CAPILLARY ELECTROPHORETIC ANALYSIS OF THE SODIUM-SALT OF NAPHTHALENESULFONIC ACID, FORMALDEHYDE POLYMER IN WASTE-WATER USING A POLYETHYLENEGLYCOL-COATED CAPILLARY

Industrial surfactants such as the sodium salt of naphthalenesulfonic acid, formaldehyde polymer are widely used in manufacturing for proces s control. These water-soluble materials are eliminated with the waste water. This necessitates sensitive and accurate determinations of sur factant concentration in effluents as a prerequisite for effective pol lution abatement. Monitoring the concentration of these surfactants by conventional spectrophotometric tests which are currently in use is n on-differentiating and subject to gross interferences by many sources. Alternatively, determination of the above surfactant by HPLC methods has not been effective at resolving the various ionic species found. T his work describes the selective separation of anionic species by the suppression of the EOF through the judicious choice of a commercially available coated column which increases selectivity by eliminating neu trals and cations through a bi-directional separation system. This is a significant enhancement over traditional approaches like HPLC which observe all UV-absorbing components and interferences. This selectivit y is superior to that of the UV methods generating comparatively equiv alent CE results when no interferences are present, and more accurate CE results when interferences are present.