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Discrimination and Simultaneous Determination of Analogs by Derivative Spectrum Method

导数谱法鉴别及类似物的同时测定

基本信息

批准号：
63571027
负责人：
IWATSURU Motoharu
金额：
$ 1.34万
依托单位：
Teikyo University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63571027/
关键词：
Derivative spectrum UV absorption Paraben Surfactant Sodium lauryl sulfate Shift of wavelength Simultaneous determination Products analysis 徴分スペクトルパラオキシ安息香酸メチル FDAS法一次微分 BSA タンパク結合ナフトール・イエローS

项目摘要

As the preservatives, such as methylparaben, ethylparaben, propylparaben, and butylparaben, have similar absorption spectrum which show maximum at 253-254 nm, it is not possible to discriminate them by absorption spectrum only. The addition of surfactant into their aqueous solution caused the shift of the wavelength of maximum absortion. This solubilization phenomena made it possible to measure the partition parameter of the preservative between aqueous and micellar phase. The parameter values of alkylparabens in sodium lauryl sulfate solution were in the order of butyl->propyl->ethyl->methylparaben at all temperatures where experiment were done. This means that the longer the acylchain of alkylparaben, the more can be solubilized into micellar phase. This ended up greater shift length and bigger partition parameter values. The same results were observed not in sodium lauryl sulfate solution, but also in cetyltrimethylammonium bromide solution, Tween 20 solution, and octaethyleneglycol-n-dodecylether solution. Thus the discrimination of alkylparabens were attained through the measurement of partition parameter.It was confirmed that the shift length of the mixed parabens depended on the molar ratio of its constituents. This made it possible to determine the concentration of parabens only knowing the magnitude of shift length and total absorptivity at given (maximum) wavelength. This method can be applied to any systems where absorption shift occurs as long as surfactant can cause the shift. It is a great advantage, once the calibration curve are set, then we need only the shift length and absorptivity to calculate the concentration of each components. This method can be more useful where so many samples should be handled in shorter time such as products analysis.

由于防腐剂，如对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯，具有相似的吸收光谱，在253-254 nm处显示最大值，因此不可能仅通过吸收光谱区分它们。在它们的水溶液中加入表面活性剂，引起最大吸收波长的移动。这种增溶现象使得可以测量防腐剂在水相和胶束相之间的分配参数。对羟基苯甲酸烷基酯在十二烷基硫酸钠溶液中的参数值的顺序为丁基->丙基->乙基->甲基对羟基苯甲酸酯。这意味着对羟基苯甲酸烷基酯的酰基链越长，越能增溶到胶束相中。这导致了更大的移位长度和更大的分区参数值。在十二烷基硫酸钠溶液中没有观察到相同的结果，但在十六烷基三甲基溴化铵溶液、吐温20溶液和八甘醇-正十二烷基醚溶液中也观察到相同的结果。通过分配参数的测定实现了对羟基苯甲酸烷基酯的区分，证实了混合对羟基苯甲酸酯的位移长度依赖于其组分的摩尔比。这使得有可能确定对羟基苯甲酸酯的浓度只知道位移长度和总吸收率在给定的（最大）波长的幅度。该方法适用于任何发生吸收位移的体系，只要表面活性剂能引起位移即可。这是一个很大的优点，一旦校准曲线设置，那么我们只需要移动长度和吸收率来计算每个组分的浓度。这种方法在需要在较短时间内处理大量样品的情况下（如产品分析）更有用。