(Clinical Chemistry. 1998;44:1685-1691.)
© 1998 American Association for Clinical Chemistry, Inc.
|
General Clinical Chemistry |
Simultaneous HPLC determination with light-scattering detection of lactulose and mannitol in studies of intestinal permeability in pediatrics
Renzo Marsilioa,
Lorenzo D'Antiga,
Lucia Zancan,
Noemi Dussini,
and Franco Zacchello
Department of Pediatrics, University of Padua, Via Giustiniani 3, 35128 Padua, Italy.
a Author for correspondence. Fax 39-49-8213509.
We describe a new HPLC method for the simultaneous determination of
lactulose and mannitol in urine, in which cation-exchange
chromatography and evaporative light-scattering detection are used. The
two sugars are orally administered for the estimation of intestinal
permeability in children. Samples were purified by solid phase
extraction on a C18 cartridge and subsequent addition of
anion-exchange resin. Cellobiose may be used as an internal standard.
The chromatographic separation was carried out in 16 min at a flow rate
of 0.5 mL/min, using deionized water as the mobile phase.
Within-run precision (CV) measured at three concentrations was
1.6–2.3% for lactulose and 1.0–1.9% for mannitol. Between-run CVs
were 2.1–4.1% and 1.3–2.7% for lactulose and mannitol,
respectively. Analytical recovery of both sugar probes was 97–101%.
The detection limits (signal-to-noise ratio = 3) were 0.82 mg/L
for lactulose and 0.65 mg/L for mannitol. The lactulose/mannitol ratio
in control subjects was 0.024 ± 0.006; in patients with Crohn's
and coeliac diseases in active phase, the ratios were 0.200 ±
0.082 and 0.072 ± 0.025, respectively. The method is rapid,
simple, and sensitive, and suitable for determination of intestinal
permeability in children.
