A rapid gas-liquid chromatography method for the determination of lactulose and mannitol in urine: Clinical application in studies of intestinal permeability

Abstract

Objective:The purpose of this study was to develop a gas-liquid chromatography method for the determination of the urinary excretion of two nonmetabolizable sugars (lactulose and mannitot) to estimate the intestinal permeability. Methods:Two internal standards (a-methyI-D-glucopyranosyde and sucrose) were added to the urine samples prior to derivatization with the aid of a solution of pyridine, [N, O-bis (trimethylsilyl)]-acetamide and chlorotrimethylsilan. Sample preparation was simpler and faster than in other previous methods and the four sugars were resolved within 27 min. Results:The inclusion of internal standards reduced the coefficient of variation from 9.44% to 4.78%. The method provided better sensitivity, range of analysis, and linearity than a previously published HPLC method reducing variances in the recovery of lactulose and mannitol added to urine. The clinical application of this method was tested in preterm infants fed human milk or cow's milk based formula and in breast fed term infants. Conclusion:The method described here for the determination of urinary lactulose and mannitol is more rapid, simpler, and more accurate than other previously published methods.

Modern approach for determination of lactulose, mannitol and sucrose in human urine using HPLC–MS/MS for the studies of intestinal and upper digestive tract permeability

“…Sample preparation is time consuming and derivatizing step requires additionally chemical reagents. Unlike enzymatic assays, it is possible to determine lactulose and mannitol simultaneously [22][23][24][25]. Determination of sugars by capillary electrophoresis is relatively rapid but requires solid phase extraction at sample preparation step.…”

Lactulose and mannitol intestinal permeability detected by capillary electrophoresis

“…Thin-layer chromatography [9] and colorimetric/enzymatic procedures [10] are timeconsuming and unspecific methods, HPLC must be coupled to a refractive index, pulsed amperometric, fluorescence or evaporative light scattering detector [11][12][13][14][15][16][17], not always available in all analytical laboratories, while gas chromatography or gas chromatography-mass spectrometry needs a derivatization step [18][19][20][21][22].…”

Characteristics and Analytical Methods of Mannitol: An Update

“…Diverse laboratory methods have been proposed for the measurement of mannitol and lactulose in urine, such as spectrophotometric [102] and enzymatic [69, methods, gas chromatography [116,118,120,146], and high-performance liquid chromatography [117, 122-23, 128, 133, 137, 139-40, 147].…”