d e n quantitation of small sulfamethazine peaks impractical. The chloroform wash of the basic aqueous mixture seems to affect this component m a t . Overwashing at this point, however, causes a loss of sulfamethazine.
Homogenizing or grinding the tissue prior to extraction tends to improve recovery somewhat but usually generates cleanup difficulties which negate the improved recovery.
Techniquea critical to reducing the noise level of the liquid chromatograph include the following:
- The solvent should be degassed to minimize the effect of emall bubbles which are not visible but give detector response.
Thia procedure ale0 helps prevent buildup of air in the pump head, which would result in pulsations.
All fittin@ should be very tight to eliminate even the smallest leaks.
-
Detector electronics and cell windows should be dry, and any air or gas ueed to purge the reference cell should be scrupulously clean and dry.
-
In mme instances, an arrangement to equilibrate the solvent thermally to the temperature of the detector might be helpful.
The electrical line to which the chromatograph is connected must be free of interference and large fluctuations. Both the chromatograph and the recorder should be well grounded.
The f d aqueous solution must be adjusted to pH 8.5-9.0 before evaporation to reduce the volume. If the solution is acidic at thii point, the sulfamethazine can be hydrolyzed to sulfanilamide and rulfanilic acid which elute with tissue components.