ICP MS iCAP Q

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David Spiteri
David Spiteri's picture
ICP MS iCAP Q

 Dear All,

We have had an iCAP Q ICP MS installed for the last couple of months. Unfortunately as from July we have been having problems with performance checks. Autotuning fails, mass calibration fails, cross calibration fails. Tubing for sampler has been changed, torch has been changed, cones and lenses cleaned. We are at a loss.

Could anyone who has had similar problems guide us through a solution?

Many thanks

stephen99
stephen99's picture
Hi, I think a little more

Hi, I think a little more info is needed.  What do you mean by "fails"?  Is the autotune/performance checks failing on sensitivity (ie not enough counts) and if so on what masses?  Is it failing due to a high Ce/CeO ratio?  Can you tune manually to get acceptable instrument response?  Are you in STD or KED mode?

Have you tried going back to the initial settings your engineer put in place with the installation?

Mass cals and Cross cals generally fail if the tune has got so far away from standard settings that it can't identify the peaks it needs so that may be the cause of that.  I suspect that if you get the tune right the mass cals and cross cals will follow.

Have you spoken to your Thermo rep about this problem?  If your computer is connected to the internet, Thermo engineers can look at your instrument remotely and may be able to diagnose the problem.

Appologies for the dozens of questions and if I'm stating the obvious but without more details it's difficult to suggest a specific solution.

David Spiteri
David Spiteri's picture
 Hi, thank you very much for

 Hi, thank you very much for your response. I tried attaching the files of both the autotune and the performance checks, however the files were too big to attach.

In a nut shell the failures are due to:

115In at 155,962 CPS (greater than 30,000)
59Co at 51,603.0CPS (greater than 30,000)
35Cl.16O at 16,572.0

As regards autotune the problem is:

107%;font-family:"Arial","sans-serif";mso-fareast-font-family:Calibri;
mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:
EN-US;mso-bidi-language:AR-SA">Readback value of CCT1 Flow Readback is not in tolerance.

We have tried to contact thermo personnel, however no reply has been forthcoming till now. 

We are using KED mode

stephen99
stephen99's picture
There are a couple of issues

There are a couple of issues here.  The values you’re quoting are actually passes (155k is definitely greater than 30,000!) so I suspect it’s failing on stability rather than total counts.  Also, the figures for 115In and 59Co are very high for KED mode (assuming you’re using the standard 1ppb tune solution), in fact they look like they’re typical values if you’re in STD mode.
 The error message you’re getting implies that there is a problem with the cell gas.  It means that if the instrument is detecting that the collision gas flow isn’t what you’ve set it as, so if you’ve set the collision gas flow to 5 ml/min, it’s actually something different, say 3 ml/min.  That said, I have no idea what the tolerance of this is so I can’t tell you how far out it is.  The implication from the 115In & 59Co counts is that there’s no gas getting through at all, so you might want to check your gas lines and regulator for leaks.
 Regarding the 35Cl16O value, this parameter is always a pig.  In fact it took my installation engineer pretty much all day to get it to pass when the instrument was installed and after I spoke to the instrument specialist at Thermo about it, we agreed it wasn’t actually needed and I’ve removed it from all my performance checks.  Apparently it was only included at the request of one customer and only for a very specific application.
 I've only had my iCAPQ for ~ 6 months so am in no way an expert but I’ve PM’d you my email address if you want to send me your tune and performance check files to have a look.

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vgicpms
vgicpms's picture
Hello,

Hello,

I'm new to the forum and have been browsing around.

Your Ratio of the ClO/Co is 16. The spec I believe is 18. As indicted the Co signal is pretty good so you can afford to play with the ratio and improve this. You could try increasing the Cell Gas which would knock down your Signal at Co but may also increase this ratio.

There are also other Tune Parameters which can be adjusted. If needed I can discuss further.

Have you managed to get a hold of Thermo?

Cheers
John
Former Thermo ICPMS Technical Specialist

David Spiteri
David Spiteri's picture
icap Q

HI John,Apologies for getting back after 4 years! seem to have stopped using this forum. Anyway, do you have an e-mail, which we can keep in touch?Thanks

Jacquie Y
Jacquie Y's picture
Failed Autotune

Hello, I've been having a problem with the iCAP's Autotune, and am wondering if anyone else has experience it. At the end of the Autotune, this message appears repeatedly in the Summary section: "Finished status of Dio is reached, but the value of -0.0052785923753671 read from Adc: TorchVertical Position Readback, is not in between the tolerance of 0.2! The autotuning was not successful." Any advice about what might be wrong and/or how to fix it would be greatly appreciated. Thank you! Jacquie

David Spiteri
David Spiteri's picture
Slide valve not opening

HI,After 6 months of one failure to another, we are again back to square one. slide valve not opening! So plasma sequence starts normally, perani pressure ok, expansion valce opens, backing valve ok. As soon as the slide valve goes to open... this fails and switches of plasma!Anyone saw this problem? Would really need help on this.

Sea land
Sea land's picture
iCAP's

Hi David, How do you like ICAPS icpms? We are planing to buy one, but not sure iCAPs or Nexion 1000 yet. Any comments? Thanks.