Chromatography Forum

Hi there,

I have limited funds but am in need of an analytical/semiprep HPLC system, and am searching for advice for purchasing used HPLC systems. I have received quotes for several Agilent 1100 systems (with DAD, autosampler, degasser, ChemStation) that differ in price by up to ~$15K USD.

If you were buying a used Agilent HPLC, what factors would you keep in mind? Any advice for what I should look for or what I should stay away from? What's the best way to ensure I get a headache-free used HPLC?

Thanks for any insights!

We bought 3 used systems on eBay and paid less than 25K for quaternary pump, auto sampler, DAD, column heater) One system was assembled for below 20K buying all units separately.

Good point "SIELC-Tech". I just look a look and there are a few nice HP/Agilent systems and components listed on ebay. There are also some bad systems on there as well.

A few things to look for or ask about would include: Is the system cosmetically clean ? Is it filthy dirty and discolored (esp by the leak sensor) or covered in auction stickers or maybe Mr. Sharpie Pen marks ? Are all of the covers included ? What maintenance has been performed ? For detectors, is the lamp new ? If so, is it a factory lamp or aftermarket one ? Are all of the low pressure lines, bottle heads and associated parts included ? Has the system been decontaminated (some were used with radio-nucleotides or blood plasma/clinical samples) ? Does the seller have answers to these questions ? If not, go find one that does know about what they sell.

That should help get your started.

Thanks very much for your quick feedback! I greatly appreciate it.

One aspect to think about is how you are going to control the HPLC.
The issue here is differences in firmware of the modules (especially if these are of different age).

Simplest is if you are using (quite new version) Chemstation. Then firmware in the modules can be updated without any problems.

Hand held terminal to my knowledge can not be upgraded without exchange of electronic parts. So if there is newer module firmware (and it can not be downgraded) - you will not be able to control the instrument.

If you want to use other software to control the HPLC - be aware, that none of them to my knowledge can perform test/service operations which are available in Chemstation. So you even can not make UV lamp test or check how many ON hours it has, autosampler service positions are not avilable etc. That means even smallest hick-up will need a service call.

This kind of situation we have here. An older Agilent 1100 HPLC with handheld terminal was aquired. To connect system to enterprise Empower server, modules firmware was upgraded which made the terminal unusable. So now we have no way to use diagnostics/service functions.

I just want to clarify some information in "Rolandas Plausinaitis" post.

Regarding the flashable firmware in the 1100/1200-series modules. With the exception of some of the very early modules (1995-1996), all of the modules can be upgraded or downgraded with the appropriate firmware (via the G1323, ChemStation, PC RS-232, Flash card in G1323, or LAN connection). The first modules built in the series had a limitation in this area and require an updated mainboard to function as the newer modules do. Many of the early modules were updated by their owners, but not all so it pays to double check which main board in installed in the first few production runs.

Regarding firmware upgrades in the hand held G1323 series module. It can absolutely be upgraded just like the other modules (flashable), but has limitations. The earliest version, G1323A, accepts firmware update revisions, but it does not have the available memory to accept any of the more modern firmware updated needed to run the more recently introduced modules. It is no longer supporter. The G1232B version has more built-in memory and supports many more firmware updates until it too was recently made obsolete. The newer G4208A hand held unit has even more memory on-board and can support all of the new modules.

The software system you choose to control the system with (e.g. ChemStation, Empower...) will determine to a large degree which firmware revisions are appropriate for your modules. Firmware revisions and installation instructions can be found on Agilent's CAG web site as well as the factory ChemStation software disk.

If you do choose to operate the system without ChemStation software, then I would recommend you purchase a control module that will work with the modules you have on hand so you can, as "Rolandas Plausinaitis" points out, still have access to all of the diagnostic functions.

If you choose to operate under ChemStation software, then be sure to select a revision of ChemStation that supports all of the different modules you have as well as the Operating system and communication method you plan to use. Their are numerous permutations and selecting the wrong options can be a very expensive mistake. *This is a generalization, but using the newest revision of ChemStation can be a BIG mistake (example, the RC.NET based B.04.02) unless you have a newly manufactured module that did not exist until that revision of software was released. Otherwise, always use the earlier versions which are generally more stable.

