HPLC Solvent Selectors...?

[Roxanne42]

Hi there,

We have an Agilent 1100, equipped with a binary pump (G1312a) - so that we can have two bottles of solvent on each line but can only select one of the two for each line.

Any good suggestions for solvent selectors out there that would allow us to have more than two bottles on each line...?

Just looking to see how people have set up their system really...

Also thinking of getting a column switcher (Chiralizer) - anyone find these particularly useful...?

[Larry Miller]

Agilent sells column and solvent switching valves that work with the 1100. We have them on nearly all of our Agilent systems. These valves are cheaper than the Chiralyzer and can be selected via Chemstation software. Your Agilent sales rep should be able to provide all required information.

[Roxanne42]

Actually, it would appear we already have this valve (but on a binary pump, this still only allows the selection of one of two solvents on each line (*separately*)). I was wondering about additional valves one could install (such as a Valco valve right where the solvent line comes into the system).

I spoke to Agilent but that was the only thing they sold (the one that goes in at the intake line, inside the system).


Thank you though!

[mardexis]

Agilent sells a 12 solvent selector valve but it is not called that. Just look at the optional valves available and the thirteen port valve is a 12 solvent selector. You could also just add manual low pressure three way valves to mulitplex bottles to each line going to the HPLC if it is for method development.

I also have a couple of the the six column selector valves from Agilent which I'm happy with. I considered the system from chiralizer. It is more expensive but also provides temperature control which is not available with Agilent. I run my mobile phase through the heat exchanger so the temp is close to what I want but not very tightly controlled. The up side is that the valve simply plugs into the CAN bus of the Agilent stack and has some immediate functionality in chemstation.

[HPLCCONSULT]

"Roxanne42": I work in a contract lab. Sounds like you have a standard Agilent 1100-series Binary Pump. These are designed to use either TWO bottles or FOUR bottles (w/optional add on valve) to select one bottle from each 'side' only. They do not allow full random access of the solvent bottles. Agilent's Quaternary Pump offers full random access to all four bottles and includes the degasser module (extra on the Binary Pump) as well. We have found that most chromatographer's are better off only buying the Quat pump and not the binary. The QUAT pump has ~ 900ul delay volume, full access to any bottle or combination of bottle, excellent flow stability from 100ul to 10.00 ml/min (the binary only goes to 5 ml max) and is less expensive. BTW: I do not work for Agilent, but have spent a great deal of time testing the Binary and Quaternary pumps in our labs. Buy Quat pumps ! If you need more than four solvents, then 1) do as it was suggested to us by another company, add another quat pump to your 1100 and you will gain four more solvent choices or 2) buy an inexpensive solvent selector valve (low pressure valve such as the one offered by Hamilton or Agilent) which connects to one of your bottle lines (in your case the second pump head) and goes to a ten or twelve port valve for solvent selection. Keep in mind that these cheap low pressure valves will require that you flush each bottle line out before use and will add a delay in time to gradient runs as they are not routed directly to the pump head (must go to the valve first).

As for the HPLC column selectors, we use several in our labs. I do not know why people state the Chiralizer products are expensive as they are actually less expensive than all of the ones I know about (Rheodyne, which makes them for Agilent, Phenomenex and many other companies/PE/Valco). One of the basic Chiralizer units we have holds up to five columns and one pre-plumbed by-pass line and cost just over $3K (agilent version is ~ $6K). They also make versions which hold up to ten columns and have temperature controlled versions (we have one of those as well) which are expensive, but work great. I think that the people who said they "are expensive" must have been comparing the wrong models together (e.g. Chiralizer heated/cooled verisons to the ambient temperature models made by other companies such as Rheodyne/Agilent). *Always check the source of your info... it may come from a sales person ! HPLC Column selectors save time, increase productivity and accuracy plus some offer software interfaces which control them under your existing HPLC software (We use Chemstation as well as other types of software with the Chiralizer brand LC Spiderling column selectors are all controlled under the same software. Very easy to use). *I sound like an advertisment, but that is because we would not want to be w/o them.

[DR]

^ - is generally the case from most vendors these days - if you want high pressure mixing during gradient formation, you get a binary pump system and choose 2 of 4 available bottles, if you need ternary or quartenary (sp?) mixing, you pretty well have to go with a low pressure mixing system which means you have a proportioning valve and small mixing chamber before the inlet of a single pump. These systems are generally slightly cheaper than the binary option, they're more flexible and frequently deliver a quieter baseline at the extremes (eg - when you're at 99%A, 1%B). The only drawback is that you have to be a little more diligent about degassing things as you can get outgassing on mixing with certain solvent combinations (tends to be less of a problem when mixing under pressure).

[unmgvar]

Hi Roxanne 42,
the system you have is a HPG so by definition you can only create a 2 solvents gradient. i would strongly advise against any engeneering attempts to try and have more solvents used.
i also would advise that if you find yourself developing a 3 or even worst 4 solvents method, then stop. rethink. start fresh. 2 solvents is "bad enough". you never know when you will need to transfer that method to another instrument or lab.
as for column switching, it is a good thing if you have the need for it.
for example rheodyne as a 2X7 port 6 position valve that can let you switch between 6 columns.
very handy if you deal with method development and you wish to maximise productivity because of the workload. just make sure that you have the workload and the capacity to deal with the increased amount of data that you generate

[HPLCCONSULT]

"unmgvar": I think you missed "Roxane42's" point. She wants the ability to select more bottles (as in different solvents/mobile phase) than are available with the A1/A2 : B1/B2 style system she has now (very limited solvent selection with this high pressure gradient system). She can only choose one bottle from one "side" at a time (e.g. she cannot select bottles A1 & A2 together). A quaternary pump would offer her the choice of any four bottles instead of any two.

BTW: I agree that if you find yourself developing ternary and quaternary systems to separate compounds, then you really should go back to square one in method development. Simple is better.

[Paladin]

Folks,

We're looking at being able to add more columns & mobile phases to our LCs. I have quotes form Agilent which are rather costly. What brand of column & mobile phase selectors do you recommend? I need something that can be added to an Agilent 1100 or 1200 easily.

Thanks