Celli M, D'Eufemia P, Dommarco R, Finocchiaro R, Aprigliano D, Martino F, Cardi E, Giardini O
Istituto di Clinica Pediatrica, Università di Roma La Sapienza, Italy.
Clin Chem. 1995 May;41(5):752-6.
We developed a gas-chromatographic method to determine urinary mannitol and lactulose. The procedure for purification of urine by a resin was optimized for purification of analytes and high recovery; the aliquot of resin chosen (500 mg) was kept in contact with the urine for 1 min. The recoveries of mannitol and lactulose were > 85% at concentrations that include both normal and pathological values. Sugars were converted to oximes before the silylation step to avoid multiple peaks for the anomeric forms. The calibration was linear over the range 0.1-1 microgram of sugar injected. Analytical recovery of the sugars ranged from 90% to 95.3% for mannitol and from 90.4% to 95.8% for lactulose. The mean within-day imprecision (CV) was 6.2% for mannitol and 4.7% for lactulose; the between-day CV was 6.7% for mannitol and 5.1% for lactulose. A lactulose/mannitol ratio of 0.035 completely differentiated 28 normal children and 28 children with active gluten-sensitive enteropathy, whose mean ratios were 0.022 (SD 0.007) and 0.084 (SD 0.054), respectively.
我们开发了一种气相色谱法来测定尿中甘露醇和乳果糖。通过树脂对尿液进行纯化的程序针对分析物的纯化和高回收率进行了优化；所选用的树脂等分试样（500毫克）与尿液接触1分钟。在包括正常和病理值的浓度下，甘露醇和乳果糖的回收率均大于85%。在硅烷化步骤之前，将糖类转化为肟以避免异头物形式出现多个峰。在所注入糖类0.1 - 1微克的范围内校准呈线性。糖类的分析回收率对于甘露醇为90%至95.3%，对于乳果糖为90.4%至95.8%。甘露醇日内平均不精密度（CV）为6.2%，乳果糖为4.7%；甘露醇日间CV为6.7%，乳果糖为5.1%。乳果糖/甘露醇比值为0.035能完全区分28名正常儿童和28名患有活动性麸质敏感性肠病的儿童，他们的平均比值分别为0.022（标准差0.007）和0.084（标准差0.054）。
