Analysis of Unsaponifiable Compounds of Edible Oils by Automated On-Line Coupling Reversed-Phase Liquid Chromatography−Gas Chromatography Using the Through Oven Transfer Adsorption Desorption Interface

• Published in: Journal of agricultural and food chemistry Vol. 54; no. 19; pp. 6963 - 6968
• Main Authors: Cortés, J.M, Sanchez, R, Villen, J, Vazquez, A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20.09.2006
• Subjects: accuracy; adsorption; Autoanalysis; Biological and medical sciences; chemical compounds; Chromatography, Gas - methods; Chromatography, High Pressure Liquid - methods; Computers; cooking fats and oils; desorption; Dietary Fats, Unsaturated - analysis; Fat industries; food composition; Food industries; Fundamental and applied biological sciences. Psychology; gas chromatography; laboratory techniques; new methods; pretreatment; Reproducibility of Results; reversed-phase liquid chromatography; Saponins - chemistry; Sensitivity and Specificity; solvents; through oven transfer adsorption desorption interface; triacylglycerols; unsaponifiable compounds; on-line coupling; Liquid chromatography; Desorption; Edible oil; edible oils; Reversed phase chromatography; Adsorption; unsaponifiable compounds; Unsaponifiable; Transfer; TOTAD interface; Reversed-phase LC-GC; Gas liquid chromatography; Interface
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf060956e

An automated method for analysis of unsaponifiable compounds in edible oils is presented. The method involves the on-line coupling of reversed-phase liquid chromatography and gas chromatography (LC−GC) using the through oven transfer adsorption desorption (TOTAD) interface. The oil is injected directly with no sample pretreatment step other than filtration. It may also be considered to dilute the oil sample. In the LC step, a short C4 column using a methanol/water eluent separates analytes from the other components of the oils, which are made up of mainly triglycerides. A LC fraction of up to 1.6 mL containing the analytes is transferred to GC at a flow rate of 0.1−2 mL/min. The TOTAD interface allows solvent venting and the introduction of the analytes into the GC column. The proposed fully automated method allows the analysis of different groups of compounds (free sterols, tocopherols, squalene, and erythrodiol and uvaol) in one chromatographic run or the analysis of these compounds in different groups. Sensitivity is more than necessary, and repeatability is good, the CV ranging from 3 to 12% for the full analysis. Keywords: Reversed-phase LC−GC; on-line coupling; TOTAD interface; unsaponifiable compounds; edible oils