Toennes S.W.H., Maurer H.H.
Institute of Pharmacology and Toxicology, Department of Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany

Methods. Purified ß-glucuronidase and arylsulfatase were co-immobilized on an agarose gel matrix and packed into 3 mL columns (for experimental details see the Proceedings of Interlaken).

Results. Our further studies showed that such columns were stable during a storage time of at least 6 weeks and that they could be used for at least 70 incubations without relevant decrease of the hydrolysis yields. The carry-over of analytes after incubation and elution of the urine sample could be avoided by rinsing the column with a tenfold column volume of 20% methanol-acetate buffer (0.1 M containing 0.5 M NaCl, pH 5.2). Known contaminants like dihydrocodeine, ibuprofen, paracetamol, perazine or phenobarbital spiked in very high concentrations into urine could completely be removed from the column. Field studies on efficiency of this procedure in routine analysis are now in progress and the results will also be presented.

Conclusions. Cleavage of conjugates by column packed immobilized ß-glucuronidase and arylsulfatase may be an effective and convenient alternative for the cleavage of conjugates and may be useful in automation of sample preparation.