5977B: Etune and BFB

[Ostravaczech]

Hi all,

our VOA chemist quit and so I have been thrown into the VOC lab intermittently. Since I have NO experience with 5977B EIXTR and only a week before the chemist is gone, I need as much guidance as possible. We run EPA 524.2 on 8890 / 5977B combo with OI concentrator / autosampler (4470, if I recall).

Firstly, I think I need to vent the MS tomorrow to see the column installation into the source since it looks like it was installed incorrectly by the chemist (who says it is protruding 2 mm beyond the ceramic tip). I was seeing strange ramp patterns for REP, IF, EL and emission current.

Secondly, how do I tune the mass spec using Etune to pass BFB for 524.2? I know Agilent recommends their BFB_Atune but the sensitivity compared to Etune is like 50X less when I look at the fluorobenzene response (I know I can bump up the gain to get the response where I want it). Can somebody chime in with their procedure on how to Etune for the volatiles?

I come with years of experience on 5975C, 7000C EIEX (for NDMA), Shimadzu QP2020NX (for EPA 525) and some old IT MS (Thermo). Have not been in the VOC lab in years.

Any guidance will be greatly appreciated.

Cheers,
Ivo.

[70 eV]

Why are you running a high mass tune for a low mass method? Is your normal wheelhouse semi volatiles?

[Ostravaczech]

Why are you running a high mass tune for a low mass method? Is your normal wheelhouse semi volatiles?

I come from semi vol lab with many years of experience (GCMSMS, LCMSMS, GCMS). Just last week I was thrown in the VOA lab with a brand new 5977B for volatiles in drinking water by EPA 524. I was asking about ETUNE to pass BFB criteria listed in EPA 524. I know that Agilent has BFB_Atune macro for BFB tune but I was wondering if there are people out there who use ETUNE for EPA 524. Maybe they have list of parameters (REP, IF, EL, emission, etc) that they would recommend.

[70 eV]

I would just run the bfb atune. 219 at 130-140% of 69 is kinda nuts for volatiles. Xylenes quant on 106, HCBD, TCB, and naphthalene are pretty much your only analytes that get that heavy. Agilent’s whole spiel about eitune was how it was great for high mass applications. Acetone isn’t high mass

[James_Ball]

I would just run the bfb atune. 219 at 130-140% of 69 is kinda nuts for volatiles. Xylenes quant on 106, HCBD, TCB, and naphthalene are pretty much your only analytes that get that heavy. Agilent’s whole spiel about eitune was how it was great for high mass applications. Acetone isn’t high mass

True, but it is the only autotune that uses the source in extraction mode. It would be the base that you start with to then tune manually to meet BFB criteria using the higher sensitivity mode.

We do it here, and it is similar to starting with an Atune and manually adjusting to meet BFB. When using Extraction mode you really don't do much with the repeller like you do in normal EI mode. Let it tune automatically, shoot a BFB and see how it needs to be changed. I first look at a ramp of each lens (minus the Entrance Lens Offset) and make adjustments to those to bring 131 and 219 versus 69 to levels that will get your 95 and 174 in line as you want 174 down around 85% of 95. Then look at 131 and 219 versus 50 if you are having problems getting 50 above lower limit. Lastly I will use variable on the Entrance Lens Offset to tweak any further as needed.

To be honest, we only use Extraction mode when doing 524.3 SIM for EDB and DBCP at the method 504 detection levels. If you just need THM or full list VOC down to 0.5ppb you are better off using the standard mode BFB tune, otherwise you will be cutting your upper range severely as even 5ml purge at 50ppb can top out the peaks for the later analytes, maybe even at a lower concentration. But Extraction works wonders when you are pushing down to 0.01ppb for EDB.

[70 eV]

To be honest, we only use Extraction mode when doing 524.3 SIM for EDB and DBCP at the method 504 detection levels. If you just need THM or full list VOC down to 0.5ppb you are better off using the standard mode BFB tune, otherwise you will be cutting your upper range severely as even 5ml purge at 50ppb can top out the peaks for the later analytes, maybe even at a lower concentration. But Extraction works wonders when you are pushing down to 0.01ppb for EDB.

Are you hitting 10 ppt with your normal 524 full list method? I wrote it off thinking the dwell times would have to be too long. We're still running it via 504. 6 mm extractor lens?

[Ostravaczech]

I would just run the bfb atune. 219 at 130-140% of 69 is kinda nuts for volatiles. Xylenes quant on 106, HCBD, TCB, and naphthalene are pretty much your only analytes that get that heavy. Agilent’s whole spiel about eitune was how it was great for high mass applications. Acetone isn’t high mass

True, but it is the only autotune that uses the source in extraction mode. It would be the base that you start with to then tune manually to meet BFB criteria using the higher sensitivity mode.

