Agilent vs Thermo

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

46 posts Page 1 of 4
Hello,

finally I got the funding, now I can sell my old GCQ Plus and buy a new GC-MS.

I narrowed to 2 options:

Agilent 5977A MS + 7890B GC vs Thermo ICQ MS + Trace 1300 GC

In the same price frame Agilent offered a slightly less advanced system meaning it has a diffusion pump where ICQ has a turbomolecular pump, and the EI source is not their Exctractor EI source but a normal Inert EI source where ICQ has their ExtractaBrite EI source.

This combination for Thermo gives a 1500:1 S/N for 1 pg/μl OFN and a 10 fg/μl IDL.
This combination for Agilent gives a 300:1 S/N for 1 pg/μl OFN and a 30 fg/μl IDL.

OFN - octofluoronaphatalene
IDL - instrument detection limit

Which of them do you consider to be best ? Please advise. Your experience with these brands is invaluable.

Thank you,
Vlad Popovici
Looking on the specs it seems the Thermo wins hands down..

Personally I would always prefer a turbomolecular pump over a diffusion pump.. they pump down faster.. maybe not a big issue in the relative small vacuum chamber of a GC/MS today but still..
Kind regards
Leadazide
I'd choose a turbo over a diffusion pump any day of the week. The simple fact that you don't risk getting pump oil all over your vacuum chamber is worth a lot in my opinion.

When purchasing an instrument it's also always important to compare the potential suppliers in terms of service and support (even more so than comparing specs), which may differ strongly depending on your region.
I'd choose the Thermo over the Agilent. I find the software a lot easier to work with (might be because I'm mainly used to Thermo) But it's al lot more forgiving too. The agilent-software tends to jam (is that a correct term for it :?: ) if you try to do a few things at once.
What I like most on thermo soft is that each change in integration of a standard or the exclusion of a calibration point will cause an instant calculation of the QC and unknowns, whereas the Agilent requires a batch-reproces that takes a lot of time.
LiVD wrote:
When purchasing an instrument it's also always important to compare the potential suppliers in terms of service and support (even more so than comparing specs), which may differ strongly depending on your region.



Yes.. very true! Also consider all the side line support like if support on the phone is chargable or free.. if there is a possibility of application support..

It all counts!
Kind regards

Leadazide
Unless nearly all your work involves ultra-trace analysis where you are scratching after the last little bit of detectability (and even then the detectability of any given analyte usually depends more on the interferences in the sample than it does onthe instruments ability to put a blip on a flat baseline) the LOD is only one (and probably not the most important one) of several factros you need to be considering.

Peter
Peter Apps
I'll chime in on the Agilent side. I have used nothing but Agilent equipment in my career and have been extremely pleased with the results. The 6890/5973 GCMS systems I have are very rugged and have done everything I've ever asked of them. They are easy to maintain by the user. I've had precious few service calls over the years. I find the software to be very robust and it thinks like I think. That could be because I'm an "Agilent guy" so we've sort of trained each other over the years.

If I'm spending money on a new system, I'm probably not going any farther than considering Agilent. It's too big a risk for me to venture into the unknown of another instrument manufacturer to make a $100,000 mistake. Just my $0.02.
you have to be awfully careful about LODs from manufacturers too, because they have different attitudes and potentially different approaches to measuring. For example, S/N ratios depend on how they're calculated (in Thermo world even the Genesis and Icis integrators give values orders of magnitude different for the same peak, at least in my ancient version of Xcalibur for LC). Some manufacturers quote a LOD that they believe they can achieve on installation; others quote a LOD they believe will be achievable day-to-day on a reasonably maintained instrument.

Other factors of great relevance are oven temperature range, ease of maintenance of source, reliability, and probably loads more that I don't know about, being mostly an LC person.
Hello,

in fact all my analyses are trace analyses. The ranges I have varies from 0,002 ppb to 5 ppb. The matrix I analyze the most is potable water.

As for operating temperatures, GC domain is same for both: ambient - 450 °C, ion source is same for both: 350 °C.
Both have vacuum probe interlock to easy access the source without venting the system.

Agilent transfer line: 350 °C
Thermo transfer line: 400 °C

I cannot find information about Thermo quadrupole temperature, it is possible that is not heated separately and is heated by radiation from ion source. Agilent can heat it separately to 200 °C.

Agilent electron energy: 242 eV
Thermo electron energy: 150 eV

Agilent emission current: 315 µA
Thermo emission current: 350 µA

As for IDL, is calculated identically for both devices, eight sequential 1 μL splitless injections of 100 fg/μL OFN monitored for m/z 272. But for me the most important is the S/N.

One other perk of the Thermo system is the possibility to change the column without venting the system.
Agilent has one very nice option of Power Save, but sadly that is only for the system with turbomolecular pump, and that jumps to other price range.
Both systems have the option for one auxiliary EPC that permits column backflush.

I cannot judge the support since I never had a new system and hence no support for either Agilent or Thermo. One thing thou, Agilent stipulates in contract that if you use other consumable than Agilent, you loose your warranty. This means bye bye Restek columns and hello J&W very expensive columns.

Regards,
Vlad Popovici
Hi Vlad

Drinking water is about as clean a matrix as you will find, so it would make sense to go for the lowest instrument LOD. You could do some spectacular scale downs on sample size and preparation and still maintain LOD/Q, or even improve them depending on where the noise is coming from.

