Buying a Single Quad LC-MS system

[Dr Lou]

Hello everyone!

I would welcome input from you guys who have recently purchased an LC-MS single quad system.

I was pushing for a Q-TOF but have been priced out of that bracket. Wanted to have some LC-MS capability we are opting for a cheaper single quad.

We plan to buy the complete system - LC and all.

My current favourite is the Agilent because we have a single quad GCMS system from them.

I am wary of Thermo and Bruker simply because I do not want a Dionex LC.

We have an Ulitmate 3000 which is about 2 years old and frankly, is it poop. I could start a thread on it but in a nutshell pump seals go every 3 months (even though was use reverse phase solvents with no buffers/salts) and the autosampler has gone out of alignment and no one but a thermo/dionex engineer can fix it. It needs software code for the panel which they will not give out - why you can't perform and x/y adjustment yourself I do not know :-/

So, knowing that - what are your thoughts,

Thanks,

Louisa

[lmh]

I always end up saying the same things: if you can, get a range of manufacturers to run some test samples for you, visit them and have a look. Get them to put you in contact with some satisfied customers (if they can't, that says something...). I can't say whether Agilent are the best to get at the moment, because our Agilent single quad is now 12 years old (which is a useful statistic itself!). There are lots of manufacturers out there: you haven't mentioned Waters or Shimadzu, and if you find you like an instrument from Bruker or Thermo but don't like Dionex, do ask what other LC systems they can use. I assume Bruker can do Agilent LC systems (they always used to, but politics may be a problem now).

Be cheeky, too (reps have thick skins). There's a big price difference between a single quad and a q-tof. Depending on application, you might find an ion-trap would give you some useful capability at a price between the two. If you can, take a cautious look at the 2nd hand market; if you know what you're doing, there are bargains out there from time to time (especially when major pharmaceutical companies undergo extensive restructuring).

[bisnettrj2]

You can buy an MS without buying an LC from the same vendor - most LCs can be interfaced without issue to most MS instruments via a contact closure setup or other sending of a start signal, if not through the MS software directly.

As for single quad MS systems, you have Waters, Agilent, Shimadzu, and Dionex as vendors of both HPLC and single-quad MS systems (I think that's all the major players, might have missed one or two). I don't think Bruker or AB Sciex make a single quad LCMS system, and Bruker doesn't have a "traditional" LC, only nanoLC from what I can find on their website, same with AB Sciex, only a nano LC. Take the advice of many on this site from the various "which MS should I buy" posts and contact each vendor and have them set up a demo with your samples, your reagents, and your columns. Buy the one that meets your needs, is within your budget, and has good options for service and support in your area. I would definitely opt for a UHPLC front end, and Waters and Agilent have been in that market for a while, so that's food for thought.

I would look into a triple quad rather than a single quad - LCMS has a lot of low-mass noise due to solvents and salts, and doing an MS/MS experiment cuts out noise and gives a more definitive identification of a target compound.

Personally, I would look into a Spark UHPLC and an AB Sciex 5500 Q Trap, but that's just me.

[pigfarmer]

I assume Bruker can do Agilent LC systems (they always used to, but politics may be a problem now).

We have a Bruker FT-ICR from 2011 with Agilent LC system, I assume they would be able to do that with any other instruments they have.

[philco]

Hi Louisa,

I'll be up front about this piece, I'm Shimadzu UK's LC/LCMS and Life Science Sales Manager.

I'm not going to tell you how wonderful our system is as you'd rightly treat that with some suspicion

I would like to invite you to come up to Milton Keynes and have a look at the system in our evaluation lab. We'd be happy to run some samples for you and help tailor a system to your needs if you chose to work with us.

Please feel free to get in touch, my email address is stuart dot phillips at shimadzu.co.uk

Apologies for splitting the email address like that, I'm just trying to avoid spam!

Best Regards,

Stuart

[CE Instruments]

Shame you can't justify a TOF but they are not cheap. Unless you have a simple targetted analysis I would avoid a single quad completely. LC/MS generally gives molecular weight info. if you want to get more idea of what you have you either need accurate Mass or MS/MS Low on funds then you will not be able to afford accrurate mass and you cannot upgrade to it. You should either then look to find the funds to buy a low cost triple quad or look at Ion traps. Whilst Thermo might want you to buy Dionex LCs even they can control other makes and Bruker will have no problem providing Agilent LCs as they do not have their own mainstream LC system. Ion traps offer multiple stages of MS at little more than SQ prices

[Dr Lou]

Thanks everyone for your input.

I will now be considering an low res ion trap - as, depending on price, it will have MSn capabilities.

I have also asked about the possiblilty to use another vendors LC system.

I will also enquire about sending a sample out for a demo although we might run into trouble as we would need a NDA from each vendor before we do that.

[lmh]

You should have no problem getting an NDA from any manufacturer. They want to sell equipment, not nick results!

In choosing between a trap and a quadrupole, think of the work you intend to do. Quadrupoles, whether single or triple, excel at looking for fixed masses (or fixed transitions for a triple). In SIM/SRM mode, they should be far more sensitive price-for-price than a trap. Traps excel in full-scan modes, and will give nicer full scans and daughter ion scans. Modern triples, in my limited experience, are truly awful for full-scan work because they've been strongly optimised for sensitivity, and will show up every tiny blip of dirt imaginable in sample or solvent.

Yes, a single is a lot less selective than a triple, but it's still a lot more selective than an HPLC.

Don't forget to check the software suits you too.

[Mass Spec Detectives]

Good day,
Mass Spec Detectives sells refurbished lcms systems at very reasonable prices. Our Qtofs start @ 20k USD plus shipping etc.
Regards,

Raymond