Separation of ι-, κ and λ-carrageenans by capillary electrophoresis

Abstract

The present study reports a novel method for the separation of the high-molecular-weight anionic polysaccharides, iota, kappa, and lambda carrageenans, in capillary electrophoresis (CE). Carrageenan samples are first derivatised with 9-aminopyrene-1,4,6-trisulfonic acid (APTS), separated in an ammonium acetate background electrolyte (BGE) and detected with laser-induced fluorescence (LIF). The effects of changes of instrumental parameters (temperature, injection mode, field strength) and the composition of the BGE (concentration and pH) are reported, and are explained in terms of the physical chemistry of the BGE and the biopolymers. Optimal separation conditions for kappa, iota, and lambda carrageenans, including an APTS internal standard, were found in a polyvinyl alcohol coated capillary with an ammonium acetate BGE of low concentration (25 mM) and moderate pH (8.0). This BGE gave the best reproducibility in tests on iota/kappa mixtures, with relative standard deviations (RSDs) in migration times and normalised peak areas (relative to the APTS internal standard) of less than 0.1% and 1%, respectively. Using this BGE at 50 degrees C and a voltage of 30 kV, all three carrageenan subtypes were separated in a run time of 3 min.

Prospective of the cosmeceuticals derived from marine organisms

“…Carrageenans, sulfated linear polysaccharides of alternating 1,3-linked β-D-galactopyranose and α-1,4-linked-Dgalactopyranose, extracted from various red algae of the family Rhodophyceae with molecular masses, approximately 300 and 600 kDa [24,25]. These molecular differences in carrageenans are due to the position and the number of sulfate groups and the presence of the anhydro bridge.…”

Recent advances in capillary electrophoresis methods for food analysis

“…2-Aminoanthracene was used as a derivatisation reagent to allow sensitive fluorescence detection and the method was applied to a range of standard gelling agents as well as to real food samples. More recently, CE was applied to the separation of i-, k-and l-carrageenans, which are highmolecular-weight anionic polysaccharides [37]. The carrageenans were derivatised with 9-aminopyrene-1,4,6-trisulfonic acid, separated using an ammonium acetate buffer and detected by LIF.…”

“…Experimental conditions: fused-silica capillary, 47 cm650 mm ID; buffer, 25 mM ammonium acetate (pH 8.0); field strength, 6.4610 4 V/m; electrokinetic injection, 3 s at 2.1610 4 V/m; temperature, 507C. Reproduced from[37].…”