橡胶轮胎中氮元素检测方案(定氮仪)

APPLICATION NOTEC-D-001-2013/A1 N DETERMINATION IN TYRE RUBBERDUMAS COMBUSTION METHOD 利用杜马斯燃烧法测定橡胶轮胎中的氮素含量 参考文献： ISO TC 45/SC2N2116橡胶，生胶乳.用杜马燃烧法测定氮含量 经由VELP Scientifica NDA 701 杜马斯氮分析仪测试(代码： F 30800070) 介绍 现代充气轮胎是由合成或天然橡胶，纤维和加了化合物的金属线制成的。充气轮胎广泛应用于各种车辆，包括汽车、自行车、摩托车，卡车，推土机和飞机。对轮胎制造商来说，重要的是要确定成品中氮的含量，因为氮的大量存在会产生不利影响，增加了轮胎过早失效的概率。 Modern pneumatic tyres are made by synthetic or natural rubber， fabric and metal wires with chemicalcompounds. Pneumatic tyres are used on many types of vehicles， including cars， bicycles， motorcycles，trucks，earthmovers， and aircraft. For tyre manufacturers it is important to determine the content of nitrogenpresent in the constituent mixture because a high presence of nitrogen adversely affects the performance ofthe tyre， increasing the incidence of premature failure of it. 橡胶轮胎中的氮素测定 杜马斯法从燃烧炉(CF)开始燃烧样品，得到主要的元素化合物。水是由第一个物理装置(WT1-滴滴)清除的，放置在燃烧步骤后和第二个化学装置(WT2)之前。在两者之间，元素物质通过还原炉RF流通. 自动产生的 CO2 吸附剂 (CO2)只允许氮元素通过，并且此过程可以由LoGas TM创新热导率检测器(TCD)检测，无需对比的气体。 NDA 701 由电脑通过直观的 DUMASoftTM软件控制. The Dumas method starts with a combustion furnace (CF) toburn the sample， obtaining elemental compounds.Water is removed by a first physical trap (WT1- DriStepTM)，placed after the combustion， and a second chemical one(WT2). Between the two， the elemental substances passedthrough a reduction furnace (RF).The auto-regenerative CO2 adsorbers (CO2) let pass only theelemental nitrogen that is detected by the LoGas TM innovative Thermal Conductivity Detectorri(TCD))with no requirement for a reference gas. The NDA 701 is controlled via PC through the intuitive DUMASoftTM. NDA 701 初步操作(日常) 按照操作手册指示启动NDA 701，并检查下列参数是否设置： 燃烧温度反应器(Code A00000158)：1030℃ 降温温度反应器(Code A00000226)： 650C 流速 MFC1 He： 190 ml/min 流速 MFC2 He： 200 ml/min 依据2 EDTA(代码A00000149)相关标准对系统进行调整，并检查3~5个空锡箔(代码A00000153)是否到位。进行一次或多次标准测试来验证校准曲线，测试同样适用于曲线的构建。 Follow the operating manual to start the NDA 701 and check that the following parameters are set： Temperature Combustion reactor (Code A00000158)：1030℃ Temperature Reduction reactor (Code A00000226)：650°C Flow rate MFC1 He： 195 ml/min Flow rate MFC2 He： 200 ml/mir Condition the system by testing 2 EDTA standard (Code A00000149) and 3 to 5 empty tin foils (Code A00000153) as Check up. Verify the calibration curve with one or more tests as Standard by testing the same standard used for the curvecreation. 样本准备 把汽车轮胎上的橡胶切成碎片，清洗纤维和金属部件。然后冷冻切割后的橡胶(于摄氏-10度左右)以加固，并用研磨机获得更好的均匀度(粒度约2毫米) 将重量约80毫克的轮胎橡胶直接放在锡箔中置于天平上。用手小 心地合上锡箔纸，获得一个“包裹”样本。 把它装进自动采集器。 Cut in pieces the rubber from a car tyre， clean it from fiber and metal parts. Freeze the cut rubber (around-10°℃)in order to enhancing the solidification and obtain a better homogenization with a grinder (particle size around 2mm) Weigh around 80 mg of tyre rubber directly in a tin foil placed on the balance. Close carefully the tin foil by hands， obtaining a capsule. Load it into the autosampler. 分析过程 在数据栏中输入以下信息：样本名称、重量、方法、样本类型、校准号 在“橡胶轮胎”模式下，显示以下参数： 蛋白质系数：无 02流速：400 ml/min O2系数：1.4ml/mg 按 来开始分析 分析时间：每次运行3分钟以上. Fill the following fields in the database： Sample name， Weight， Method， Sample type， Calibrationnumber. The TYRE RUBBER method shows the following parameters. Protein factor： none O2 flow rate： 400 ml/min O 2 factor： 1.8 ml/mg Pres to start the analysis. Analysis time： from 3 minutes for one run. 橡胶轮胎的典型结果 Sample quantity (mg) Nitrogen % 79.10 0.346 80.00 0.348 79.50 0.332 79.00 0.341 79.40 0.356 79.10 0.340 79.30 0.340 80.00 0.343 79.00 0.342 80.80 0.349 Average±SD% 0.344±0.006 RSD%* 1.885 Nitrogen Expected Value氮期望值： 0.2-0.5% (*)RSD%=(标准偏差*100)/平均值 结论 所得结果可靠，符合预期值。轮胎橡胶的含氮量符合该物质的规格要求(0.2

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