Mitchell G A, Vanderbist M J, Meert F F
J Assoc Off Anal Chem. 1982 Mar;65(2):238-40.
A gas-liquid chromatographic method is described for rapid, quantitative determination of adipate content of acetylated di-starch adipate. The adipate group is very labile and, under mild alkaline conditions at ambient temperature, is easily hydrolyzed from the starch. Free adipic acid is formed by acidification of the solution with HCl, and then extracted with ethyl acetate. Ethyl acetate is removed under vacuum distillation, and a silyl derivative of the adipic acid is formed. Glutaric acid internal standard is introduced into the original starch sample before hydrolysis. An aliquot of the silylated solution is injected into a gas chromatograph fitted with a column having silicone oil as the active phase. A flame ionization detector is also incorporated. Results correlate well the amount of adipylating reagent used. No adipic acid is detectable when a hydrolyzed, extracted sample of acetylated di-starch adipate is subjected to a second extraction. Recovery levels of adipic acid, from starches fortified with 100-500 ppm, are in the range of 97-102.5%.
描述了一种气相色谱法，用于快速、定量测定乙酰化己二酸双淀粉中的己二酸酯含量。己二酸酯基团非常不稳定，在室温下的温和碱性条件下，很容易从淀粉上水解下来。用盐酸将溶液酸化形成游离己二酸，然后用乙酸乙酯萃取。在减压蒸馏下去除乙酸乙酯，并形成己二酸的硅烷化衍生物。在水解前将戊二酸内标引入原始淀粉样品中。取一份硅烷化溶液注入配备有以硅油为固定相的色谱柱的气相色谱仪中。还配备了火焰离子化检测器。结果与所用己二酸酯化试剂的量相关性良好。当对水解、萃取后的乙酰化己二酸双淀粉样品进行二次萃取时，未检测到己二酸。在添加了100 - 500 ppm己二酸的淀粉中，己二酸的回收率在97 - 102.5%范围内。
