Szpylka John, DeVries Jon, Cheney Andrea, House Steve
General Mills/Medallion Laboratories, 9000 Plymouth Ave North, Minneapolis, MN 55427, USA.
J AOAC Int. 2012 Nov-Dec;95(6):1547-54. doi: 10.5740/jaoacint.cs2011_06.
The method for "Determination of Total Folates in Infant Formula and Adult Nutritionals by Trienzyme Extraction and UPLC-MS/MS Quantitation" was submitted to the Folate Working Group for consideration for adoption as Official First Action by AOAC INTERNATIONAL. This method uses ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) to determine the total folates in infant formulas and adult nutritionals after trienzyme digestion. Deconjugation of the various folate polyglutamates to folate monoglutamates is achieved by using rat plasma conjugase after the sample digestion with protease and a-amylase during the trienzyme digestion process. This method shows linearity of folate concentrations in the range of 10-19 100 microg/100 g. Extension of the range to cover folate concentrations of 5-2 000 000 microg/100 g can be achieved with appropriate adjustment of the sample weight and SPE cleanup loading volume. The recoveries ranged from 94.10 to 101.34%.
“通过三酶提取和超高效液相色谱-串联质谱法定量测定婴儿配方食品和成人营养食品中的总叶酸” 方法已提交给叶酸工作组，以供美国官方分析化学家协会（AOAC INTERNATIONAL）考虑作为官方首次行动采用。该方法采用超高效液相色谱/串联质谱法（UPLC-MS/MS），在三酶消化后测定婴儿配方食品和成人营养食品中的总叶酸。在三酶消化过程中，样品先用蛋白酶和α-淀粉酶消化，然后用大鼠血浆结合酶将各种叶酸多聚谷氨酸解偶联为叶酸单谷氨酸。该方法显示叶酸浓度在10 - 19 100微克/100克范围内呈线性。通过适当调整样品重量和固相萃取净化上样体积，可将范围扩展至涵盖5 - 2 000 000微克/100克的叶酸浓度。回收率在94.10%至101.34%之间。
