溴甲酚绿增色分光光度法测定γ-环糊精  

Hyperchromic Spectrophotometric Determination of γ-Cyclodextrin with Bromocresol Green

作　　者：刘虹[1] 顾正彪[1,2] 洪雁[1] 李兆丰[2] 

机构地区：[1]江南大学食品学院,江苏无锡214122 [2]食品科学与技术国家重点实验室,江苏无锡214122

出　　处：《食品与生物技术学报》2009年第4期451-455,共5页Journal of Food Science and Biotechnology

基　　金：国家863计划项目(2006AA10Z335)

摘　　要：研究了溴甲酚绿分光光度法定量测定γ-环糊精的条件。在pH为4．1的酸性环境中，γ-环糊精使溴甲酚绿发生增色反应，最大增色波长为640nm，其增色程度（△A）与γ-环糊精质量浓度在0～0．3g／L的范围内成线性关系。回归方程为：△A=1．0327 CrCD（g／L），线性相关系数R^2为0．9957。该方法具有很高的灵敏性，表观摩尔吸光系数ξ640=1．7×10^6L／（mol．cm），对γ-环糊精的检出限为7．3×10^-4 g／L。样品平均实测回收率为96％～101．3％，RSD为0．071％，可用于γ-环糊精的定量测定。In this manuscript, a easy, economic and efficient determination method of γ- cyclodextrin （γ-CD） was developed based on the principle that γ-cyclodextrin （γ-CD） reacted with bromocresol green （BCG） to form BCG-（γ-CD） complexation at pH 4.1, which causes the hyperchromic of the BCG solution. The maximum hyperchromic wavelength is located at 640 nm. The optimum conditions of the reaction, the influencing factors and relationship between the hyperchromic intensity and the concentration of γ-CD has been investigated. The optimum conditions for measuring the γ-CD are as follows： pH 4.1,BCGconcentration 5 mmol/L , room temperature and 20 min reaction time The concentration of 7-CD is linear proportional to the degree of hyperchromic （△A） at the range of 0-0. 3 g/L. The regression equation is △A= 1. 032 7CrCD（g/L）, the correlation coefficient is 0. 995 7. The method has high sensitivity and the maximum molar absorption coefficient （ξ640） is 1.7 × 106 L · mol^-1 cm^-1, and the detection limit is 7.3×10-4 g/L. The recovery is 96%-101.3%, RSD is 0. 071%. The method with simplicity, stability system and good accuracy can be applied to the determination of γ-CD.

关 键 词：Γ-环糊精 溴甲酚绿 分光光度法 

分 类 号：O657.3[理学—分析化学] O636[理学—化学]