Chromatography Forum

Anyone noticed the variety of LCMS grade acetonitrile (& others) out there? and the variety of prices? I see 4x4L cases from $1,335 to $253 and everything in between... depending on supplier and brand name... They all say LCMS grade and show certificates of analysis that look great... am I naive to just buy the cheapest?
Please weigh in with your un/favorite brands or philosophy on solvent brand / grades.

thanks!

Helen

I don't think you're naïve at all. I've noticed that equipment suppliers are always most keen that we use the highest possible grades, presumably because they want to show high sensitivity and low background on their instruments. Nevertheless, there are lots of applications where the very highest grade isn't really necessary. If you are running a highly targeted analysis, background ions don't matter. If you are not interested in very small peaks in full-scan data, again, a few background ions don't matter. In fact they're useful in accurate mass work as a lock-mass.
Acetonitrile prices seem to fluctuate quite alarmingly. I am not convinced that the correlation between quality and price is 100% reliable.

One test a former coworker of mine did to prove to a salesman that the ACN he was peddling was not of a high enough quality was to run a gradient. In channel A was the current ACN, channel B was the salesman's ACN and a gradient of 100% A to 100%B was run and monitored with a diode array. He showed the salesman that there was still UV absorbing impurities in the ACN.

But, if you're running LCMS, then those impurities may not matter to you.

All of my LCMS work has been run in MRM mode so solvent grade has never really been a problem for me. The only thing that gives me problems and requires special grade solvent is running purge and trap and needing purge and trap grade methanol, and sometimes finding that which is clean enough can be difficult. Always have trouble with chloroform contamination.

Thanks imh. We do a lot of untargeted work so I like to look at a relatively clear full scan view, but ultimately the software sees through it anyway. Well, I ordered the cheapest LCMS grade, we'll see how good it is!
Helen


[quote="lmh"]I don't think you're naïve at all. I've noticed that equipment suppliers are always most keen that we use the highest possible grades, presumably because they want to show high sensitivity and low background on their instruments. Nevertheless, there are lots of applications where the very highest grade isn't really necessary. If you are running a highly targeted analysis, background ions don't matter. If you are not interested in very small peaks in full-scan data, again, a few background ions don't matter. In fact they're useful in accurate mass work as a lock-mass.
Acetonitrile prices seem to fluctuate quite alarmingly. I am not convinced that the correlation between quality and price is 100% reliable.[/quote]

Nice! I like the 'head-to head' comparison. We do record UV scans, mostly to monitor an internal standard that has a nice yellow chromaphore, the rest of the work is on the LCMS.
Helen


[quote="itspip"]One test a former coworker of mine did to prove to a salesman that the ACN he was peddling was not of a high enough quality was to run a gradient. In channel A was the current ACN, channel B was the salesman's ACN and a gradient of 100% A to 100%B was run and monitored with a diode array. He showed the salesman that there was still UV absorbing impurities in the ACN.

But, if you're running LCMS, then those impurities may not matter to you.[/quote]

Hi Helen,

Can you please share me a couple vendors that offer less expensive acetonitrile? I'm trying to cut our lab expense, thank you very much!

X

Anyone noticed the variety of LCMS grade acetonitrile (& others) out there? and the variety of prices? I see 4x4L cases from $1,335 to $253 and everything in between... depending on supplier and brand name... They all say LCMS grade and show certificates of analysis that look great... am I naive to just buy the cheapest?
Please weigh in with your un/favorite brands or philosophy on solvent brand / grades.

thanks!

Helen

hey X

I just went through VWR searching for "acetonitrile LCMS" there's a whole range of prices to choose from. I bought the BDH brand, your price depends on whatever discount you get, but we paid US$253 for a 4x4L case. I haven't tried it out yet, but BDH is a brand I recognize at least - and its "LCMS" grade so I'll have some come back if it doesn't turn out great!

good luck

Helen






[quote="X"]Hi Helen,

Can you please share me a couple vendors that offer less expensive acetonitrile? I'm trying to cut our lab expense, thank you very much!

X

[quote="hfredricks"]Anyone noticed the variety of LCMS grade acetonitrile (& others) out there? and the variety of prices? I see 4x4L cases from $1,335 to $253 and everything in between... depending on supplier and brand name... They all say LCMS grade and show certificates of analysis that look great... am I naive to just buy the cheapest?
Please weigh in with your un/favorite brands or philosophy on solvent brand / grades.

thanks!

Helen[/quote][/quote]

Personally I found the UPLC and HPLC acetonitrile from Biosolve brand satisfying regarding the quality/price for doing LC/TOF work. Of course everyone's mileage may vary

Thanks you very much Helen! I searched and got $952 per case, how could you get such a great discount? buying a lot?


[quote="hfredricks"]hey X

I just went through VWR searching for "acetonitrile LCMS" there's a whole range of prices to choose from. I bought the BDH brand, your price depends on whatever discount you get, but we paid US$253 for a 4x4L case. I haven't tried it out yet, but BDH is a brand I recognize at least - and its "LCMS" grade so I'll have some come back if it doesn't turn out great!

good luck

Helen

There's a bunch of smoke and mirrors with chemical pricing with the large vendors. If your usage is large enough, or if you have a contract with that vendor, the discounts on solvents can be considerable.

Hey X, glad you got some cheaper ACN - we're a reasonably large institution so I guess we get a good discount, or our procurement people negotiates hard
I agree with 'consumer prod. guy' - the price of science stuff generally is a mystery, even with our discounts I often find ordinary lab stuff is cheaper on Amazon!




[quote="X"]Thanks you very much Helen! I searched and got $952 per case, how could you get such a great discount? buying a lot?


[quote="hfredricks"]hey X

I just went through VWR searching for "acetonitrile LCMS" there's a whole range of prices to choose from. I bought the BDH brand, your price depends on whatever discount you get, but we paid US$253 for a 4x4L case. I haven't tried it out yet, but BDH is a brand I recognize at least - and its "LCMS" grade so I'll have some come back if it doesn't turn out great!

good luck

Helen[/quote]

Thanks Helen and Consumer Products Guy, I'll talk to our purchasing department to see if we can get some discount

[quote="hfredricks"]the price of science stuff generally is a mystery, even with our discounts I often find ordinary lab stuff is cheaper on Amazon!

Ha! I was buying a replacement o-ring for an air sampling device from Thermo Fisher and their quote was $35 for ONE nitrile o-ring. I got out a ruler and calipers and measured it, turns out it's a standard size you can get anywhere. I got a pack of 100 for $8. That's over 400x cheaper. Absolutely absurd.