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::aflatoxins

Posted: Thu Nov 30, 2006 8:33 am
by n-cute
Hi All,

I have question to all of You :)
How many of You have some experience in aflatoxin analysis?

Posted: Thu Nov 30, 2006 11:11 am
by Peter Apps
That depends on why you are asking !

Posted: Thu Nov 30, 2006 12:06 pm
by n-cute
HPLC food analysis with post column derivatisation (I use PBPB as reagent), aflatoxins B and G, sample preparation using IA columns, fluorescence detector, mobile phase: water/acetonitrile/methanol.

Posted: Thu Nov 30, 2006 12:09 pm
by n-cute
...and I am just curious how many people is doing it in everyday work.

Posted: Thu Nov 30, 2006 4:46 pm
by Mark Tracy
Well, 20 years ago I worked in a veterinary toxicology lab. I did the occasional aflatoxin assay. Then I worked for Pickering Laboratories who sell the post-column gear for that analysis. I try not to do it anymore if I can help it.

Posted: Fri Dec 01, 2006 7:44 am
by n-cute
Well, 20 years ago I worked in a veterinary toxicology lab. I did the occasional aflatoxin assay. Then I worked for Pickering Laboratories who sell the post-column gear for that analysis. I try not to do it anymore if I can help it.
What about aflatoxins toxicity, what kind of safety precautions did You take? I am performing that analysis for few weeks and, hmmm... I'am little bit affraid of its harmhul properties.

Posted: Fri Dec 01, 2006 5:15 pm
by jto
Hi. Great to hear that someone else is out there looking at aflatoxin. What is your matrix? I analyze corn samples for aflatoxins on a daily basis using post column derivitization. Easy, easy method, run time per sample 12min. If you are interested, I can send you more info. Just really busy right now. Would love to keep in touch. What other mycotoxins do you analyze??

Posted: Sat Dec 02, 2006 12:11 am
by n-cute
Af B1 B2 G1 G2 and Ochratoxin A. About my matrix, hmmm... i've started with figs and peanuts. :)
if you want to be in touch:

enkkidu@gazeta.pl

regards

n-cute

Posted: Sat Dec 02, 2006 1:46 am
by sfe-co2
I recall Mark Tracy mentioning a small application note on the Dionex site (C18 column, UV detection....no derivitization) before. I printed it for a friend some months ago. However, I tried the same using my home computer through the Mozilla Firefox browser) and was unsuccessful....chromatogram did not print. I could see it on screen....just wouldn't print. I think it's either my browser or my printer driver.

Aflatoxins have been implicated as potential carcinogens, so please take great care. I have yet to do the HPLC anaysis to date, but have seen labs running it during visiting tours while accompanying Dr. Alice NJ Lee.

Dr. Lee is an expert on the ELISA technique, and have used it as a high-throughput screening tool for, say, peanut samples from different countries. In all cases, quantification is confirmed with HPLC.

Hope the above helps.

Posted: Mon Dec 04, 2006 11:31 pm
by Mark Tracy
There is an aflatoxin chromatogram on the Dionex website (http://www1.dionex.com/en-us/acclaim_li ... 28431.html), but you need Flash to see it, and Firefox works lots better than IE. (I can't get a straight answer why.) I did it to demonstrate the column performance. At the time, I didn't have a fluorescence detector, so I suffered with the lousy detection limits of the UV. In protic solvents (MeOH, H2O) the native fluorescence of B1 and G1 are significantly quenched. The derivitization methods, pre-column or post-column, saturate the double bond that has the negative interaction with solvents. If you do normal-phase HPLC with anhydrous solvents, you don't need any derivatization.

When I worked at the vet-tox lab, we pre-screened with ELISA cards, and only geared up for HPLC on hot samples.

For making the standards, I trust the vendor (usually Sigma) to put the stated amount of aflatoxin in the vial. Since the vials have septum caps, I inject the solvent directly into the vial with a syringe, and withdraw it the same way. It's not class-A quantitative technique, but it's good enough for me.

If you spill aflatoxin, you can detoxify it with sodium hypochlorite, better known as Clorox laundry bleach. At least that's what my counterparts over at environmental tox did.

Finally, check out Romer Labs (www.romerlabs.com); they are the specialists in mycotoxin analysis.

Posted: Tue Dec 05, 2006 8:45 am
by Parsival
You might also have a look into www.mycotoxins.org - This website gives detailed information on any mycotoxins - ranging from occurrence, toxicities to analytical methods used.

Posted: Tue Dec 05, 2006 10:09 am
by n-cute
Thanks to ALL for your Help and advices :)

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