Quantification of naphthyl conjugates. Comparison of high-performance liquid chromatography and selective enzyme hydrolysis methods

Abstract

1. An h.p.l.c. method for the simultaneous determination of naphthol, naphthyl glucuronide and naphthyl sulphate in urine is described. This procedure is based on the selective formation of an ion pair between the sulphate conjugate and tetrabutylammonium, which allows its resolution from the glucuronide on a reverse phase column.

2. The h.p.l.c. method is used to assess the selective enzyme hydrolysis method which is frequently employed in drug conjugate assays. Results suggest that the use of sulphatase and β-glucuronidase may give data which are quantitatively and qualitatively erroneous.