Waters ACQUITY UPLC M-Class - Dispersion; Carryover

Waters column packed with sub-2-micron particles provides sufficient back pressure to retard
outgassing. If outgassing occurs, Waters recommends using the optional solvent stabilization kit.
• Do not submerge the waste or degasser vent lines in liquid.
See also: The µBinary Solvent Manager Overview and Maintenance Guide for details on how to
route waste and degasser tubing.
• Flush buffers from the system using water immediately after you are done with them.
• Use 10% to 20% organic solvent in water as a storage solvent if you keep the system idle for
extended periods (longer than 24 hours).
• If the system is idle for a day or two, keep the system running rather than shutting it down.
• For best performance, configure eluent compositions with at least 3% A or B. Lesser
contributions from either the A or B eluent may result in decreased retention time
reproducibility.
• Monitor the waste level to ensure that it is never too high.
• When starting the µBSM, ensure that solvent flows through pump A and pump B. Do not
specify a 0.0 mL/min flow rate at start-up for either pump.
• Use the Load Ahead function when you want a shorter cycle time.
• If you experience problems with carryover, do not use the Load Ahead or Loop Offline
functions while you troubleshoot.
• Use of the advanced sample introduction features requires extensive knowledge of the
sample.
Notice: To prevent injury, always remove the solvent bottles when moving the micro
cart or instrument modules, or when adding or changing reagents.
2.3 Dispersion
Microscale systems require low dispersion for optimum performance. This is achieved by using
small-particle chromatography.
Small-particle chromatography relies on the use of small, high-efficiency columns. A typical 75
µm × 250 mm UPLC column has an approximate 1-µL volume, compared with 40-µL for a typical
4.6 × 150 mm UPLC column. The smaller column requires a system with low dispersion that
reduces dilution and band broadening, maintaining the symmetrical peak shape, height, and
sensitivity produced by the high-efficiency column.
2.4
Carryover
You observe carryover in chromatographic systems when a previously injected analyte appears
as a peak in the chromatogram of subsequent samples. Carryover tends to occur when a small
November 26, 2019, 715003588 Revision C
Page 26