Peter
Peter Apps
"Agilent stipulates in contract that if you use other consumable than Agilent, you loose your warranty. This means bye bye Restek columns and hello J&W very expensive columns."
In my view, and for the purposes I use GC-MS, this disqualifies Agilent! It is now 8 years I bought an Agilent GC-MS and, yes Agilent GC-MS are robust but they do have quirks that Agilent is not able handle. ChemStation E is not well-suited in a lab with stringent backup and regulatory requirements. If the Thermo GC-MS is available with Chromeleon 7.2, I would definitely buy Thermo.
Hi,

well on initial offer there is no Chromeleon, only Xcalibur. Monday I will ask if Chromeleon comes with a price.

On the other hand Agilent is including both their software, MassHunter and Chemstation.

What I am most interested about is their historical brand problems or limitations. I am also interested in systems like Agilent 5973N, Agilent 5973 inert, Agilent 5975C to compare with.

For example Thermo is not heating separately their quadrupole.
Agilent doesn't have the feature to change columns without loosing vacuum.

Agilent liner change is harder, bottom golden seal is even harder.
Thermo is only exposing their ion source through the interlock where Agilent is exposing the lenses also.

Thermo has the possibility to use N2 as gas saver, flush and split gas, flowing He only into column, pulling an impressive 10 years of run time with only 1 He cylinder.
https://www.youtube.com/watch?v=eBt79umoBas&index=5&list=PLD821C7123EF4EBC4
Agilent has the Power Save option to spare 60% of the power on sleep mode.
http://www.chem.agilent.com/Library/flyers/Public/5991-2179EN.pdf

These are limitations. The problems I don't know.

Regards,
Vlad

Edit: It seems Agilent doesn't have a vacuum interlock at all. The one for Thermo demostrated here: https://www.youtube.com/watch?v=WKGCvLBGkAk&index=3&list=PLD821C7123EF4EBC4
I have been using HP/Agilent GCMS for over 20 years, have always used the Restek columns. If they disallow it now that is something new.

I also have used the diffusion pump models, and unless you will be cleaning the source often they are not that bad. If you ever want to try hydrogen as carrier the diffusion will pump it out better than the turbo pumps.

I agree that the E version of MSChemstation has more quirks than the older versions, but it seems the newest one is getting those worked out. I have not run MassHunter yet, but will have a 7000QQQ installed in about two weeks so will get to know it very well.

Are you looking to do semivolatile analysis on water or Purge and Trap for volatiles? We do both here, and currently are running 4 5973 and 2 5975 units. We did have to replace a turbo pump on the second oldest 5973 last year, it was about 14 years old, and we have replaced one side board on the oldest 5973, other than that we have just done routine cleaning on them over the years, never even use a service contract as the reliability has been good enough. I did both of the above repairs myself, just ordered the parts and installed them, but I did have quite a bit of repair practice back when we owned two 5995 HP units so I do have some experience at it.

Never used Thermo so I can't knock them, but can say I have been happy with my Agilents.

For sensitivity I am currently running the UCMR3 volatiles on a 5975 and we get a detection limit of 0.015ppb for 1,1-Dichloroethane in full scan mode on purge and trap at 30:1 split which isn't too bad.
The past is there to guide us into the future, not to dwell in.
Thank you James, this is very helpful.

We are not cleaning very often the source, since we are running it hot and we don't have A LOT of analyses to perform. However the turbomolecular pump helps huge with the S/N. Before entering the quadrupole, the non ionized molecules are swept away by the turbomolecular pump at a higher rate than the diffusion pump. I can say in my old GCQ, with a diffusion pump, I have A LOT of background noise.

We do have both volatiles and semi-volatiles but we do volatiles also with L-L extraction at lower temperatures. Later, we will opt for a P&T.

Agilent 5973N
All models S/N = 20:1

Agilent 5973 inert
All models S/N = 60:1

Agilent 5975C
Turbo pump S/N = 200:1
Diffusion pump S/N = 100:1

These I gathered from the datasheets.

The 0.015ppb is very nice, but you get that from your P&T after concentration, i guess. Anyway, the fact that you run these 2 devices for so many years means they are good and resilient. Bonus points for Agilent :)

Regards,
Vlad
The Agilent 5977A does not have a vacuum interlock for replacing the source without venting. It still uses a swing out side plate with the quads and source attached.

The big things you will like about the 77 are the heated quads and the triple axis detector.

You might want to ask about the Multimode injector. MMI makes cleaning a bit more dicey, but could give you some extra options like cold inlet and large volume injection.

I have a 75C and a 77A, both with the triple axis detector. The 75C was an early model that later had the triple axis installed, baseline was reduced dramatically and we picked up about a factor of six increase in s/n.

We have a plethora of 5973's, many with turbos that are over 15 years old. Agilent did a great job with that instrument platform. You can do a lot with them if you get creative. The 7890/5977 continues that tradition. I'm still pretty impressed with their instruments. A colleague of mine has a thermo unit with the pull-out ion volume and I have a couple varians with the pull out source as well. You still have to let them cool down to swap out, but the do get running very quickly after the changeout as long as you have spare ion volumes. That reminds me, if you have spare sources for the 73, they won't fit in the 77. You should ask about this, we got the extractor source, the column inlet guide is replaced by the ceramic spring, even for EI.

The transition to masshunter has been very difficult for me because I spend more time on chemstation based systems. It's all still there, lots of new features just in different places. Kind of like switching from windows XP to windows 8. One of these days I'll spend a day learning masshunter.

Get the turbo. If Agilent is still figuring out their packaging problems and you order the oil-less rough pump, you might score an extra DS602 rough pump as well. Don't let them take the DS602 back, it is a very quiet pump. First time I hooked it up I didn't think it was running until I touched it and felt a slight vibration. My ears from 20 years in the future have already thanked me.
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