We do it here, and it is similar to starting with an Atune and manually adjusting to meet BFB. When using Extraction mode you really don't do much with the repeller like you do in normal EI mode. Let it tune automatically, shoot a BFB and see how it needs to be changed. I first look at a ramp of each lens (minus the Entrance Lens Offset) and make adjustments to those to bring 131 and 219 versus 69 to levels that will get your 95 and 174 in line as you want 174 down around 85% of 95. Then look at 131 and 219 versus 50 if you are having problems getting 50 above lower limit. Lastly I will use variable on the Entrance Lens Offset to tweak any further as needed.

To be honest, we only use Extraction mode when doing 524.3 SIM for EDB and DBCP at the method 504 detection levels. If you just need THM or full list VOC down to 0.5ppb you are better off using the standard mode BFB tune, otherwise you will be cutting your upper range severely as even 5ml purge at 50ppb can top out the peaks for the later analytes, maybe even at a lower concentration. But Extraction works wonders when you are pushing down to 0.01ppb for EDB.

Thank you, James. I noticed there are 3 options with 5977B: Atune, Etune and BFB_tune. So, what you are suggesting is run the Atune and tweak it? Skip the Etune altogether? While running Etune, the profile scans for the lenses and repeller were bizarre looking last week, not smooth at all as I am used to seeing on my 7000 QQQ. Also, after having run the BFB_tune, I noticed that the EM is around 20 uA so I assume that the tune routine optimizes that parameter as well? I have not had any time to look closely at the operator’s manually yet so at this point I am gathering info from the chemist.

We have been running EPA 524.2 and we need to see down to 0.5 for most (with the exception of CM, BM and CE which have MRL set at 1). First thing I need to do is vent the MS to look at the TL installation and possibly pull it back where it needs to be since the chemist says the TL is protruding 2 mm pass the ceramic tip.

[James_Ball]

I would just run the bfb atune. 219 at 130-140% of 69 is kinda nuts for volatiles. Xylenes quant on 106, HCBD, TCB, and naphthalene are pretty much your only analytes that get that heavy. Agilent’s whole spiel about eitune was how it was great for high mass applications. Acetone isn’t high mass

True, but it is the only autotune that uses the source in extraction mode. It would be the base that you start with to then tune manually to meet BFB criteria using the higher sensitivity mode.

We do it here, and it is similar to starting with an Atune and manually adjusting to meet BFB. When using Extraction mode you really don't do much with the repeller like you do in normal EI mode. Let it tune automatically, shoot a BFB and see how it needs to be changed. I first look at a ramp of each lens (minus the Entrance Lens Offset) and make adjustments to those to bring 131 and 219 versus 69 to levels that will get your 95 and 174 in line as you want 174 down around 85% of 95. Then look at 131 and 219 versus 50 if you are having problems getting 50 above lower limit. Lastly I will use variable on the Entrance Lens Offset to tweak any further as needed.

To be honest, we only use Extraction mode when doing 524.3 SIM for EDB and DBCP at the method 504 detection levels. If you just need THM or full list VOC down to 0.5ppb you are better off using the standard mode BFB tune, otherwise you will be cutting your upper range severely as even 5ml purge at 50ppb can top out the peaks for the later analytes, maybe even at a lower concentration. But Extraction works wonders when you are pushing down to 0.01ppb for EDB.

Thank you, James. I noticed there are 3 options with 5977B: Atune, Etune and BFB_tune. So, what you are suggesting is run the Atune and tweak it? Skip the Etune altogether? While running Etune, the profile scans for the lenses and repeller were bizarre looking last week, not smooth at all as I am used to seeing on my 7000 QQQ. Also, after having run the BFB_tune, I noticed that the EM is around 20 uA so I assume that the tune routine optimizes that parameter as well? I have not had any time to look closely at the operator’s manually yet so at this point I am gathering info from the chemist.

We have been running EPA 524.2 and we need to see down to 0.5 for most (with the exception of CM, BM and CE which have MRL set at 1). First thing I need to do is vent the MS to look at the TL installation and possibly pull it back where it needs to be since the chemist says the TL is protruding 2 mm pass the ceramic tip.

