1. 电导率的测定

2. 安 排安 排 预习时，洗净玻璃器皿（ 1 支 100mL 量筒， 2 个分液 漏斗， 7 支 25mL 比色管），一定要洗净，以免结果 偏高。 检查分液漏斗，不得涂抹凡士林。 星期四上午每人带一瓶水样（湖水、饮用水，等）。 星期四上午萃取油，下午做电导率实验并进行油的 测定。 星期四交上周的 2 份实验报告。

3. 2.3. Determination of Conductivity Purpose: To understand the principle of conductivity measurement, and to master the usage of conductivity meter and monitoring method.

4. Questions What are the factors affecting the sample conductivity? Total ion concentration, feature of the ions, temperature, viscosity Why no preservation reagent can be added into the water sample? It may change the conductivity.

5. R: resistance L: distance A: area S: conductance P: resistivity K: conductivity Q: conductance constant S

6. 1/R K 0.001 mol/L KCl, standard K=1431 g/cm K=Q/R det. cal.

7. 8. 紫外分光光度法矿物油的测定

8. 2.10. Determination of Petroleum Purpose: To understand the principle of petroleum determination. To master one of the sample pretreatment methods, liquid- liquid extraction. To get familiar with the operation of UV-Vis spectrophotometer.

9. Determination Methods UV method: All the compounds absorbing 220- 225nm lights will be counted as petroleum – overestimated Florescence method Only the compounds absorbing and emitting certain lights can be counted as petroleum – underestimated

10. Determination Wavelength Petroleum – hydrocarbons Alkenes (higher than 214 nm) Aromatic (about 254 nm)

11. Extraction One of the separation methods Liquid-liquid (L-L) extraction, liquid phase Solid phase extraction (SPE) Solid phase micro extraction (SPME)

12. Procedure 1.L-L extraction with cyclohexane: acidizing, partition, separation 2. Determination with UV: organic phase, dry, absorbance, wavelength 3. Data processing one calibration curve for one group, one sample for each student

13. Additional Questions Should the solutions of the calibration curve be extracted as the samples? And why? Discuss the possible deviation and error of this experiment.

14. Attention ！ 用萃取剂把取样的量筒漂洗过，并入 分液漏斗。 萃取液回收！ 萃取液定容后，加无水硫酸钠脱水。 绘制工作曲线，不过原点。