YL Instruments YL9100 HPLC, User Manual

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YL9110 Quaternary Pump
4-2. Mobile phase filter and bottle
Solvent vessel should be positioned at higher location than pump and not be positioned below pump,
and inlet tubing length should be as short as possible. This can minimize pressure drop caused at inlet of
pump during suction.
When using solvent having high vapor pressure as hexane, formation of air bubble is caused due to
large pressure drop in suction part in high flow rate; so particular care should be taken, and mobile phase
should be maintained after air separation, filtration and air-tightening.
Mobile phase filter of 10
μ
m porosity is connected into inlet tubing in order to prevent entering of small
particles. Mobile phase filter is blocked if mobile phase is bad or is used for long time, it is necessary to
clean or change filter in this case.
4-3. Preparation of solvent
Proper solvent prevents various problems happened during actual analysis.
Solvent gas removal and filtration are necessary because they have great effect on result of analysis and
maintenance of instrument.
4-3-1.Degassing
Solvent gas removal is performed in order to remove gas such as nitrogen or oxygen contained in
mobile phase. Contained gas should be removed by air separation before mobile phase is used or while
mobile phase is used, and the most practical technology for air separation is to insert helium into solvent.
Helium is easily separated from HPLC solvent, so other gases contained in solvent may be easily
removed due to diffusion of helium gas.
When mixing organic solvent such as methanol or acetonitrile into water, this mixture contains very
small quantity of gas as compared to the quantity of pure composition; so it has more strong tendency to
discharge gas. Back pressure regulator attached to outlet of detector prevents formation of noise in base
line due to air bubble, and mobile phase vessel should be pressurized under 2-3psi pressure with helium if
it is desired to reduce gas discharge due to solvent mixing.
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