How to measure blood acetaldehyde levels accurately

Basic questions from students; resources for projects and reports.

4 posts Page 1 of 1
Hi, I was quite amazed and happy to find that there was a website / forum for chromatography and related, I really hope you can help me with something.

I am ill from a very strange but interesting disease in that my body produces endogenous acetaldehyde on its own without any alcohol involvement. You could say I am sort of half-drunk all the time with the strangest of symptoms. It turns you into a complete physical wreck and has quite the influence on the brain too, nothing works as it should any more when you have this. It is a not yet properly researched disease in relationship with the digestive tract, I could tell a whole lot about it but I think I will leave that for now but trust me it is a real and serious illness.

I had my blood tested for endogenous acetaldehyde and the result was that it was a whopping 10 times over the limit. Later when I had managed to make my disease somewhat less I tested again and the acetaldehyde level had dropped considerably but was still to high. Blood samples were very well taken care of and were also tested for ethanol to rule out artificial formation of acetaldehyde as much as possible. Ethanol was below detection point so that is good. Method used was whole-blood gas chromatography at a professional forensics toxicology lab. For my purpose this method was sort of good enough it does not matter that much if there was some margin of error because it was so completely out of the norm. But to compare other people’s levels this method is just a bit to inaccurate and not repeatable enough as far as I know.

There has been very little research into endogenous acetaldehyde blood levels in humans without alcohol involvement and as far as I know also not in people with specific health complaints. The levels are normally very, very low. Some of this research is already quite old, one research paper on PubMed is

“Studies of whole blood-associated acetaldehyde levels in teetotalers.“ ( https://www.ncbi.nlm.nih.gov/pubmed/8216889)

And I wonder how they produced such repeatable low-level results to compare.

My question is :

How would you go about measuring endogenous acetaldehyde blood levels accurately and repeatable with today’s modern equipment and methods ?

People I am really sort of begging for your help here, I know very little about it other than that measuring acetaldehyde in blood is a bit tricky business but it has been done before, and that there are smart persons here on this forum who would know how to do such a thing.

I would like to learn more about a suitable method and in the future find a laboratory willing to do such tests to find people with the same disease as me. Who knows maybe your input could even help lead to something like that happening in the future ? That would be quite something because there are actually many more people out there with the same problem but they are simply unrecognized / undiscovered yet. It is a very interesting medical phenomena. So I really hope you can help me with this I would not know a better place to ask and turn to at this moment.
I'm sorry to read about your problem. I'm sure it's difficult to manage. I've never heard of this one.

I found this article that describes the hoops you have to jump through to analyze for acetaldehyde in whole blood in the presence of ethanol. All of what they do is designed to prevent oxidation (chemically or biochemically) of the ethanol to acetaldehyde during the sample prep and analysis. In your case, you basically haven't got ethanol in your blood so those precautions aren't necessary. The salting of the sample is necessary to get the sensitivity that is required, however. increasing the ionic strength of the medium will drive the soluble AA into the headspace and improve the sensitivity.

The simple headspace-analysis conditions they describe (75 °C for 16 minutes, inject on a wax column) should be all that's required to get accurate AA numbers for your samples. It is easy to separate AA from EtOH with that GC column and the flame detector is very, very sensitive.

Static headspace GC-FID is how I'd detect it if this problem were presented to me as well.

8 µM is right in the middle of the calibrated range described in this paper.

Search "acetaldehyde analysis whole blood application" in google and it's the first thing that came up for me. I pasted the link in earlier but the session "timed out" so I had to change to you searching what I searched. I don't know of a way to share documents.

In their chromatogram there's also this massive material that's coming out unretained. The FID doesn't respond to anything that doesn't burn - i.e., water and CO2. I can't imagine what else could be in whole blood that would elute that early AND respond in an FID.
Thank you for giving it a thought it is much appreciated. I believe you are referring to "An Accurate, Automated, Simultaneous Gas Chromatographic Headspace Measurement of Whole Blood Ethanol and Acetaldehyde for Human In Vivo Studies" https://academic.oup.com/jat/article/21/2/134/684117 and I have read that one too because it is a good one giving quite a lot of information.

With "salting" you mean adding the sodium nitrate that will give better / higher results right ? So that seems necessary good to know.

