Determination of α-Tocopherol in Plasma by High Performance Liquid Chromatography with Fluorescence Detection and Stability of α-Tocopherol under Different Conditions

Abstract

In order to study the clinical effects of the antioxidant alpha-tocopherol (tocofersolan, CAS 30999-06-5) a simple, robust, sensitive and reliable high performance liquid chromatography (HPLC) method using fluorescence detection for the daily measurement of alpha-tocopherol concentration in plasma is described. Several methods of HPLC analysis using fluorescence techniques are published, however, investigations of the stability of alpha-tocopherol during sample preparation under different conditions are relevant in the routine measurements and have to date not been reported. Therefore a modified method, both sensitive and robust, qualified for the day-by-day measurement of alpha-tocopherol in plasma was established and the stability of alpha-tocopherol during sample preparation was analysed under different conditions. This method enables the complete separation of alpha-tocopherol from other compounds within 14 min. In addition, investigations on the stability of alpha-tocopherol during sample preparation showed the necessity of rapid sample preparation without delay. Prepared samples can be stored in liquid nitrogen for at least 56 days.

Effects of Drought Stress on Photosynthesis Factors in Wheat Genotypes during Anthesis

“…The HPLC apparatus consisted of a florescent detector, and reversephase C 18 column at 25 °C. Excitation wavelength was 288 nm and emission wavelength was 329 nm (Rumelin et al 2004). …”

Fluorometric Determination of Vitamin Constituents in Human Plasma Using Ultra Performance Liquid Chromatography

“…Use of fluorescence detection provides the advantage of superior selectivity of these analytes as compared to ultraviolet detection in plasma, in addition to the advantages of short chromatographic run time and superior resolution often associated with UPLC analysis. Furthermore, this UPLC method yielded comparable to superior analyte detection sensitivity in comparison to previous HPLC assays in human plasma using fluorescence detection [32][33][34][35][36][37]40].…”

“…Although normal phase methods have been employed for the separation of some compounds [9][10][11][12][13], the vast majority of high performance liquid chromatography based fat soluble vitamin assay methods have employed reversed phase chromatography to facilitate analyte separation . Ultraviolet detection of these compounds has been most common in the literature [42][43][44][45][46][47], but fluorescence detection has also been used in the detection of tocopherol and retinol [32][33][34][35][36][37][38][39][40][41][42]. The use of fluorescence detection has allowed for various compounds to be analyzed at low limits of quantification and detection in plasma-human [32][33][34][35][36][37]40] or otherwise [39] as an alternative to ultraviolet detection methods.…”

“…Several methods have been developed for the simultaneous monitoring of tocopherol and retinol in human plasma [5][6][7][8][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]29,30,[32][33][34][35][36][37]40,[43][44][45][46]. These methods have often featured chromatography run-times and flow rates requiring considerable consumption of time and/or solvents during sample analyses [16-18, 20,21,29,35,47].…”

Synthesis, hydrolysis, and skin retention of amino acid esters of α-tocopherol

“…It shows a moisturizing effect, limiting trans‐epidermal water loss, and seems to be able to regulate keratin turnover. For stability reasons, α‐tocopherol is normally used in the form of esters, α‐tocopheryl acetate4, 5 or succinate, which once absorbed into the skin are hydrolyzed to α‐tocopherol, the active form of the vitamin 6–9. Recently, new derivatives of α,10 δ,11 and γ12 tocopherol were proposed.…”