固相萃取－高效液相色谱法测定对虾体内土霉素残留量

用绞碎机破碎对虾样品，加入０．１ｍｏｌ／ＬＥＤＴＡ－Ｍｃｌｌｖａｉｎｅ缓冲液匀浆，匀浆液离心后，上层清液加入ＮａＣｌ脱蛋白，再次离心，过滤，滤液经Ｓｅｐ－ｐａｋＣ＿（１８）固相萃取小柱富集后，用高效液相色谱法分析。

Eu^（3＋）在EastmanAQ－29D化学修饰电极上的电化学行为

研究了Ｅｕ￣（３＋）在ＥａｓｔｍａｎＡＱ－２９Ｄ化学修饰电极上的电化学行为。研究表明，在ｐＨ４．４的０．１ｍｏｌ．Ｌ￣１ＮａＣｌＯ＿４底液中，Ｅｕ￣（３＋）的还原一氧化过程是一种半无限状态；在最佳测试条件下，Ｅｕ￣（３＋）的还原峰高在１．０×１０￣７～１．０×１０￣（－５）ｍｏｌ·Ｌ￣（－１）范围内有良好的线世关系。用计时库伦法测定Ｅｕ￣（３＋）在聚合物涂层中有效电荷迁越的扩散系数Ｄ＿（ａｐｐ），其平均值为（３．２±１．１）×１０￣（－１１）ｍ￣２·ｓ￣（－１）。

Electrochemical Behavior of Eu^（3＋） on Eastman AQ－29D Chemically Modified Electrode

The electrochemical behaviors of Eu3+ on Eastman AQ-29D/glassy carbon(GC) chemically modified electrode(CME) were studied. It was found that the reduction-oxidation process of Eu3+ is in a semi-infinite condition in 0.1 mol/L NaCIO4 supporting electrolyte(pH 4.4). The calibration curve was linear over the range 1.0×10-7 to 1.0×105 mol/L of Eu3+.The charge transport apparent diffusion coefficient of Eu3+ in the polymer film was determined to be(3.2±1.1)×10-11cm2/s by chronocoulometry.