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4-Methylimidazole in Cola Soft Drinks

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UV Detection with Purospher® STAR RP-18e Columns


4-Methylimidazole (4-MI) is a heterocyclic compound derived from imidazole through substitution of the hydrogen in position 4 by a methyl group. It is a known animal carcinogen, which may be formed when carbohydrates and amino-containing compounds react during the browning of food. It can also be found within some fermentation processes, and in certain types of caramel coloring produced with ammonia or ammonia-sulfite based processes.

Recently, high levels of 4-Methylimidazole have been found in many cola soft drinks, including Coca-Cola, Pepsi-Cola, Diet Coke, and Diet Pepsi. It has also been detected in roasted foods, grilled meats, and coffee. Dark beers and common cola soft drinks may contain more than 100 μg of 4-Methylimidazole per 12-ounce canister.

Recent Regulations Regarding 4-Methylimidazole

4-Methylimidazole in cola soft drinks

In February 2011, the Center for Science in the Public Interest (CSPI) petitioned the United States Food and Drug Administration (US FDA) to withdraw its authorization for caramel colorings that contain 4-Methylimidazole, and in the interim to change the name of the additive to "ammonia-sulfite process caramel coloring" or "chemically modified caramel coloring" for labeling purposes. California has added 4-Methylimidazole to its list of probable carcinogens. Consequently, in March 2012, leading manufacturers of cola soft drinks declared to change their recipes to avoid a cancer warning label in compliance with Californian law.

A Reliable and Robust Solution for Detection of 4-MI

Accurate detection techniques are necessary in order to avoid the potential health risks of 4-Methylimidazole. The application example available below presents a simple yet robust analytical procedure for the direct analysis of 4-Methylimidazole in well known cola soft drinks, and light versions of these beverages. The method, which requires no prior sample preparation, relies on UV detection using pH stable Purospher® STAR C18-endcapped reversed phase (RP) columns.

Application Request: Determination of 4-Ml in Cola soft drinks

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  • Experimental conditions
  • Sample preparation
  • Tips & tricks
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  • Application to real samples
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