Which GC/MS/MS is better? Varian 320/325 or Agilent 7000B

[trozen]

yangz00g,

thank you for the reply and sharing your experience.
I have this machine since the end of 2009 and it was not usable until the upgrade to XLS (new ion source and Q0 installed) due to dramatic decrease in sensitivity just in a few injections.

the GC was serviced 3 times (it's the 3rd CPU board now), autosampler AI3000 did not work our of the box (changed to CTC Pal)

now it looks like adequate, hopefully it will be stable enough, because we need it to be good

the service.. yes, yes, yes..
(I also hate the reporting capabilities of Xcalibur / Xreport, but it should be a new data reporting software launched soon, Thermo works on it)

[hermo71]

I've upgraded my TSQ Quantum GC to XLS and now it's working fine. I'm running without problem 280 pesticides (560 srm transitions) in 18 min, with LOD well below 10 ppb. I don't think that both Varian and Agilent can do it...))
The new software QuanLab is very powerful...and better than Xcalibur

[giacomo56]

Congratulations....great feat....but being a nerd I couldn't resist so I went to the Agilent web site and found this......copied straight from their website............................. AGAIN great accomplishment. !!!!

Two ready-to-use GC/MS/MS Pesticide Analyzers are available for ultimate performance and flexibility:

Option 1 delivers highest flexibility and lets you add GC detectors and is easily scaled for shorter run times. It includes a method based on Agilent’s Retention Time Locked (RTL) GC/MS/MS MRM database (500+ pesticides) using constant pressure mode with post-column backflush.

Option 2 delivers top performance, shorter cycle times, and reduced carrier gas consumption. It features a method based on the USA Targeted Pesticide List RTL GC/MS/MS MRM database (200+ pesticides) using constant flow mode with mid-column backflush.

[hermo71]

Hi Giacomo,

consider that Thermo has just publisher a Pesticed Reference Database with more than 800 SRM conditions for pesticides...and an apps note with 1200 trasitions in less than 34 minutes. Thermo has a big experience in backflush system...i tried both Agilent and Thermo backflush with real and very hard samples, and Thermo was better.
By the way, my final choice was thanks to a huge demo on real samples, and the TSQ Quantum GC was superior to 7000B. Now with the upgrade to TSQ Quantum XLS, I've doubled the sensitivity and robustness.

I don't trust the application notes published by these vendors...I want to test the instruments with my samples..)

[hermo71]

Giacomo,

maybe I'm wrong, but from all your answers I can deduce that you are an Agilent salesman.. Are you Italian?

[yangz00g]

maybe I'm wrong

Yes, it highly likely you are wrong. I have no experience with Agilent backflush, but the Thermo one (pre-column) is horrible. They even could not offer or find a good way to mount the connecter onto the wall to reduce vibration (prevent leak). If you read my previous posts, you will see.

Did you have very good experience with Quantum GC too? If you did, please share. I kown at least two persons,including myself, on this board had bad experience with it, the data quality is wrose than an Agilent GC-single quan-MS.

Hermo, do you have a link to the Thermo pesticides database you mentioned, web-search yielded no result. Thanks
BTW, I have no affiliation with any instrumental manufactures.

[giacomo56]

Hermo71 are YOU a Thermo Sales rep.....I just like looking for challenges...heck I took a NYCity Policemen test just to see how I would do....never intend in being a cop.....just to see where I would fall in the ranks.