采用离子对试剂同时测定啤酒中异α-酸和还原异α-酸

建立了使用离子对试剂同时检测啤酒中异α-酸、二氢异α-酸、四氢异α-酸和六氢异α-酸的反相高效液相色谱法。实验采用四丁基氢氧化铵-磷酸缓冲液(pH调至7.2)-乙腈为流动相,Xterra RP C18(4.6×150 mm,5μm)色谱柱,等度洗脱,实现这4种异构化α-酸的所有组分的有效分离测定。各组分色谱峰保留时间的RSD为0.1%～0.3%,峰面积的RSD为0.5%～1.7%(n=7),重现性和线性关系较好;4种异构化α-酸的加标回收率为96%～108%。该方法无需样品处理,简便易行,可用于分析啤酒中所含异构化α-酸的种类和含量。

Simultaneous determination of iso-alpha-acid and reduced iso-alpha-acids in beer using ion pair reagent by HPLC

A method for the simultaneous determination of iso-alpha-acid,dihydro-iso-alpha-acid,tetrahydro-iso-alpha-acid and hexahydro-iso-alpha-acid in beer using ion pair reagent by reversed phase high performance liquid chromatography is described.The assay was conducted on a Xterra RP C18(4.6×150 mm,5 μm)column using isometric elution with a tetrabutylammonium hydroxide-phosphoric acid buffer at a pH of 7.2.All of components were separated completely.Good linear relationship and reproducibility were obtained.RSDs were 0.1%～0.3% and 0.5%～1.7% for retention time and peak areas,respectively.The average recoveries were 96%～108%.The method was operated simply without sample pretreatment,and it can be used to analyze the types and contents of iso-alpha-acid and reduced iso-alpha-acids in beer.