Analyzing Organic Acids by Ion Chromatography

Many organic acids lack sufficient sensitivity for detection. In addition, other components commonly present in these types of samples have a high UV absorption, which can interfere with the detection of target analytes. Most carboxylic acids ionize sufficiently, making ion chromatography with suppressed conductivity detection the technique of choice to separate a large variety of organic acids with inorganic anions and detect them with high sensitivity while minimizing the sugar interferences.

Some organic acids are more highly regulated than others. See below for examples from various regulatory bodies.

• WHO: Suggests a provisional tolerable intake of benzoic acid of 5mg/kg body weight per day.
• Health Canada: Established a maximum level of benzoic acid of 1,000 ppm in fruit juice, jams, and packaged fish and meat products.
• FDA: Established a maximum level of acetic acid of 0.25% for baked goods, 0.8% for cheeses, 9.0% for condiments and relishes, 0.5% for fats and oils, 3.0% for gravies and sauces, 0.6% for meat products, and 0.15% or less for all other food categories.