GC-MS/MS : Agilent 7000B or Thermo quantum xls ?

[atrazine]

I 'am completing the purchase of a new GC-MS/MS to analyse pesticides in food and environment. Waters, Thermo and Agilent are the companies that have answered for my specifications. Samples were sent to the application labs and results show that Agilent (7000A) is a little more sensitive and a little more accurate than Waters (Quattro micro) and Thermo (Quantum) but a great problem comes from stability of the signal with Agilent. After 30 injections (spinach and maize matrix), sensitivity decreases of about 20 %. For financial reasons, Waters has been eliminated. Thus I have to choice between Agilent GC-MS/MS 7000B and GC-MS/MS Quantum xls from Thermo. Could you give me your experiences with this systems about sensitivity, signal stability, accuracy, linearity ? What about the softwares (intuitiveness, abilities,bugs,...) for Masshunter (Agilent) and Excalibur + QuanLab form (Thermo).

thank you

[yangz00g]

I don't have a Quantum xls, but have dealed with a Quantum QC for the past two years. And it's a disaster, I have to say.

It was bought brand new and only three months later it began to have huge "signal stability problem. For instance, the peak area of the 10th IS could drop to 10% of the first IS. In the past two years, one full-time technican spent 50% of the time to fix the instrument, and more than ten Thermo "experts" came over, but the "signal stability problem" couldn't be fixed until recently they added a backfush system (temporatory, only good for three weeks so far). I was amazed to see the service charge was over 100K, which was paid by our service contact. Everything form GC injector all the way to Q1 (yes, not Q0) has been repalced and "upgraded", and I 99.9% suspect that we bacome a trial base for them.

I am sure the XLS has a newly released ion source claiming to be better for heavy matrices, but keep your finger crossed.

BTW, we are analyzing pesticides in food additives.

[stb75]

Atrazine, from what you write, I would suggest that you also include the Chromsys/Chromtech Evolution GC-MS/MS in your decision. It's been on the market for 4 years now with many happy customers in several continents. It is basically an upgrade to an existing 5973 or 5975. The original source, detector, GC, Q1 are retained, and the GC, and the sensitivity spec for upgrading a new 5975 with Triple Axis detector is 750:1 for the 272>222 transition of OFN. Chromsys (US) and Chromtech (outside US) will gladly run samples to demonstrate how well it works. For data analysis, Masshunter is used. You can call Chromsys at 703-780-1500 or email info@chromsys.com

[bhahn]

They are all exceptional instruments, in their own way, but it comes down to software and the application. Send me your specs at [url]bhahn@aoti.net[/url] and I will be happy to quote you a system (new, if you like) that will hit your lab running.
Good luck,
Bill