Methyl Iodide

Application Summary

Analysis Point Analyte Suitable Analyzer
Acetylation Reaction Methyl Iodide OMA-300 UV-Vis Analyzer


Acetic anhydride is a crucial chemical intermediate used for acetylation reactions. It is commonly used in the manufacture of everyday products like aspirin or photographic film. As a result of this demand, over one million tons of this chemical is produced in the United States alone every year.

The carbonylation of methyl acetate is a popular method for the production of acetic anhydride. In this process, iodide species play a crucial role. Lithium iodide reacts with methyl acetate to produce lithium acetate and methyl iodide. Next, the lithium acetate is converted to acetyl iodide which then goes on to form the acetic anhydride.

Unfortunately, one of the intermediates, methyl iodide, poses a serious threat to human health and plant safety. Methyl iodide can act as an acute neurotoxin. Inhalation of methyl iodide can lead to nausea, vomiting, vertigo, ataxia, and in large exposures pulmonary edema, coma, and death. Monitoring key locations around the plant for the presence of methyl iodide leaks is crucial to ensuring personnel safety.

Applied Analytics’ OMA-300 ultraviolet spectrometer provides an easy and effective way to monitor ambient levels of methyl iodide. Methyl iodide readily absorbs in the ultraviolet spectrum with a peak intensity at 260nm. The OMA-300 adds to this powerful signal by cleverly taking advantage of Beer-Lambert’s law. By extending the length of the flow cell, Applied Analytics increases the absorbance even when only traces of methyl iodide may be present in the air.

Methyl Iodide Absorbance Spectrum

Methyl Iodide Absorbance Spectrum

Further Reading

Subject Type
OMA-300 Process Analyzer Product page
OMA-300 Process Analyzer Data sheet
Advantage of Collateral Data Technical note
Multi-Component Analysis Technical note