Waugh W H
Clin Chem. 1977;23(4):639-45.
Described are a macromethod for measuring 2 to 30 mug of polyfructoside in sample volumes of 0.5 ml and a micromethod for measuring 40 to 400 ng in 10-mul samples. The absorptivity of the cysteine/tryptophan color product is 2.5-to 10-fold those found with use of five other colorimetric methods for inulin. The method is highly specific for alkali-stable polyfructoside. Color, measured at 515 nm, was maximal on development at 56 degrees C for 25 min in dilute (57-58% by vol) sulfuric acid, after the addition of the combined cysteine hydrochloride/tryptophan reagent. Analytical recoveries of inulin and polyfructosan from plasma and urine were complete. With initial alkaline heating, the endogenous blank inulinoid values averaged 0.6 +/- 0.47 (SD) mg/liter for plasma and 0.05 +1- 0.024 mg/min for urine. The coefficient of variation of the macromethod was less then 3%; that for the micromethod ranged from 1.3 to 6.3%. The micromethod appears adaptable to the determination of nanogram quantities of polyfructoside in nanoliter volumes of biological fluids.
本文描述了一种用于在0.5毫升样品体积中测量2至30微克多聚果糖苷的常量法，以及一种用于在10微升样品中测量40至400纳克的微量法。半胱氨酸/色氨酸显色产物的吸光度是使用其他五种菊粉比色法所测得值的2.5至10倍。该方法对碱稳定的多聚果糖苷具有高度特异性。在加入盐酸半胱氨酸/色氨酸混合试剂后，于56℃在稀硫酸（体积分数57 - 58%）中显色25分钟后，在515纳米处测量吸光度，此时颜色达到最大值。从血浆和尿液中对菊粉和多聚果糖的分析回收率良好。经初始碱性加热后，血浆中内源性空白菊粉样值平均为0.6±0.47（标准差）毫克/升，尿液中为0.05±0.024毫克/分钟。常量法的变异系数小于3%；微量法的变异系数在1.3%至6.3%之间。微量法似乎适用于在纳升体积的生物流体中测定纳克量的多聚果糖苷。
