FT-IR: oxidation/sulfation a basestock indicator?

[Extreme-Duty]

Hello,

the following might have been asked before, but I cannot really find anything about it on this website. If somebody knows a thread, please give me a link.

Synthetic oils happen to show high oxidation and sulfation numbers in the IR test.

Does that really prove that PAO, esters or other specific ingredients are present in the oil?

Will some labs report these numbers in relation to the values of the virgin oil they have in their database?

For example: A used oil sample shows the lab an oxidation of 130 Abs/cm. Their database tells them that this oil has 100 Abs/cm in it's unused form.

What will the lab write in the UOA report: 100 or 30 Abs/cm?

Thanks in advance for chiming in.

E.D.

 

[Extreme-Duty]

Come on, don't let my thread fall behind!

Should I have posted it in another forum?

If so, please move it, moderators. Thanks.

 

[Eddie]

Ask the laboratories doing the analysis. You should get the best answer from the lab.

 

[bruce381]

""esters or other specific ingredients are present in the oil?""

Yes

""Will some labs report these numbers in relation to the values of the virgin oil they have in their database?""

Ask them all labs are different and even if they have a data point it may not be the same oil as yours since oils will/do differ in base stocks and addtives due to blend plant locatiomn or area answell as formula changes that oil blender make but will not tell you.

For FTIR always send a virgin sample of the exact oil for comparisons otherwise you will get a answer that has high oxidation but it is not perhaps so, just the esters showing in the oxidation range.
bruce

 

[MolaKule]

Quote:
Synthetic oils happen to show high oxidation and sulfation numbers in the IR test.

Does that really prove that PAO, esters or other specific ingredients are present in the oil?

Will some labs report these numbers in relation to the values of the virgin oil they have in their database?


1. Most labs check only for the standard values of wear and additive elements, TBN, TAN, nitration, viscosities, and flash points, and trending so most labs are only interested in the above, not the makeup of base oils.

2. Only a few sophistcated labs using advanced FTIR and adsorption analysis would or could report base oil types and ratios.

3. Many of the newer additives will show elevated oxidation without having esters present.

4. Neither VOA's nor MSDS will show a total formulation. For example, many of the newer AW non-hazardous, non-organometallic agents will NOT show up in $50 analyses.

 

[Extreme-Duty]

Thank you all three,

I asked this because I read so many different things. A German lab, for example, states that its FT-IR oxidation/sulfation is reported relatively to its database. It's hard to believe and I do not like it.

Also, there is a thread on this website where it is said that the given Amsoil product shows a high oxidation reading because of the PAO. I thought PAO bonds do not affect the FT-IR oxidation.

Finally, I can ask the other way around. Will a low FT-IR oxidation reading of 15-20 Abs/cm with a PAO/ester oil automatically "reveal" a low ester content?

One ester does not "look" or absorb like another.

Which components will cause a high IR sulfation?

Quote:


4. Neither VOA's nor MSDS will show a total formulation. For example, many of the newer AW non-hazardous, non-organometallic agents will NOT show up in $50 analyses.


Will we see alternatives to the ICP to detect these modern additives in future UOA?

 

[TeeDub]

If the oxidation level and the change in viscosity don't jive, you can guess there's some type of ester being used that has a wavenumber similar to the Ox peak - as I recall that's @ 1835 cm-1.

I'm guessing the high sulfation is from a sulfated ester of some sort, since we now have the 15 ppm, ULSD fuel on the US.

Oil Analyzers Inc. keeps the baseline FTIR scans for Amsoil, so this isn't an issue with their UOA's.

 

[MolaKule]

Quote:
A German lab, for example, states that its FT-IR oxidation/sulfation is reported relatively to its database. It's hard to believe and I do not like it.


Not sure what you mean by the last sentence. And I am not sure what the German lab is saying exactly; relative to what? So it compares oxidation and sulfation of clean oil to used oil?

Any number of additives could contribute to sulfation levels, including sulferized esters as FM's or the detergent calcium sulfonate, etc.

 

[Extreme-Duty]

Originally Posted By: MolaKule
Quote:
A German lab, for example, states that its FT-IR oxidation/sulfation is reported relatively to its database. It's hard to believe and I do not like it.


Not sure what you mean by the last sentence. And I am not sure what the German lab is saying exactly; relative to what? So it compares oxidation and sulfation of clean oil to used oil?



That's what I was about to say. You should know that I am dealing with three different languages, but I am not perfect in any of them.

I can't say whether they report or just interpret comparing "peaks" of the used and virgin oil. It's written in a way that it will leave you in doubt.

Their website:www.wearcheck.de.

Sorry, the English version does not give you a detailed description of their FT-IR testing.

I am going to ask what's going on with them.

However, the German FT-IR decription says they have more than 1000 virgin oils in their database. Therefore, a virgin oil sample is usually not required from the customer.

The test device is a "Bio-Rad, Boston", which is connected to this reference/virgin oil database. If they do not tell it which reference oil to choose, it will automatically search the database to find the virgin IR-profile that "matches" the sample best.

That might sound odd, but that's what I gather. I'm sorry Mola.

 

[MolaKule]

No Problem Extreme.

Any good lab will have a database of virgin oils to compare to used oils in order to subtract wear metals or to analyze additive changes.

For example, if the virgin oil shows an Fe of 2 ppm of ferrous material (which could be from the anti-oxidant or an AW), the lab subtracts that. Say a UOA which might show 10 ppm. This would mean the Ferrous material from wear was actually 8 ppm.

 

[Extreme-Duty]

To follow up on this, Wearcheck confirmed they use the reference oil to determine and interpret the UOs FT-IR results, saying this is very common. Further, they mention that there are IR methodes that are "getting along" without a reference oil. I don't know about their ICP, I didn't ask though.

As Bruce pointed out, these databases do not really help if "blender integrity" isn't guaranteed.

So, if an oil claimed to be Gr. IV/V shows low oxidation in a UOA, it might be because the lab is aware of the virgin oils IR spectrum. Do I get this right?