For the EDB/DBCP we only run those analytes with the internal and surrogates for 524.3 all in SIM and down to 10ppt. For full list we run 524.2 as normal. The difference is the check box in the tune for High Sensitivity which runs it in extractor mode. If that box is off, it runs it just like a normal EI source same as in the 5975. When in Extractor mode the ramps do look different, but ours are normally smooth, just more flat at the top for most of the lenses.

For 524.2 we just run the BFB autotune, then tweak if needed. If you like manually tuning you can use Atune as a starting point then move the lenses to get to where you need. Back on the 5971/72 the BFB algorithm was not always successful, it was better with the 5973/73, but seems to be much better with the 5977 under Mass Hunter. When I started out, it was on the 5970 which only had Atune and anything else was done manually, so that is how I still do it most of the time.

Running in high sensitivity Extractor mode will give you more sensitivity and less background, but also reduces your linear range some, so if you are looking for the THMs it can lead to more dilutions to keep them inside the calibration curve. We use the standard BFB tune ran as a standard source for the full list and THMs and still see 0.5ppb easy and can calibrate up to above 100ppb.

[Ostravaczech]

True, but it is the only autotune that uses the source in extraction mode. It would be the base that you start with to then tune manually to meet BFB criteria using the higher sensitivity mode.

We do it here, and it is similar to starting with an Atune and manually adjusting to meet BFB. When using Extraction mode you really don't do much with the repeller like you do in normal EI mode. Let it tune automatically, shoot a BFB and see how it needs to be changed. I first look at a ramp of each lens (minus the Entrance Lens Offset) and make adjustments to those to bring 131 and 219 versus 69 to levels that will get your 95 and 174 in line as you want 174 down around 85% of 95. Then look at 131 and 219 versus 50 if you are having problems getting 50 above lower limit. Lastly I will use variable on the Entrance Lens Offset to tweak any further as needed.

To be honest, we only use Extraction mode when doing 524.3 SIM for EDB and DBCP at the method 504 detection levels. If you just need THM or full list VOC down to 0.5ppb you are better off using the standard mode BFB tune, otherwise you will be cutting your upper range severely as even 5ml purge at 50ppb can top out the peaks for the later analytes, maybe even at a lower concentration. But Extraction works wonders when you are pushing down to 0.01ppb for EDB.

Thank you, James. I noticed there are 3 options with 5977B: Atune, Etune and BFB_tune. So, what you are suggesting is run the Atune and tweak it? Skip the Etune altogether? While running Etune, the profile scans for the lenses and repeller were bizarre looking last week, not smooth at all as I am used to seeing on my 7000 QQQ. Also, after having run the BFB_tune, I noticed that the EM is around 20 uA so I assume that the tune routine optimizes that parameter as well? I have not had any time to look closely at the operator’s manually yet so at this point I am gathering info from the chemist.

We have been running EPA 524.2 and we need to see down to 0.5 for most (with the exception of CM, BM and CE which have MRL set at 1). First thing I need to do is vent the MS to look at the TL installation and possibly pull it back where it needs to be since the chemist says the TL is protruding 2 mm pass the ceramic tip.

For the EDB/DBCP we only run those analytes with the internal and surrogates for 524.3 all in SIM and down to 10ppt. For full list we run 524.2 as normal. The difference is the check box in the tune for High Sensitivity which runs it in extractor mode. If that box is off, it runs it just like a normal EI source same as in the 5975. When in Extractor mode the ramps do look different, but ours are normally smooth, just more flat at the top for most of the lenses.

For 524.2 we just run the BFB autotune, then tweak if needed. If you like manually tuning you can use Atune as a starting point then move the lenses to get to where you need. Back on the 5971/72 the BFB algorithm was not always successful, it was better with the 5973/73, but seems to be much better with the 5977 under Mass Hunter. When I started out, it was on the 5970 which only had Atune and anything else was done manually, so that is how I still do it most of the time.

Running in high sensitivity Extractor mode will give you more sensitivity and less background, but also reduces your linear range some, so if you are looking for the THMs it can lead to more dilutions to keep them inside the calibration curve. We use the standard BFB tune ran as a standard source for the full list and THMs and still see 0.5ppb easy and can calibrate up to above 100ppb.

Thanks again, I do appreciate your input. It will be a very busy week for me in the VOC lab! What brand of P&T do you have in the lab? We have several OI 4760, they work OK but not great.

[James_Ball]

We use EST Encon/Centurion P&T and autosampler now. We had one OI back 30 years ago and it worked well, and for many years back then we used the Tekmar 2000/2016 then replaced the 2016 with the Archon autosampler. After that it was all EST. They always give us good service any time we need it, and will work with us over the phone or emails to fix things if possible.