What is pump in HPLC?
An HPLC pump is also called a “solvent delivery system.” The purpose of the pump is to maintain a constant flow of mobile phase through the HPLC system. This is accomplished regardless of the back pressure caused by the flow resistance of the HPLC column.
What is the unit of pump pressure in HPLC?
Operating pressure limits for regular HPLC systems (not UHPLC) are often in the range of 5800 – 7000 psi (400 – 500 bar), which is usually also appropriate for HPLC column hardware and (fully porous particle) packing material.
Which is the most popular pump used in HPLC?
There are two common types of HPLC pumps: reciprocating pumps and syringe pumps. Reciprocating pumps are by far the most common pump used and can have single piston or dual pistons.
Why are multiple pumps used in HPLC?
Dual-Piston Pumps have two pistons operating in parallel, fully out-of-phase with each other, to produce naturally smooth fluid flow. This is critical for many analytical chromatography applications.
What is stroke volume in HPLC?
■Stroke Volume. The default stroke is 132μL, but when the movement of the plunger (Stroke Volume) is large and the baseline fluctuates due to mixing, it can be expected that the baseline fluctuation will be reduced by setting a small stroke volume. However, if it is set small, the maximum flow rate will also be small.
Why C18 column is used in HPLC?
C18 is octyldecylsilane and contains 18 carbons bound to the silica. So they have more carbons and a longer carbon chain than C8 (8 carbons) or C4 (4 carbons). Because of the extra carbons, C18 has a larger surface area that the mobile phase has to travel across.
Why does HPLC need high pressure?
Smaller particle sizes [<10 microns] are required to improve separation power. However, smaller particles have greater resistance to flow, so higher pressures are needed to create the desired solvent flow rate.
Why is pressure important in HPLC?
Yet pressure is one of the most important parameters in successful HPLC. The role of pressure is to drive the mobile phase through the small particles packed into the chromatographic column.
How many types of HPLC pumps are there?
There are three main types of HPLC pumps.
Why do we use wet prime in HPLC?
Wet prime pumps (often called ‘self-primers’) require the casing to be filled with water prior to the first start-up only. After that, the liquid will always remain in the pump volute, so the suction hose can run dry without damaging the pump or seals.
What is void volume in HPLC?
The HPLC column void volume denoted Vm or V0 is in simple terms the volume of the mobile phase in the column. It is the part of a fraction that when added to the volume of the stationary phase makes up a whole fraction or 100% volume.
What is tailing factor in HPLC?
Symmetry factor (S, also called “tailing factor”) is a coefficient that shows the degree of peak symmetry.