What you mentioned that they used "75 °C for 16 minutes, inject on a wax column" I have also read in a preview of the book "Gas Chromatography and Mass Spectrometry: A Practical Guide 2nd Edition" about measuring aldehydes so that seems to be used as sort of standard practice I guess then and 1-propanol is the internal standard that would always be used for such a test right ?

In the graphs on the left at the end of the paper they are measuring below 2 μM acetaldehyde at the start of the test and below 1 μM at the end. Hhmm... that looks good that they can measure so low. But then they mention in text in the paper : range 2-80 μm . As far as I can see they did not include baseline measurement before the alcohol test it is such a real pity that they did not include that. (The graph is actually quite interesting otherwise btw in that acetaldehyde levels are already leveling off while the ethanol is still elevated).
But maybe this test is possibly usable for low level endogenous acetaldehyde then.

I have tried to do my homework as much as I am capable of given my limited knowledge about it and have read many an open access paper about measuring acetaldehyde but practically all have to do with alcohol research and I see all kinds of difficult tests that are not necessary because of no ethanol in this case. But the problem is I don't have the knowledge to know what to leave out what is unnecessary and what to keep in when I read about it. And most of them seem not to be able to measure very low levels of acetaldehyde anyway.

But all the other papers that I am interested in, the ones about endogenous acetaldehyde without ethanol ( and there are only a few) are all not open access and you find so little else about it ! So I am asking you people how it would work. And whether it would even be possible to do for the average laboratory out there and that is of course a whole different question all together.

Here is one quite a funny endogenous acetaldehyde paper :
"Quantitative analysis of acetaldehyde in whole blood from human and various animals by gas chromatography" : https://www.sciencedirect.com/science/a ... 4798003909
Well isn't it good to know that the average human has an acetaldehyde level that lies between a hamster and a pig, hmmpff..... They measured 6.17 μmol/ml in human whole blood.

Again I wonder what sort of method did they use ? To even bother mentioning results with 2 decimal point format seems to imply that they can measure these low levels quite accurately.

I have seen a number mentioned of the lowest mean endogenous acetaldehyde concentration in human whole blood as 2.2 ± 1.1 µmol/l. Question is of course what method was used to be able to compare everything. All ideas about measuring endogenous acetaldehyde are welcome !

I will explain some more next time about why accurately measuring endogenous acetaldehyde is so important in this case but it would be too long for now. Instead (and to spark a bit of interest in the topic) I will leave you with the following :

If you go to https://www.youtube.com/watch?v=ImYMRJUAZUc you see this man who can't handle the alcohol very well ( research Asian Flush for this acetaldehyde build-up phenomena). I was as red in the face as him at about three-quarter of the video except I had this practically permanently, day in day out, literally for years... and I would even often flush bright red on top of that as seen in the end of the video. In fact I was often completely red-skinned from head to toe like a fire truck ! I was also sort of drunk-driving, a physical wreck with an incredible amount of symptoms / problems and not to mention the strange things it did with my brain. All without any alcohol involvement, no alcohol necessary for this to happen ! All because of an endogenous acetaldehyde build up in the body in relationship with a digestive tract problem.
That paper we've both quoted describes the hoops you have to jump through to keep the ethanol from oxidizing during sampling so that you don't artificially skew the acetaldehyde measurement. If there is no ethanol present - if I understand you correctly, this is your case - you can't create acetaldehyde during your sampling.

There is no real need to take all of the precautions except for the fact that adding all of that salt will modify the matrix and the partitioning behavior of the acetaldehyde relative to the blood. This method should work for measuring acetaldehyde in whole blood - even when ethanol is not present. Headspace measurements can be very matrix dependent so if you add a bunch of salt to your sample, you have to add a bunch of salt to your standards.

It seems that according to this paper, less than 1-2 µM is considered a low concentration in whole blood. That's pretty good. Since the AA in your blood is large, why do you care about the low end? I thought you just wanted a good way to accurately measure AA in blood. To me, this is it.
4 posts Page 1 of 1

Who is online

In total there are 10 users online :: 0 registered, 0 hidden and 10 guests (based on users active over the past 5 minutes)
Most users ever online was 599 on Tue Sep 18, 2018 9:27 am

Users browsing this forum: No registered users and 10 guests

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry