Polaris Q (GCMS)

[Rganga]

Hi I have a PolarisQ and I am new using this equipement.
The Polaris Q was shut down for 3 months. I tried to start working and after 4 days of running, the fore pressure still around 55-60 which is higher than the recommended pressure by the manufacturer. I run the autotune and it failed, the report says that Resej amp failed and Mass, injection RF, waveform and leak check NOT RUN.
Someone could tell me please where the problem is and what should I do?
Thank you very much

R.Ganga

[nkg]

the fore pressure could just be down to what column / flow you are using. as the system has been off I would recommend that you remove the column from the ms and check the vacuum level with it blanked off. once this has been done, do an air/water scan (after a couple of hours at least, if not overnight) from the tune page and see what the levels of 18 / 28 are and also the ion time of the scan. the ion time should be at maximum (25mS) or very close. if this is ok then do an autotune, best thing to do is only select one option at a time, this will then store the 'good' completed part.

before you did an autotune did you check the response of the fc43 in a full scan (50-650), if so what sort of levels were you getting for the TIC?
a few queries
can you see the baseline easily at mass 100?
did you clean the system before you started with it being off for 3 months? if not it might just need a good clean or a bake out overnight.

[Rganga]

Thank you very much for your response.
The system is new, but It was bought 2 years ago, we started to use only 6 months ago and the last 3 months it was shut down, because I was on training in another lab on techniques using this equipment. I did not clean the system after this time. I am new on Mass world. How can I clean the system?
I checked the response of fc43 in a full scan (50-650), the levels of TIC are around 5.9 +3, and the ion time is 25.0 ms.
I can see the baseline at mass 100.
But when I do Air/water, I can’t see all the peaks at the same time, I see only one by one. The ion time is 25ms but the TIC is only 1 +0.
Thank you very much again
Rachid

[nkg]

At a guess, I would imagine that the default tune has been loaded. this would have reset the multiplier to a low value and would explain why you are seeing only 5 +3 for fc43 and 1 +0 for air/water. In an ideal situation you should get 25mS for air/water as this would indicate a leak free system as the trap is filling to maximum for the scan. for fc 43 you should be getting in the region of 1+6 / 1+7 depending on the system.

To start with, either try just doing the multiplier gain on its own from the autotune, or from the tune page select 'tune/manual, then in the general tab increase the multiplier until you see fc43 response in the tune page (50-650) in the area of 1+6/ 1+7. Once you are in this sort of area then you can check the air/water response and you should also be able to get somewhere with the autotune routine. Best thing to do would be select everything apart from multiplier gain and see if the instrument can sort itself out

[Rganga]

Thank you very much for your answer.
You are right, I did an autotune with only the multiplier gain option and it failed. I increased the multiplier voltage to 1400, no way? The same problem happened and the autotune fails at log(Gain) vc Multipier step. And the message is: % Gain Error vc Setpoint.
The forepressure is still high (53 m Torr) and it is reaching 59 sometimes.
I did a water/air test and still too low 3 +0.
What do you think I should do? Maybe waiting more time to give sufficient time to outgas (pump out), because the system was shutdown for long time? How can I remove dust on dynode or multiplier?

Thank you very much for your time and your wonderful assistance.

RG

[nkg]

When you had the multiplier set at 1400V was the TIC for fc43 at around 1+6?, if not increase the multiplier until this is achieved. Dont worry too much about the voltage on the multiplier if you have to increase it to see a response. If this is now correct then do an autotune selecting everything except the multiplier. Just reread your second post, what happened with the system for the first 18months? was it installed and then turned off? Also worth checking is what ion volume you have in the system, does your ms have a vacuum interlock on the front? if not you will have to vent the system to find out. As you are concerned about the vacuum level have you blanked the ms off to eliminate any issues from the gc / column? if not this might be a good time do do so as then you are concentrating on the ms, not worrying about any other possible issues coming from elsewhere. Whilst we are still trying to sort out any problems, have you ran the diagnostics from the tune page? if so are they all passing? to get more detailed information click on each test option individually as this will bring up another screen with the test being carried out. If you just click on run selected tests then you will only get a pass / fail at the side of each test option

what column is installed and at what flow are you running?

[Rganga]

Our system bought 2 years ago, it was installed 1 year ago and was turned off for the majority of time. Only 3 months We started to put techniques on and work with recently.
In full scan of FC43. The main peak is 132.5. 69 is almost inexistent it appears (less than 2%) and disappears (most of the time). The other peaks are 101.3 (2%), 170.9 (6%), 165.9 (4%). No trace of 264, 414 or 502. Today after few tunes trying different options it failed again.
The filament is new. I still have +0 for air/water.
Increasing the multiplier voltage increased slightly the Fc43 TIC up to +4, but more than 1400 decreased again TIC value to +3.
The column I am using is TR-5ms SQC 30*0.25mm ID* 0.25um. the flow I am using is 1.
Our system does not have a vacum interlock on the front.
I run 2 diagnostic tests now and the high mass noise failed 2 successive times.
What that means, It seems that there is a problem to detect the high mass.
Thank you very much
Rachid

[nkg]

Hi Rachid,

I would think that it is time to vent the system and have a check inside. I would give the ion volume / source / lens and trap a clean. this is documented in the hardware manual. The manuals for this system should either be on the cd that you got with it, or try browsing to c:\xcalibur and see if you can find a manuals folder in there somewhere. you should find a 'pq hardware manual 120010 rev b.pdf ( or greater)

with the analyser lid off and the trap assy removed make sure the housing is clean, you can also blow it out with a dry inert gas if this is easier.

This is what I would try first and then at least you know you have a good starting point and can rule out contamination of the ms.

Have you had any results of the system in the last 3 months?

Is this the same column that has always been installed or is it a new type, the reason I ask is that if it has just been installed and not evaluated then the gc could be providing what flow it thinks is right for the previous column and you might actually be getting something completely different.

when you are re-assembling the ms make sure that you clean the analyser o-ring and the analysyer lid so that there is no bits of dust etc on them. make sure that when you slide the trap assy back in to the instrument that the centre pin makes good contact with the centre ring of the trap. there is a small groove that the pin sits in.
make sure that when you re-assemble the source assy the ion volume sits in correctly and is not too loose.

remove the column from the ms and fit a blanking nut to the transfer line

you can put the column back in the system in no time at all when you have the ms working.

could you let me know what the ms source settings are? temperature / emission / lens values etc



best of luck

[Rganga]

Thank you very much for your assistance,
Yes I decided to vent the system and give a clean to lenses, ion and detector, but I have never done this maintenance, I don’t feel secure to do it alone, so I asked for an engineer to come and at least I will do it with him this time and learn in order to do it by myself in the future.
The value of TIC are still by far very low comparing to the recommended values. And the detector diagnostic still failing at High Mass Noise step.
We never had results from this equipment, it is new but it was off for long time we did only some initial trials by injecting some fatty acids methyl esther. But we bought it mainly to do PCB and PBDEs analysis and if we are lucky we plan to try some dioxins. I was on training learning these techniques and I am just back to start setting up the techniques. But I found this problems.
We did not changed the column or anything else, as it was installed the first time.
The ms source setting is 200ºC, lens1: -25.1, lense3: -25.1, electron lens:15. Trap ofsset: -7. Electron energy: -71.2, emission current: 250-260 (setpoint at 250).
Thanks again, I am really desperado; I am waiting for the engineer and want to start with my samples soon.
Thanks