芳烃中溴指数测定检测方案(其它石油专用分析仪器)

APKF-0238en京都電子工業株式会社KYOTO ELECTRONICSMANUFACTURING CO.，LTD. APKF-0238en Application Note Measurement of bromine index by Karl Fischermoisture titrator (coulometric titration)-Application of one-component inner burette- 1.Scope The bromine indicates the amount of unsaturated bonds in petroleum product components. It isdefined as the number of milligrams of bromine consumed by 100 g of sample. This ApplicationNote introduces an example of bromine index measurement using a coulometric titration KarlFischer moisture titrator with the one-component inner burette. The sample is dissolved in a solvent and reacted by changing bromine ions to bromine throughelectrolytic oxidization. In coulometric titration (coulometry)， the amount of reacted bromine isdetermined from the amount of electricity (coulombs) required for this electrolytic oxidization.1.In this application， the one sample solution was measured using Karl Fischer moisture titratorwith the two-component and one-component inner burette. In the conclusion， the measurement results did not have much difference between two-componentor one-component inner burette. 2.Precautions In the case the reagent becomes turbid and white during measurement， replace it with the newreagent. The titration cell and inner burette used for the bromine index measurement should besufficiently cleaned and dried when used for moisture measurement. It is recommended that theinner burette for bromine index measurement be used exclusively for the measurement. 3. Post-measurement procedure Drain the reagent from the titration cell， then clean the titration cell， electrolysis electrode (innerburette)， and twin platinum electrode with methanol. 4. Apparatus Equipment Karl Fischer moisture titrator for coulometric methodOption Twin platinum electrode， Electrolytic electrode (one-component inner burette) 5. Reagents Anolyte A solution consisting of a mixture of 600 mL of acetic acid， 260 mL of methanol，and 140 mL of 1 mol/L potassium bromide solution. Catholyte (used for comparative test) 0.2 mol/L potassium chloride aqueous solutionTest solution 0.051 wt% solution which diluted cyclohexene with toluene as a trial sample(expected bromine index： about 99) 京都电子工业株式会社-可睦电子(上海)商贸有限公司 上海市徐汇区宜山路333号1201室电话：021-54488867 电邮： kemu-kem@163.com 网址： http：//www.kem-china.com 6.Procedure -Preparation- 1) Fill the titration flask with approximately 100 mL of anolyte. 2) The test solution is injected 20 to 100 uL by a syringe， then perform preliminary titration. -Measurement- 1) Collect a sample using a syringe and measure the mass. 2) Inject the sample from the syringe inlet of the titration cell and measure 3) Measure the syringe mass after sample injection. 4) The difference in the mass of the syringe before and after injection of the sample is used asthe sample collection volume. Follow the table below for the sample injection amount. Bromine index Sample amount (mgBr2/100 g) (g) less than 10 10 to 15 10-50 5 to 10 50-100 3 to 5 100-200 l to 3 200 or more to 1 7.Calculation Bromine Index (mgBr2/100g)=FA×(Data-Driftxt -Blank)/(Wt1-Wt2)×D×0.1 FA Collection factor (1.0) Data Total bromine content(ug) Drift Initial drift level (ug/s) Measuring time (s) Blank Blank level (Oug) Wtl Sample +Syringe (g) Wt2 Mass of empty syringe(g) D Dilution factor (1.0) 8.Example 一Parameter . (The above condition is an example. The setting condition depends on the model.) co Measurement time (h：m：s) Table 1 Result of measurement of bromine index(one-component inner burette) Sampling Bromine Bromine index Time amount (g) (ug) (mgBr2/100 g) (h：m：s) 1 3.5181 3507.2 99.69 0：01：08 2 3.3560 3353.0 99.91 0：01：09 3 3.3394 3333.1 99.81 0：01：12 Average 99.80 SD 0.11 RSD(%) 0.11 Table 2 Result of measurement of bromine index(two-component inner burette) Sampling Bromine Bromine index Time amount (g) (ug) (mgBr2/100 g) (h：m：s) 1 3.4962 3489.2 99.80 0：01：32 2 3.5591 3549.4 99.73 0：01：40 3 3.4951 3473.4 99.38 0：01：46 Average 99.64 SD 0.23 RSD (%) 0.23 都電子工業株式会社KYOTO ELECTRONICSMANUFACTURING CO.，LTD. 芳烃溴指数的测定(库仑滴定法) 应用资料(英文版)溴表示石油产品组分中不饱和键的量。定义为100克样品消耗溴的毫克数。本应用说明介绍采用无隔膜内筒的库仑滴定法测定溴指数的例子。样品溶解在溶剂中，通过电解将溴离子转化为溴。在库仑滴定(库仑法)中，反应溴的量是由电解所需的电量(库仑)确定的。在这个应用中，使用卡尔费休水分滴定仪的隔膜内筒和无隔膜内筒分别测量。结果表明，隔膜式和无隔膜内筒的测量结果差异不大。