啤酒、麦芽中Glu检测方案(毛细管电泳仪)

HIGH PERFORMANCECAPILLARYELECTROPHORESIS SYSTEMWWW.LUMEX.BIZ DETERMINATION OF AMINO ACIDS IN BEER AND WORT BY CAPILLARYELECTROPHORESIS INTRODUCTION Free forms of amino acids in beer originate mostly from malt. The following method enables fast quantitativedetermination in beer and wort of the following free amino acids： arginine， lysine， tyrosine， phenylalanine，histidine， leucine and iso-leucine (total)， methionine， valine， proline， alanine， glycine， cystine， tryptophan，aspartic and glutamic acids. Total content of amino acids is fdetermined after hydrolysis of proteins.. MEASUREMENT METHOD Free amino acids are transformed to phenylthiocarbamyl derivatives (PTC derivatives) by means of phenyl-isothiocyanate and their ionic forms are separated in the quartz capillary under the action of an electric field.The PTC derivatives are determined by measuring their own absorbance at 254 nm wavelength in a buffersolution. MEASUREMENT RANGE Amino acid Measurementrange*， mg/L Amino acid Measurementrange*， mg/L Amino acid Measurementrange*， mg/L Ala 0.5-150 Gly 0.2-50 Pro 0.25-500 Arg 0.5-250 His 0.5-50 Ser 0.3-300 Asn 1.0-50 lle+Leu 0.5-150 Thr 0.5-50 Asp 0.5-50 Lys 0.5-100 Trp 1.0-50 GIn 0.5-50 Met 0.4-50 Tyr 1.0-150 Glu 1.0-50 Phe 1.0-150 Val 0.4-150 *sample 100 pL EQUIPMENT AND REAGENTS The“CAPEL-103RT/104T/105/105M” capillary electrophoresis system with a special capillary cassette forthe amino acid analysis is used in measurements. Data acquisition， collection， processing and output are performed using a personal computer running under“WINDOWSe 2000/XP”operating system with installed dedicated software package for acquisition andprocessing of chromatography data. All reagents must be of analytical grade or higher. EXAMPLE OF A REAL ANALYSIS Buffer： phosphate， with p-cyclodextrin The contents on this paper are subject to change without notice. 啤酒中游离氨基酸的形式主要来源于麦芽。毛细管电泳法可以快速定量测定啤酒和麦芽汁中的游离氨基酸：精氨酸、赖氨酸、酪氨酸、苯丙氨酸、组氨酸、亮氨酸和异亮氨酸（总）、蛋氨酸、缬氨酸、脯氨酸、丙氨酸、甘氨酸、胱氨酸、色氨酸、天冬氨酸和谷氨酸。游离氨基酸通过苯基异硫氰酸酯转化为苯基硫代氨基甲酸衍生物（PTC衍生物），其离子形式在电场作用下在石英毛细管中分离。通过在缓冲溶液中测量PTC衍生物在254 nm波长下的吸光度来确定其含量。