An HPLC quote names a pump, an injector, a column oven and a detector, and a laboratory that buys exactly that discovers over the following months how much else the method needed. This page is the list: what comes with the instrument, what has to be bought beside it, what the running cost is made of, and which of those decisions is hard to reverse later. It is written for the person signing the order rather than the person who will run the first sample.
What the instrument is, and what sits beside it
The modules on the quote are the pump, the autosampler or injector, the column compartment and one or more detectors, joined by a data system. Beside them a working bench needs solvent handling and filtration, degassing if the pump does not do it, a waste arrangement that is vented and labelled, the column and its guard, fittings and tubing in the right internal diameter, vials and closures matched to the autosampler, and standards and reference material for the method. None of that is optional and most of it is not on the quote, which is why the first year's consumable spend surprises people who compared instruments on the module list alone.
The decisions that are hard to reverse
Three choices bind you for the life of the system. The pressure class decides which columns and particle sizes you can ever use, and moving up later means a new pump rather than a new column. The detector set decides which methods transfer in and out, and adding mass detection later constrains the mobile phase you were happy with. The data system decides how your records are kept and who can read them, and in a regulated laboratory it decides your audit trail. Everything else on an HPLC bench can be swapped in an afternoon; those three cannot.
Where the running cost actually sits
Solvent, columns and the person are the running cost, roughly in that order, and the instrument's purchase price is a minority of five years. Solvent grade is part of the method rather than a procurement choice, so it cannot be traded down without revalidating. Columns are consumed at a rate set by how well the samples are prepared and whether a guard column is used. The person is the largest line and the easiest to forget when a quote is compared against a service contract.
Buying used, and what to check first
HPLC modules have a long life and a real second-hand market, and the sensible purchase is a module rather than a bargain system of unknown history. Ask for a recent qualification report, run a performance check on arrival with your own standard, and price the service contract before agreeing the purchase, because an unsupported module is worth what it can be repaired for. A used pump on a supported platform is a good buy; an orphaned system with no parts channel is a project.
Questions people ask about hplc equipment
What HPLC equipment does a first system need?
Pump, injector, column compartment, a detector matched to the method and a data system, plus the consumables the method needs: column and guard, fittings and tubing, vials, solvent handling, filtration, a vented waste arrangement and standards. Budget the consumables separately from the modules.
Which decision is hardest to change later?
The pressure class, because it decides which columns the system can ever run, followed by the detector set and the data system. Modules and consumables are easy to change; those three are the platform.
Is used HPLC equipment sensible?
Often, module by module on a platform that is still supported, with a qualification report and a performance check on arrival. An unsupported system with no parts channel is not cheap at any price.