Waters ACQUITY UPLC I-Class, System Manual, Page: 14 / 68

1-2 ACQUITY UPLC I-Class System
UltraPerformance Liquid Chromatography
In 2004, Waters made significant advances in instrumentation and column
design when it introduced UPLC
®
technology to the field of separation science.
By employing this technology, Waters’ ACQUITY UPLC systems achieve a
marked increase in resolution, speed, and sensitivity in liquid
chromatography, when compared to conventional systems.
UltraPerformance liquid chromatography uses columns packed with round
particles, 1.7
μ
m-diameter; its operating pressures are as high as 18,000 psi.
The van Deemter equation, an empirical formula that describes the
relationship between linear velocity and column efficiency, considers particle
size as one of the variables. Thus the equation can be used to characterize
theoretical performance across a range of particle sizes.
History of particle size in liquid chromatography:
It is apparent from the figure, above, that using 1.7-
μ
m particles achieves
higher efficiency that persists as the flow rate increases (lower HETP
indicates higher efficiency, HETP = Height Equivalent to a Theoretical Plate).
When operating in this area of the plot, the peak capacity and the speed of a
separation can set limits well beyond those of conventional HPLC technology.