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The determination of choline in vitamin preparations, infant formula and selected foods by capillary zone electrophoresis with indirect ultraviolet detection
Author(s) -
Carter Nicole,
Trenerry V. Craige
Publication year - 1996
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.1150171023
Subject(s) - chemistry , chromatography , capillary electrophoresis , choline , tetramethylammonium hydroxide , repeatability , infant formula , ultraviolet , coefficient of variation , vitamin , detection limit , analytical chemistry (journal) , biochemistry , organic chemistry , materials science , optoelectronics
A method for the determination of choline in vitamin preparations, infant formula and selected foods by capillary zone electrophoresis with indirect ultraviolet detection at 214 nm is described. The “free” choline in the vitamin preparations was simply extracted with water, the solutions filtered and analysed. The “free” and “bound” choline in the other products was extracted with methanol. The near dry extract was then treated with hot saturated aqueous calcium hydroxide to hydrolyse the “bound” choline before analysis. A 75 cm × 75 μm uncoated fused silica capillary column with an electrolyte consisting of 5 m M 1‐methylimidazole, pH 4.5, and an operating voltage of 30 kV was used for all of the determinations. Using these conditions, choline migrates in less than 3 min and is well separated from the other components in the electropherograms. The tetramethylammonium ion was used as the internal standard. The instrument repeatability data for area calculation and migration time variation were good (coefficient of variation, CV, area calculation 1.4%, n = 10; CV for migration time variation 1.0%, n = 20). The level of detection for choline using this procedure is 5 mg/100 g.