Analysis of aromatic sulfonates in water by solid-phase extraction and capillary electrophoresis.
The separation of 14 different aromatic sulfonates of environmental concern by capillary (zone) electrophoresis (CZE) is presented. A new off-line solid-phase extraction (SPE) enrichment procedure, that is compatible with CE analysis, was developed, using the styrene-divinylbenzene adsorbent LiChrolut EN. The combined method of SPE and CE allows the determination of aromatic sulfonates in water samples in the low microgram/l range. Separations are performed with a simple sodium borate buffer at pH 9.3. Analytes are detected by UV absorbance and fluorescence emission with a Xe-lamp excitation source, and both principles are compared. The recoveries for most of the sulfonates are > 70% for the extraction from spiked tap and river water. The average method precision is < 20% for replicate analyses. Very hydrophilic sulfonates cannot be extracted by this method. The detection limit of the combined method of SPE enrichment and CE analysis is approximately 0.1 microgram/l for 200-ml water samples. The performance of the method was checked with the analysis of river and contaminated seepage water.
Loos
R
R
Institute of Hydrochemistry, Technical University of Munich, Germany.
Niessner
R
R
D002138:Calibration; D019075:Electrophoresis, Capillary; D005618:Fresh Water / Q000032:analysis*; D006841:Hydrocarbons, Aromatic / Q000032:analysis* / Q000302:isolation & purification; D007202:Indicators and Reagents; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013451:Sulfonic Acids / Q000032:analysis* / Q000302:isolation & purification; D014874:Water Pollutants, Chemical / Q000032:analysis*
D006841:Hydrocarbons, Aromatic; D007202:Indicators and Reagents; D013451:Sulfonic Acids; D014874:Water Pollutants, Chemical