Hints For Using The Fast Composition Change/Reconditioning; Purpose - Agilent Technologies 1200 Series User Manual

3 Becoming an expert

Hints for Using the Fast Composition Change/Reconditioning

Fast composition/reconditioning function can not be used for nanospray with MS. If the
N O T E
flow stops and the needle is not removed from the near-by heated electrode, the needle will
plug. Fast composition can not be used between runs because it eliminates the liquid flow
to the nanospray tip, which will get plugged or damaged by the counter electrode plate.

Purpose

The nano pump and the micro well plate sampler are recommended for nano
LC applications. Nano LC methods have very low column flow rates, typically
around 300 nl/min. At such low flow rates, re-equilibrating the column with a
new composition in direct injection mode takes a long time. Therefore it is
useful in method development when the autosampler is in mainpass and a
new composition is set, to use the fast composition mode and flush the micro
well plate sampler loop at high flow rates. The new composition will reach the
column much faster.
The Fast Composition Change/Reconditioning function is available only in a
system that includes both a nano pump and a micro well plate sampler. This
function can be set up to occur automatically between runs, and/or to occur
automatically after any manual composition change. Primary Flow is a
parameter which exists only when the nano pump is used in the Micro mode.
Primary flow is defined as the flow volume and composition available at the
inlet to the EMPV. Using this available primary flow, the EMPV and flow
sensor work together to deliver and control the requested column flow. All
primary flow in excess of the column flow is delivered to waste via the 1/8
inch plastic waste tube connected to the EMPV barbed waste fitting.
The Fast Composition Change/Reconditioning function is available only when the nano
N O T E
pump is operated in the micro mode.
38 1200 Series Nano Pump User Manual