Question

I have a mixture of Ethanol / Methanol and Butanol that I wanted to assay. Would it be possible to develop a spectrophotometeric method for this? (Currently a GC is being used)

The analysis does not have to be too accurate. 1% accuracy would be fine. However the interest is in a rapid analysis and hence something like spectrophotometric is of interest.

Any thoughts?

Answer 1

While spectrophotometric methods for alcohol mixtures face challenges, LC-MS or LC-MS/MS could provide high specificity for a rapid analysis, surpassing the current GC methods.

Step-by-step explanation:

Developing a spectrophotometric method for the assay of a mixture containing ethanol, methanol, and butanol is a challenging task due to the overlapping absorption spectra of these alcohols. However, high specificity and sensitivity can be achieved using liquid chromatography-mass spectrometry (LC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS), which allow for the separation and precise quantification of similar compounds.

An example of a successful implementation is a mobile phase consisting of water with 0.1% formic acid and methanol in a ratio of 85:15, v/v, with an ESI source set in positive ionization mode and quantification by MRM. This approach can serve as an efficient and rapid analysis technique compared to traditional methods such as gas chromatography (GC), which is currently being used.