We've done such business with both Quantum Analytics and Alpha Omega and been satisfied.

Along these same lines of selecting a used Agilent 1100: If given the choice between a Agilent G1312A binary pump or G1311A quaternary pump, which would you go with?

...I will only need to run 2 solvents in gradient mode and thus has little use for the other 2 solvents of the quaternary system. Are there pros/cons to the quad pump that I should consider? Should I expect that the quad or binary pump to be cheaper/easier to repair when something goes wrong?

Thanks much!

Quick answer is go with the Quat Pump and Degasser.

Quat pump offers useable flow rates from 50 ul/min to 10.000 ml/min. You can choose ANY of the four solvent bottles in ANY order and combination. *The 10 ml/min speed is really handy when flushing solvent out of each line or the degasser. The extra bottles are useful for having a separate flushing/washing mobile phase or just an alternate mobile phase to choose from. You can never have too many choices...

Binary Pump offers flow rates from 50 ul/min to only 5.000 ml/min. Get a degassing system with the Binary. It is not included, but will run better. You can only choose one solvent bottle from each “sideâ€

We have both quat pump system and binary pump system. Both were fine, just a little different. I'd also go the route of quat pump system for your current and future usage.

The binary pump pumps exactly what it says, even when there is no back-pressure. I'm not sure if this is true of Agilent's quaternary pump; it certainly isn't true of all quaternary pumps. In any case, pumping accurately against no back pressure is a fairly esoteric need!

"lmh": The quat and Binary pumps can both pump anything w/o issues. They will easily pump AIR under no back pressure and this is one of the reasons why they are so easy to prime and also do not have cavitation problems where check valves stick.

It is an older design from the mid 1980's that has remained nearly unchanged or improved upon for about twenty-five years. An excellent design that many other non-Agilent HPLC manufacturer's recommend if you want a reliable HPLC pump, often over their own products, esp for LC-MS.

You can have much more flexibility in method development with quaternary pump. You don't need to premix a lot of mobile phase. We usually use one channel for ACN, one for water and two for concentrated buffer/acid solutions (100 mmol or 1%, respectively). You can do any type of single, double and triple gradient without premixing or changing bottles.

Amesy there are a few things yes to consider regarding the pumps

HPG
they are more expensive to buy and to maintain (more check valves). the operation like stated is different with the access to only 2 channels out of 4 every time (and that is considering you have 4 and not only 2 which is more common in older models) the draw back is huge if you are going to use buffers. it is trickier to manage well with 4 lines and impossible to do automatically with only 2 lines, it needs to be done manually.
the advantage is in the mixing, it is done in the pressure side, so if you have no degaser, it is less of a problem, especially if you intend to do no pre-mixing (but I would strongly advise against doing this on regular bases).
the dwell volume is far less (50-350ul in most cases for 1.5ml for the LPG) and that is also an great advantage in gradient formation and does bring an added value in separation, this is also better for doing faster linear gradients or very slow changing gradients
(there is a reason most UHPLC pumps are HPG and not LPG)

LPG
cheaper to buy and maintain, easier to work with.
degaser is a must, and no it is not recommended to use non premixed solvents if you want to have a more robust method. the non premix approach is good i thing only at the beginning of method development for early stages of the method. and also with buffers it increases the need for maintenance and faulty check valves.
one main advantage of the LPG is if you work with buffers you can use A-B for your application and C-D to wash out the buffer with water and wash the column with an organic solvent

3 solvent gradient method is never robust and never user friendly. I always advise against such methods since they need to much trouble shooting when moved to another vendor system

overall unless you do have a need for it for your application it is easier and simpler to use the LPG
an example where an analytical HPG is better then an LPG
a protein application where the linear gradient goes 0-10% ACN+0.1%TFA in 30 minutes.
in such a method many LPGs will show a step or a curved shape instead of a linear, the HPG will not.

Hi All,

Could go to hplc4sale.co.uk and see what we have got - agilent systems fully serviced with warranty from £10,000 ($15,000 approx)!!!