A capillary electrophoresis method using a low-pH electrolyte solution and UV detector for the determination of 3-dimethylsulfoniopropionate (DMSP) in tissue extracts of marine algae is described. Adjusting the pH of the electrolyte to an acidic condition of around 3 resulted in a high separation between DMSP and other related sulfur compounds. Two methods were investigated. Water extracts of algal samples were directly applied to capillary electrophoresis and detected at 190 nm (direct method). In order to obtain high sensitivity, esterification of DMSP was carried out at 70°C for 40 min to keep the degradation of DMSP at less than 5%. The reaction mixture was determined at 254 nm (esterification method). A good linearity was shown in the concentration range from 0.50-20.0 mM with a detection limit of 0.25 mM (S/N= 3) for the direct method, and 0.02-5.0 mM with a 0.005 mM detection limit (S/N= 3) for the esterification method. For both methods, the repeatability (n = 3) of the migration time and the peak area were less than 0.7% and less than 3% as RSD, respectively. In addition, nearly similar values were obtained when both methods were applied to algal samples collected from Tokyo Bay, indicating the suitability of the methods for DMSP determination.
|Number of pages||6|
|Publication status||Published - 1 Dec 2001|
- Capillary electrophoresis
- Marine algae
- p-bromophenacyl ester