“…In six non-pregnant females in follicular and luteal phases, treatment of the urine with 0-glucuronidase increased the urinary recovery of conjugated and unconjugated EM and metabolites five-fold (n = 6; mean 46%; Table 1). A high concentration of ,3-glucuronidase (12,500 U) and a long incubation time (48 h) were used, as the conjugates of EM were more resistant to hydrolysis than those of MO (Predmore et al 1978) and of NEM (unpublished observations). As the ,-glucuronidase preparation used is contaminated with arylsulphatase, we investigated whether incubation with corresponding amounts of this enzyme increased the recovery in two urine specimens.…”