Advantages of curved collision cell

[tswapna]

Hi,

can anybody highlight me advantages of curved collision cell over linear collision cell. Thanks in advance

[sassman]

I'm not aware of any instruments that use a curved collision cell. I can't think of any real advantage of such a technique. Something like an orthogonal source design has the obvious advantage of noise reduction, but I don't see how it would help in a collision cell.

[Ken]

Hi there.

Curved collision cell? It must be the latest product from AB's 5500 series MS/MS system. The curved collision cell, I guess will enables higher speed of transmission and thus, eliminating potential cross talks; this also speeds up analysis time and thus, enables more analytes to be analysed.

Also, it's also integrating an advanced electronic technology, the polarity switching has been pushed down to app. 50 ms, and this will definitely helps in analyzing complex matrices much easier !!!

Actually, I learned from some sources that this system is really fast and highly sensitive; even better than the 5000 series in term of sensitivity and I cant wait to see more of the system and learn about it; again, Applied Biosystems has pushed the MS technology to another level; first with the 5000 series and now, the 5500 series - the world's most sensitive system? Not being bias, but I guess no other systems came close to disputing that from AB.

Cheers!!!

[Kostas Petritis]

It must be said that the curved collision cell was first introduced by Varian and now adopted by Applied Biosystems. I know that Varian has patended it so I am not sure if they pay royalties to Varian (which I doubt) or they managed (or think they managed) to go around it.

Ken, maybe you can share with us how more sensititive and faster is the 5500 from the 5000?

[Schmitty]

I recall seeing/reading that the 5500 is 5X as sensitive as another instrument. Since they did not bother to name the instrument, I am forced to assume they mean the next most sensitive ABI product.

Also, it has 50ms switching between polarities, which is a huge gain over the current 700ms switching on the 4000 and 5000s. I do not recall what the Agilent intrument's switching and settling time are, but they were much better than the 4 or 5000's.

[Ken]

Hi Kostas, once I get more info from AB's application expert that are schedule to meet me this coming wednesday on this latest product, I will update you guys.

Maybe I can find out about the so called Varian patent on the curved collision cell as well.

Cheers...

[Kostas Petritis]

Maybe I can find out about the so called Varian patent on the curved collision cell as well.

Ken,

When it comes to US patents, it is very easy to verify things. I added a link below with the patent. As you can see it is indeed the curved collision cell, it is a patent from Varian and was filled in 2000 and published in 2003. Varian has implemented the curved collision cell in their 320-MS LC/MS/MS triple quadrupole several years ago...

Schmitty, the Agilent polarity switching is currently at 100 ms and they claim up to 300 MS/MS transitions per sec (I assume without big losses of sensitivity)

http://www.freepatentsonline.com/6576897.html

[tswapna]

Dear All,

Thanks for your inputs. But Waters claims 5 ms polarity switching in thier TQD & Xevo. Then will it be more sensitive than AB's 5500 series as AB says 50 ms polarity switching.

Can anybody highlight me the true differences of AB with Waters.

Thanks in advance

[richa_malhotra]

I dont see a great advantage in waters claim of 5 ms polarity switching as they never say what is the dwell time or transition time which is very important.

Moreover I have not seen any scientists who is really working on polarity switching. I can strongly say that its a sales gimmick of waters.

I do agree with Ken and the curved collision cell wll have advantages of higher speed of transmission and thus, eliminating potential cross talks; this also speeds up analysis time and thus, enables more analytes to be analysed.

even me too is awaiting more technical information about AB's 5500 mass system and will highlight its advantages later

[Kostas Petritis]

Again to be fair, Waters provide information on dwell times vs performance, see the link below:

http://www.waters.com/waters/nav.htm?lo ... d=10064408#

Polarity switching can be useful for some people/applications.

I also suggest to take a look at the spelling that AB has choose for their new collision cell (i.e. "qurved" and not "curved").

I have nothing against AB products, on the contrary I like them, just playing it devil's advocate.

Finally, Ken and Richa you look like you have a fundamental understanding of mass spectrometry ion optics so maybe you can tell us in laymans terms why the curved collision cell allows higher speed of transission and eliminating potential cross talk. You guys really nailed it down as according to AB: "The newly designed Qurved LINAC high-pressure collision cell accelerates ions through the collision cell, increasing the speed of analysis and eliminating cross-talk. Improving on the performance of the legendary LINAC collision cell results in shorter transit times across the collision cell".

[yangz00g]

Thermo uses curved collision cell too, 90 degree vs ABI 180. Eliminating cross talks could be a big benefit.

50ms polarity swtiching is still a "long" time if you are doing large scale screening (pesticides, drug abuse), e.g 100 MRMs positive and 20 negative. I am uisng an API system, so I have to run two screenings for postive and negative per sample. For this purpose, Waters holds the advantage.

With similar price to 5000, 5500 is really a "good deal".

[wuwei_online]

Yes, Thermo Vantage’s Q2 is 90 degree,we have the lasted Thermo's TSQ Vantage, the most sensitivity MS for Thermo.
API 5500’s Q2 is something like Varian, which I saw 3 years ago (couldn't remember the product number), for the Q-jet will be closed in API 5000 due the the patent issue with Thermo, dose API 5500 have the same issue?
We also have 2 set of API 5000 in our Lab, it’s about 2~3 times high than API 4000 in general, so API 5500 will more than 10 times than API 4000, right?
In geneal, API 5500 is more like Thermo’s MS with AB’s Ion sourse, it’s very strange!

I have another question for the price, is this just very close to API 5000?

[Kostas Petritis]

for the Q-jet will be closed in API 5000 due the the patent issue with Thermo, dose API 5500 have the same issue?

What do you mean by that?

[wuwei_online]

At beginning, AB claimed that API 5000 will 7~8 times' sensitivity than API 4000, due to the Q-jet and re-desined quadrupole system.

But after AB released the new for 6 months (about June, 2006), most US purchaser found the sensitivity is about 2 times than API 4000, and the baseline is really very high, for thr Q-jet is very close to Thermo's Q00 in TSQ, and there's some patent issue between Thermo and AB.

For API 5500 also have Q-jet, but have changed some design, is that for avoid the patent issue. If yes, API 5500 will good choise for US and EU. For some country, Q-jet's function will be used, and API 5000 will be enough.

[yangz00g]

I haven't heard of any Qjet patent problem, nor close (disable? removal?phase out?, hi, buddy, you need make yourself clear) of Qjet feature in API 5000.

The 5500 extends the Qjet length and makes improvments on lens, detector and collission cell. However, speed, rather than sensitivity, is the main selling point for 5500.

BTW, I am not working for ABI or have any affiliation with ABI.