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Formic acid quantitation [View Printable]
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Hyder
Group: Member Posts: 3 Joined: May 08, 2007
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Dear All, currently i'm trying to develop a method to quantitate Formic acid, I tried many HPLC conditions, but i didn't find the right method, my limit was 100 ppm. Did some one have an idea or a solution for this problem. thanks. New member.
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| Posted May 08, 2007, 20:02 PM |
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Tony Rook
Group: Member Posts: 581 Joined: Nov 03, 2005
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Here are a couple of references that may help -
Masana Ogata, Tomoko Iwamoto. Enzymatic assay of formic acid and gas chromatography of methanol for urinary biological monitoring of exposure to methanol. International Archives of Occupational and Environmental Health. Volume 62, Number 3 / April, 1990, 227-232.
Summary An enzymatic assay method for the determination of urinary formic acid is described. Formic acid in urine was cleaved to carbon dioxide and water by formic acid dehydrogenase, whereby NAD+ was converted to NADH, which reacted with INT (p-iodonitrotetrazolium violet) in the presence of NAD-diaphorase. The color thus produced was determined at 500 nm. In addition, a simple gas chromatographic method of urinary formic acid is described, in which head space gas of formic acid methylester was applied into the wide bore column. The urinary formic acid concentrations by the enzymatic method agreed well with that by the gas chromatographic method. A simple gas chromatographic method for urinary methanol assay is also described. Acetonitrile was added to an equal volume of urine containing methanol. After centrifugation, the supernatant was injected into gas chromatography (GC). The peaks of urinary methanol and ethanol were separated by GC. Formic acid and methanol in urine of unexposed healthy subjects and workers exposed to methanol were analyzed by the colorimetric and gas chromatographic methods. Geometric mean concentrations of urinary formic acid and methanol in the healthy subjects were 7.82 mg/g creatinine and 1.34 mg/l, respectively. The concentration ratio of formic acid to methanol in the urine of the workers exposed to methanol was calculated to be 3.67 ± 2.10, which agreed with the ratio under a controlled exposure experiment. A slower excretion of formic acid than that of methanol in the urine of a volunteer was also observed.
Jesse C. Rabinowitz, W. E. Pricer. An Enzymatic for the Determination of Formic Acid. J of Biological Chemistry. 1957. 229 (1): 321.
The present paper describes the preparation of a stable extract from lyophilized cells of Clostridium cylindrosporum, which has previously been shown to possess tetrahydrofolic formylase activity (5), and its use in the determination of formic acid according to Reactions 1 and 2. This method provides a sensitive and specific determination of formic acid.
Hope this helps!
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......................... Tony Rook
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| Posted May 09, 2007, 0:04 AM |
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Hyder
Group: Member Posts: 3 Joined: May 08, 2007
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Thank you tony for your help.
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| Posted May 11, 2007, 14:51 PM |
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ryan_girl
Group: Member Posts: 1 Joined: Nov 29, 2007
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dear all,
i try to analysis betain with HPLC. i have found 1 journal, but it is need derivatization. maybe someone could help me to analyze betain from plants without derivatization also the condition of HPLC
thank you[quote]
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| Posted Nov 30, 2007, 1:39 AM |
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Hyder
Group: Member Posts: 3 Joined: May 08, 2007
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| Hyder said: | Dear All, currently i'm trying to develop a method to quantitate Formic acid, I tried many HPLC conditions, but i didn't find the right method, my limit was 100 ppm. Did some one have an idea or a solution for this problem. thanks. New member. |
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| Posted Nov 30, 2007, 13:11 PM |
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mbicking
Group: Member Posts: 26 Joined: Mar 03, 2008
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This is a difficult separation because formic acid is highly water soluble and does not absorb much ultraviolet light. You should try a reverse phase column that is either "aqueous-stable" or a "polar embedded phase." Your mobile phase should be acidified (0.1 % phosphoric acid). Try detection at 210 nm. You may have to try 205 nm to get enough sensitivity. However, at this wavelength, many other compounds also absorb, and you may not be able to see the formic acid among the othe peaks.
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......................... M. K. L. Bicking, Ph.D. ACCTA, Inc.
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| Posted Mar 17, 2008, 16:10 PM |
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huiqi
Group: Member Posts: 9 Joined: Sep 04, 2008
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hi. i'm sorry to use your tag to ask a few questions. hope you don't mind.
i'm currently recovering formic acid from animal's feeds (highly contaminated and dirty) so was thinking of using gc (either ms or fid) instead of LC. the problem is that i only have non-polar column for gc-fid so is it possible for me to derivatise the formic into methyl formate? if it is possible, how can i go about doing that? can i just extract the feed with 2N methanolic potassium hydroxide? or do i have to extract in hexane before derivatising?
and when i run it in gcms. i was not able to seperate the peaks of formic acid from the solvents (i tried hexane and petroleum ether). so it seems that gcms is not possible to analysis formic acid too.
would appreciate the helps from you guys! thanks a lot in advance! =)
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| Posted Sep 10, 2008, 6:27 AM |
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