tuned to respond to a particular mass ion. So, if the phy-
sical collection of sample constituents is a requirement
of the separation process, attention must be paid to the
chromatography. Furthermore, some hyphenated methods
of analysis are best served when good chromatography is
applied, such as LC-NMR methods, whereby the interpre-
tation of the NMR information is made easier as the purity
of the sample constituent is improved.
