I have a water sample contaminated with various organic solvents like methanol, ethyl acetate, acetone, formaldehyde, formic acid etc. Which method can be used to find out what all solvents present and also quantity of each solvent.
Hello, if you have suitable GC/MS system i will suggest gas chromatography by the purge-and trap method or equivalent. Have a look at the link or google for "analysis of VOC in water". If that option is not available - depending on the amount of the organics - you could try NMR. Add your water solution of the organics and add a capillary with d6-benzen to shim. With use of internal standard you will be able to quantify and compounds will be easily distinguishable even from 1H-NMR (at least one you list).
https://www.ssi.shimadzu.com/industry/methods/m_8260C.pdf
If you are expecting ketones and aldehydes then I would use 2,4-dinitrophenyl hydrazine (Brady's reagent) to convert these to easy to measure derivatives. Then use HPLC to measure the different amounts of these compounds.
For the the carboxylic acids I would suggest using a weak base ion exchange resin to concentrate them, then use a stronger acid such as lactic acid in methanol / butanol to remove them from the column. Finally convert them into methyl or butyl esters and then do GC with a FID machine.
For the alcohols I would suggest that you could use head space GC
Thank You Maxim V. Galkin, I cant use GC because our GC coloumn was not meant for water based samples. I think by NMR analysis I can proceed.
Thank you Michael Pach
The concentrations of the samples are in ppm level. NMR is available for us.
Thank you Mark Foreman
My samples contains esters, acids and alcohols along with water.
You can detect and identify the organic solvents present in water by GC-MS analysis
GC and Lc-ms are suitable technique for organic solvents. You have to optimise solvent system for your sample and GC conditions. I think for the group of solvents having very nearby boiling points or having much difference in boiling points, temperature programming will give good results
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