Supercritical fluid chromatography with post‐column addition of supporting electrolyte solution for electrochemical determination of tocopherol and tocotrienol isomers

Abstract

A supercritical fluid chromatography with electrochemical detection system was developed for the simultaneous determination of tocopherol and tocotrienol isomers. The supercritical fluid chromatography with electrochemical detection system was connected with an additional pump to create a flow path to add a supporting electrolyte solution. The supporting electrolyte solution was mixed with a mobile phase in a post‐column fashion, enabling the independent control of the separation and detection. After optimization of the measurement conditions, vitamin E isomers and an internal standard substance (2,2,5,7,8‐pentamethyl‐6‐hydroxychroman) were separated within 30 min using a mixture of supercritical carbon dioxide and methanol (99:1, v/v) as a mobile phase and a cyanopropyl column (4.6 mm inner diameter × 250 mm length, 5 μm). For the electrochemical detection, methanol containing 1.0 mol/L ammonium acetate was used as a supporting electrolyte solution, and the applied potential was set at +0.8 V. This analytical method showed good linearity (5–100 μg/mL) and repeatability (less than 2.5% relative standard deviation, n = 6) and was applicable to the determination of tocopherol and tocotrienol isomers in nutrition supplements.

Free and Esterified Tocopherols, Tocotrienols and Other Extractable and Non-Extractable Tocochromanol-Related Molecules: Compendium of Knowledge, Future Perspectives and Recommendations for Chromatographic Techniques, Tools, and Approaches Used for Tocochromanol Determination

“…The difference in sensitivity between SFC-FLD and SFC-DAD for tocochromanol determination is less pronounced (around 3–20 times, depending on homologue) [ 184 ] in comparison to the difference between LC-FLD and LC-UV (about 1000 times) [ 162 ]. Application of ECD with SFC has recently been demonstrated for the determination of Ts in vegetable oils [ 185 ] and Ts and T3s in nutrition supplements [ 186 ].…”

Separation and determination of triadimefon and its metabolites triadimenol enantiomers in fruit puree by supercritical fluid chromatography

“…The major mobile phase of this technique is supercritical carbon dioxide (CO 2 ), which shows a higher mass transfer rate and separation efficiency than the traditional organic mobile phase [23]. Research shows that SFC technology is more suitable for the analysis of isomers and structural analogs which can hardly be separated by traditional LC, and has been successfully applied to separate and determine chiral compounds [1,[24][25][26][27][28][29].…”

Ecofriendly appraisal of stability‐indicating high‐performance chromatographic assay of canagliflozin and metformin with their toxic impurities; in silico toxicity prediction

“…Liquid chromatography is still the most applicable technique of choice for the analysis of drugs, pharmaceuticals, amino acids, nucleic acids, carbohydrates, lipids, and polymers, [27][28][29][30][31]. Based on the aforementioned revealed date; the proposed HPTLC-densitometric method was a must as the first determination of CN, MT, their respective major degradation products, DG, CG, and MT toxic impurity, ML in laboratory prepared mixtures and pharmaceutically formulated combinations containing CN and MT after ICH validation and statistically comparing the proposed method's results with those of the reported method [9].…”