润滑油、添加剂等样品中总氮检测方案

analytikjena analytikjena Short Application multi EASeries Determination of Nitrogen in Lubricating Oils， Additives and RelatedProducts Introduction Lubricating oils (motor oils) are used for the reduction of friction and noise emission and thereforea lessening of material wear in the gears. It consists of two main components， the synthetic ormineral base oil and a mixture of additives. Both components can contain small amounts ofnitrogenlcompounds.；.These are not desired anddcanniinfluence ttheelater performancecharacteristics of the product significantly. Some additives， which are added to the end product forimprovement of its performance characteristics， in contrast canncontain desired nitrogencompounds. These must also be determined and controlled. Sample Preparation and Analysis An analyzer of the multi EASeries was used with multi matrix sampler for the tests in thehorizontal operation mode. With the aid of the autosampler， samples can be dosed according totheir viscosity： either with a syringe (low viscosity or high viscosity following sample dilution)， orwith a quartz boat (high viscosity without sample dilution， solids， etc.). The automatic boat drivefeeds the dosed samples into the combustion system in a fully automated process using flamesensor technology. The quantitative thermal decomposition was done in a two-phase process. Thenitrogen content of the samples was determined afterwards with the help of a chemoluminescencedetector. Method settings The method TN_hori_solid rather TN_hori_liquid of the standard method library was used foranalyzing. Prior to the actual determination of the nitrogen content， the system is calibrated using standardsolutions (pyridine in isooctane) in the range of 0 - 100 mg/kg. Results Sample cN [mg/kg] SD [mg/kg] RSD [%] Scio_1 5.2 0.1 2.7 Scio_2 15.7 0.4 2.3 Lube_1 58.2 1.0 1.7 Lube 2 83.3 0.7 0.8 Summarv The horizontal operation mode of the analyzers of the multi EA Series are outstandingly suited forthe precise determination of the contents of nitrogen in lubricants. Thereby allows the multi-matrix sampler an optimal adjustment of the sample introduction processto the requirements of each matrix to be analyzed. During parallel operation of a UV fluorescencedetector the sulfur content can be recorded simultaneously. Moreover， the application spectrumcan be expanded with additional accessory modules to include the parameters chlorine andcarbon. Duplication and distribution permitted with reference to source. C 2007 Analytik Jena AG Publisher： Analytik Jena AG 07745 Jena Phone +49 (0) 3641/77-70 Konrad-Zuse-StraBe 1 Fax +49 (0)3641/77-92 79 Publisher：Analytik Jena AG07745 JenaKonrad-Zuse-StraBe 1 Determination of Nitrogen in Lubricating Oils， Additives and Related ProductsReference Number： EA__N_e||GRO/