chemrox
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formaldehyde contamination
I have a client that provides trailers to a federal agency. He built some of these with some plywood he got from China. The agency tested the wood
for formaldehyde and came up with lots of the stuff. Technically, the issues would be OSHA and would be how much is in the air inside the trailer.
He wants me to core the new plywood he just got to document its free of formaldehye. No problem there. What I wanted advice on is what would be the
best way to test the atmosphere inside one of his rigs to quantify the stuff? Is there a portable GC one could rent? I couldn't find one that
looked like it would detect anything that polar.
I know I can get carbon blocks like the ones that are used for radon testing but haven't a clue as to their efficacy. I can only ask the lab that
would test them and I'm affraid they will only give me the up side.
I'm thinking I could pump the air sample through a solution of bisulfite and collect the precipitate and weigh it versus the time x rate=volume. I'd
like feedback on that approach. I'm affraid the pumping rate is going to be too hard to measure and control.
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BromicAcid
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I have some experience with DCM testing. In my experience in that area, with respect to OSHA, the DCM badge as it is called, is worn for 8 hours
simulating normal work. Because the badges and subsequent testing is expensive usually they are utilized to monitor sequences of steps or situations
that put the workers at the highest risk of exposure. Are the trailers going to be open or have ventilation while people are working in them? These
badges are just activated carbon but you send them to the same testing company you purchase them from and they extract the organic components and
analyze them then you can tell if you pass the time weighted average for the 8 hour work day. It's not terribly expensive, but you don't want to have
to test more times than necessary.
Seriously, if you are messing with OSHA stuff, this sort of route provides accurate and certified information that you can fall back on.
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Ozone
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Senior 'Rox,
Check out EPA method 8315 (I think I may have posted it on the site already). The method involves HPLC quantification of various aldehydes as DNPH
(2,4-dinitrophenyhydrazine) derivatives.
For air testing, this would involve pulling air (with a calibrated flow over time) through either a) a DNPH impregnated silica gel filled tube or b)
midget impinger loaded with DNPH, acetate buffer (pH 5) and a co-solvent. The tube or impinger would be extracted with dichloromethane and
concentrated.
These will be run via reverse phase (ODS) against an Acetonitrile:water gradient with, IIRC, detection as absorbance at 360nm.
PLease see also, IIRC, EPA 18 (maybe NIOSH) and also, the quick test using conc. H2SO4 and chromotropic acid.
FEMA trailers? i'm from crawfish-land, so this sounds familiar. Let me know if you need the method.
Cheers,
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
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chemrox
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| Quote: |
Seriously, if you are messing with OSHA stuff, this sort of route provides accurate and certified information that you can fall back on.
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And, ultimately that's what's needed.
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chemrox
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| Quote: |
PLease see also, IIRC, EPA 18 (maybe NIOSH) and also, the quick test using conc. H2SO4 and chromotropic acid. |
I will shop out the 8315 for the core samples but I would realy like to look at the above technique. Appreciated greatly, thanks!
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Endo
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Formaldehyde Assay
Formaldehyde from solids or liquids can also be done by derivitizing using the Hantz? reaction with Acetyl Acetone, Ammonium acetate buffer. I have
used this combination for analysis using a post column reactor with fluorescence detection. Extraction and standard prep using ACN or water as the
solvent.
It is less explosive than DNPH.
Endo
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chemrox
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I wish I had that kind of equipment but we're not set up to do analytical work except real basic stuff. For some things I could do quantitative IR
but I don't know where to set my error bars for this agent (or any other as yet). If you want the work we could ship them to you for say, $200 a pop?
(Polverone, is it cool to do business on the forum?)
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