Ion-Exclusion High-Performance Liquid Chromatography of Aliphatic Organic Acids Using a Surfactant-Modified C18 Column

Abstract

Ion exclusion chromatography (IELC) of short chain aliphatic carboxylic acids is normally done using a cation exchange column under standard HPLC conditions but not in the ultra-HPLC (UHPLC) mode. A novel IELC method for the separation of this class of carboxylic acids by either HPLC or UHPLC utilizing a C18 column dynamically modified with sodium dodecyl sulfate has been developed. The sample capacity is estimated to be near 10 mM for a 20 µL injection or 0.2 µmol using a 150 × 4.6 mm column. The optimum mobile phase determined for three standard mixtures of organic acids is 1.84 mM sulfuric acid at pH 2.43 and a flow rate of 0.6 mL/min. Under optimized conditions, a HPLC separation of four aliphatic carboxylic acids such as tartaric, malonic, lactic and acetic can be achieved in under 4 min and in <2 min in the UHPLC mode at 2.1 mL/min. A variety of fruit juice and soft drink samples are analyzed. Stability of the column as measured by the retention order of maleic and fumaric acid is estimated to be ∼4,000 column volumes using HPLC and 600 by UHPLC. Reproducible chromatograms are achieved over at least a 2-month period. This study shows that the utility of a C18 column can be easily extended when needed to IELC under either standard or UHPLC conditions.

Closing the gap: an urgent need for newborn screening of organic acid disorders in developing countries

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Liquid Chromatography Analysis of Common Nutritional Components, in Feed and Food

“…They separated organic acids after optimizing sulfuric acid concentration, flow rate, and pH; an example of how a reverse column can be made more versatile. A wide array of compounds in juices and sodas were analyzed using ion exclusion chromatography [349]. For a detailed description of ion exclusion chromatography, we encourage the reader to pay special attention to this paper introduction.…”

Simple Spectrophotometric Method to Measure Surfactant CMC by Employing the Optical Properties of Curcumin’s Tautomers

“…1 Since surfactants are involved in numerous applications, a deep understanding of the micellization process is particularly important. 2,3 The narrow concentration range of surfactant at which micelles form is termed the critical micelle concentration (CMC). The values of the CMC can be determined by measuring the change of physicochemical properties that can occur in the solution due to micelle formation.…”

“…Micelles are aggregates of surfactants monomers arranged with the hydrophobic parts toward the center and the hydrophilic parts toward the surrounding aqueous solution . Since surfactants are involved in numerous applications, a deep understanding of the micellization process is particularly important. , …”