钼酸铵分光光度法测定绿茶中的茶多酚

采用钼酸铵分光光度法测定茶叶中的茶多酚含量。它是基于茶多酚在酸性条件下能与钼酸铵反应生成黄色钼酸酯,此物质在341nm处有最大吸收,用分光光度法测其吸光度,从而间接测定茶多酚含量。方法的线性范围为4×10-6～36×10-5g mL,ε=2.1×105L mol·cm,RSD=1 3%(茶多酚含量8×10-6g mL,n=11)。测定结果与标准法基本一致。     

硒(Ⅳ)-碘化物-罗丹明6G体系荧光猝灭反应测定茶叶中痕量硒

拟定了一个荧光猝灭法测定痕量硒（Ⅳ）的新方法。在盐酸介质中，硒（Ⅳ）氧化碘化钾的反应，其反应产物使罗丹明６Ｇ荧光猝灭。方法的检出限为１．２μｇ／Ｌ，线性范围为０～８０μｇ／Ｌ，方法简便快速，选择性好，用于茶叶样品中硒的测定，结果满意。     

高效液相色谱荧光检测法测定福建乌龙茶中痕量硒

本文研究了2,3-二氨基萘(DAN)与Se(Ⅳ)反应,生成4.5-苯并苤硒脑(NSD),利用环已烷萃取反应生成的络合物。将有机相注射入填充有μ一Bondapak C_(18)固定相的色谱柱,以环已烷-四氢呋喃(90:10)为流动相,流速为1.0 mL/min,进行HPLC一荧光检测。测定了福建乌龙茶中的微量硒。方法的精密度和回收度均好。检测限达0.12 ng。     

Application of a potentiometric electronic tongue as a classification tool in food analysis

This paper reports on the application of a potentiometric sensor array to the food analysis field, in order to distinguish simple tastes and to classify food samples. This array is formed by a set of non-specific all-solid-state potentiometric sensors and has been used in combination with principal component analysis (PCA) for the classification of food samples in batch and in flow injection mode. First attempt was to classify synthetic samples prepared with controlled variability. Once this ability is proven, satisfactory classification results are presented for commercial waters, orange-based drinks and tea samples. An interesting correlation is achieved between the natural juice content and its first calculated component, which allows for a very simple tool for screening purposes.     

差示分光光度法测定茶多酚的含量

基于茶多酚在酸性条件下还原 Fe3+ 为 Fe2 + ,Fe2 + 与铁氰化钾生成可溶性兰色配合物 KFe[Fe (CN) 6 ],用差示分光光度法测定其吸光度 ,从而可间接测定茶多酚的含量。方法线性范围为 2μg/m L～ 1 2μg/m L ,ε=1 .97× 1 0 5L· mol- 1· cm- 1,RSD=1 .3 % (茶多酚含量 8μg/m L,n=1 1 )。测定结果与标准方法基本一致     

流动注射化学发光法测定茶饮料中的茶多酚

在碱性条件下,茶多酚对鲁米诺-KMnO4化学发光体系具有较强的抑制作用,据此建立了茶多酚的流动注射化学发光测定法。该法的化学发光抑制值ΔICL与茶多酚质量浓度在2.0×10-6~5.0×10-4mg/mL范围内,呈现出良好的线性关系,检出限为1.2×10-7mg/mL,对1.0×10-5mg/mL茶多酚测定的相对标准偏差为2.9%(n=11)。用于茶饮料中茶多酚的测定。     

云南名香烟等嗜好物品含氟量的研究

本文报道了（１）十二种云南高档和普通香烟含氟量为５．４４３４×１０－６～８．５８４×１０－６，平均７．２２３±０．９９４０×１０－６，湖南笑梅、Ｍｏｒｅ香烟含氟显为１２．５４２×１０－６和６．１４８×１０－６；（２）用高氟玉米和小麦酿造的６０°和５０°白酒，含氟量分别为０．０７４±０．００４ｍｇ／Ｌ和０．０７６±０．００６ｍｇ／Ｌ；（３）西双版纳和广东大丰咖啡及雀巢咖啡含氟量范围１．６７２×１０－６～４．４４６×１０－６，平均３．１１０×１０－６±１．３０６×１０－６；（４）昆明市售花茶、红茶、绿茶、砖茶共３０份，含氟量分别为７５．５×１０－６±７．０７×１０－６、１０．４．１３×１０－６±６０．６６×１０－６、６２．２×１０－６±４８．０８×１０－６和３０５．５×１０－６。上述四种嗜好物品除茶叶含氟量高，饮茶过量会引起氟中毒外，其余三种与氟中毒关系不大．     

Optimization of a new resin, Amberlyst 36, as a solid-phase extractor and determination of copper(II) in drinking water and tea samples by flame atomic absorption spectrometry

A new simple and reliable method has been developed to separate and preconcentrate trace copper ion in drinking water and tea samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). The copper ions are adsorbed quantitatively during passage of aqueous solutions through Amberlyst 36 cation exchange resin. After the separation and preconcentration stage, the analyte was eluted with a potassium cyanide solution and determined by FAAS. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of aqueous solution, volume and concentration of eluent, and matrix effects for preconcentration were examined. The analytical figures of merit for the determination of copper are as follows: analytical detection limit (3 sigma), 0.26 microg/L; precision (RSD), 3.1% for 100 microg/L; enrichment factor, 200 (using 1000 mL of sample solution and 5 mL of eluent); time of analysis, 3.5 h (for obtaining enrichment factor of 200); capacity of resin, 125 mg/g. The method was applied for copper determination by FAAS in tap water, commercial natural spring water, commercial treated drinking water, and commercial tea bag sample. The accuracy of the method is confirmed by analyzing tea leaves (GBW 07605). The results demonstrated good agreement with the certified values.     

电流氧化溶出计时电位法同时测定茶叶和生物样品中铅铜镉

提出了在HCl-Fe     

原子吸收光谱法测定茶叶中钙

采用原子吸收分光光度法对国内一些常用茶叶中的钙进行了测定 ,结果表明 ,茶叶中的钙含量丰富 ,为 12 14— 2 874 mg/kg,饮茶对人体健康有益。但茶汤中的钙浸出量仅为 2 3— 10 6 mg/kg,浸出率约 1.0—7.0 %。