Sequential Injection Chromatography with an Ultra-short Monolithic Column for the Low-Pressure Separation of α-Tocopherol and γ-Oryzanol in Vegetable Oils and Nutrition Supplements

Abstract

A low-pressure separation procedure of α-tocopherol and γ-oryzanol was developed based on a sequential injection chromatography (SIC) system coupled with an ultra-short (5 mm) C-18 monolithic column, as a lower cost and more compact alternative to the HPLC system. A green sample preparation, dilution with a small amount of hexane followed by liquid-liquid extraction with 80% ethanol, was proposed. Very good separation resolution (Rs = 3.26), a satisfactory separation time (10 min) and a total run time including column equilibration (16 min) were achieved. The linear working range was found to be 0.4 -40 μg with R 2 being more than 0.99. The detection limits of both analytes were 0.28 μg with the repeatability within 5% RSD (n = 7). Quantitative analyses of the two analytes in vegetable oil and nutrition supplement samples, using the proposed SIC method, agree well with the results from HPLC.

Flow-based Analytical Techniques

“…8 Thaithet et al reported on sequential injection chromatography (SIC) using an ultra-short monolithic column for the separation of α-tocopherol and γ-oryzanol in edible oils and nutrition supplements. 9 The total analysis time, including column equilibration, is 16 min, and the obtained results agree well with the results from HPLC. At first, the application of SIC was limited to the determination of pharmaceutical samples; now it has been expanded to various samples, such as biological, food, and environmental analyses.…”