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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: ridkil on April 22, 2011, 04:58:07 AM

Title: Ph testing of Chloroform
Post by: ridkil on April 22, 2011, 04:58:07 AM
Hi guys,

we have had some issues with chloroform recently and are trying to develop a reliable way of measuring pH, the level we are looking at is below 1ppm and so titration does not seem like an option, the methods we have tried are too subjective with a difference of just a single drop differentiating what we expect to be a "good" batch and a "bad" batch. currently we are examining extracting the HCL from the chloroform into water and then measuring the resulting pH, is there a reliable, robust method of doing this?? this issue is driving me nuts!!!  ::)
Title: Re: Ph testing of Chloroform
Post by: enahs on April 22, 2011, 01:31:51 PM
I am not sure what you are saying you are doing, you are trying to measure the pH of the Chloroform?
Title: Re: Ph testing of Chloroform
Post by: ridkil on April 26, 2011, 04:08:55 AM
yes, we are trying to measure pH of this polar solvent by extracting the HCL content of the chloroform into water and then measuring the water, as described above, is this the best approach or is there a better way of doing this??? thanks again!
Title: Re: Ph testing of Chloroform
Post by: AWK on April 26, 2011, 04:53:23 AM
HCl is a rather weak acid in chloroform, and a strong one in water, so this comparison is rather worthless. Measuring content of HCl by titration of water extract will be more reliable.