Figure 1

Typical chromatogram of EPIC Norfolk spot urine sample, showing γ-valerolactone-3′/4′-O-glucuronide (top, 3.9 minutes) and γ-valerolactone-3′-sulphate (bottom, 3.8 minutes) in urine.

Typical chromatogram of EPIC Norfolk spot urine sample, showing γ-valerolactone-3′/4′-O-glucuronide (top, 3.9 minutes) and γ-valerolactone-3′-sulphate (bottom, 3.8 minutes) in urine.