Bao Y, Silva T M, Guerrant R L, Lima A M, Fox J W
Department of Microbiology, University of Virginia School of Medicine, Charlottesville 22908, USA.
J Chromatogr B Biomed Appl. 1996 Oct 11;685(1):105-12. doi: 10.1016/0378-4347(96)00159-4.
Clinically, the ratio of lactulose/mannitol excretion in urine after administration of these non-metabolized sugars has been used to evaluate the extent of malabsorption and intestinal permeability disruption in several infections and nutritional diseases, including human immunodeficiency virus (HIV) infection. A range of methodologies have been reported to determine the lactulose/mannitol ratio, including enzymatic assay, gas-liquid chromatography (GC), thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Most published methods involve tedious sample preparations, rendering them unsuitable for routine or automated clinical laboratory testing. We describe in this paper a method in which weak anion-exchange high-performance liquid chromatography in conjunction with a pulsed amperometric detector was used. It requires very simple sample preparation and avoids interference by other components present in the urine. The linear range of determination for mannitol, lactulose and glucose are up to 10 nmol, in a single injection. The limits of detection are 8, 12, 47 and 52 pmol, respectively, for mannitol, glucose, lactose and lactulose. The separation and quantification using this method are highly reproducible, yielding standard errors of less than 2.5% for retention times and less than 3.5% for quantitation. The ratios of lactulose/mannitol recovery in controls and in HIV-infected subjects with and without diarrhea showed striking differences, which are in close agreement with the published results derived with similar HPLC methods.
临床上，在给予这些非代谢性糖类后，尿中乳果糖/甘露醇排泄率已被用于评估多种感染和营养疾病（包括人类免疫缺陷病毒（HIV）感染）中吸收不良的程度和肠道通透性的破坏情况。已有一系列方法被报道用于测定乳果糖/甘露醇比率，包括酶法测定、气液色谱法（GC）、薄层色谱法（TLC）和高效液相色谱法（HPLC）。大多数已发表的方法涉及繁琐的样品制备，使其不适用于常规或自动化临床实验室检测。我们在本文中描述了一种使用弱阴离子交换高效液相色谱结合脉冲安培检测器的方法。它需要非常简单的样品制备，并且避免了尿液中其他成分的干扰。甘露醇、乳果糖和葡萄糖单次进样的测定线性范围高达10 nmol。甘露醇、葡萄糖、乳糖和乳果糖的检测限分别为8、12、47和52 pmol。使用该方法进行的分离和定量具有高度可重复性，保留时间的标准误差小于2.5%，定量的标准误差小于3.5%。对照组以及有腹泻和无腹泻的HIV感染受试者中乳果糖/甘露醇回收率的比率显示出显著差异，这与使用类似HPLC方法得出的已发表结果高度一致。
