污泥中总碳和总有机碳检测方案(有机元素分析)

APPLICATION NOTEE-CN-001-2019/A1 CARBON AND NITROGEN DETERMINATION IN SOILCOMBUSTION METHOD Total Carbon and NitrogenDetermination in Soil Reference： ISO 10694： Soil quality -Determination of organic and total carbon after dry combustion (Elemental analysis)； ISO 13878： Soil quality - Determination of total nitrogen content by dry combustion (Elemental analysis) EN13654-2： Soil improvers and growing media-Determination of nitrogen -Part 2： Dumas methodGazzetta ufficiale Official Italian Method 248.1999 Tested with VELP Scientifica CN 802 Carbon Nitrogen Analyzer (Code F30800090) Introduction A carbon-to-nitrogen ratio (C：N ratio) is a ratio of the mass of carbon to the mass of nitrogen in a substance. Forexample， if we have a C：N ratio of 24：1， this means we have 24 units of carbon to 1 unit of nitrogen. The C：N ratio isimportant because it has a direct impact on residue decomposition and also nitrogen cycling in soils. It can， amongst other things， be used as indicator for nitrogen limitation of plants and other organisms. As a rule ofthumb， the higher the ratio， the longer it takes for the material to decompose. Likewise， the smaller the ratio is， the morerapidly the plant material will decompose. This also has a direct relationship with the amount of nitrogen that is tied up inthe soil that will be available to the next growing plant. The performance of the VELP CN 802 was evaluated by participating in the Proficiency Testing program organized byWEPAL (Wageningen Evaluating Programs for Analytical Laboratories). Samples of soil were analyzed using the CN 802 and the results obtained (as C % andN %) were compared with thestatistical range accepted by WEPAL. Carbon and nitrogen determination in soils The elemental analysis starts with a combustion (CF) toburn the sample， obtaining elemental compounds. Water is removed by a first physical trap (WT1-DriStepTM)， placed after the combustion， and a secondchemical one (WT2). Between the two， the elementalsubstances passed through a reduction furnace (RF). VELP exclusive Non Dispersive Infrared NDIR Detectoraccurately measures the CO2 concentration that the unitis able to convert in carbon quantity. Then， the auto-regenerative CO2 absorbers (CO2) let pass only theelemental nitrogen that is detected by the innovativeLoGas TM Thermal Conductivity Detector (TCD) with norequirement for a reference gas. The CN 802 is controlled via PC through the intuitiveCNSoft TM. Sample Preparation 4 reference samples： Wepal ISE 2018-4 Sediment sample 860C%=4.524±0.207N%=0.1628±0.0132Wepal ISE 2018-4 Clay sample 879c%=2.911±0.072N%=0.1688±0.0126Wepal ISE 2018-4 Sandy soil sample 919c%=2.586±0.207N%=0.1487±0.0142 Wepal ISE 2018-4 Sandy soil sample 993 Expected values on dry matter： C%=2.624±0.119 N%=0.2361±0.0117 Soils samples have been dried at 105°C before the analysis.Using a spatula， put 300 mg of sample into the tin foil. Close the tin foil， obtaining a capsule and load the capsule intothe autosampler. Analysis Procedure Fill the following fields in the database： Sample name， Weight， Method， Sample type， Calibration number Create a new customizable method with the following parameters： Protein factor： none O2 flow rate： 300 ml/min O2 factor： 0.7 ml/mg Press to start the analysis. Analysis time： from 3 minutes for one run. Typical C and N Results on Soil samples Carbon results have been obtained with the calibration curve using the standard CaCO3 (C%=12)， in a range of0 -20 mg C. For Nitrogen results， the standard used for the calibration curve has been aspartic acid (C4H7NO4)， in therange of 0- 1.5 mg N. The data obtained are included in the tolerance admitted by the certificate of analysis.All four Wepal reference samples have been analyzed ten times to evaluate the repeatability of the CN 802. The tablebelow shows the total carbon and total nitrogen results on dry matter， obtained simultaneously by the CN 802. Thesoftware CNSoftTM automatically calculates the ratio C：N， shown in the table. Sample C % (Average ±SD%) %N (Average ± SD%) C：N Wepal Sediment sample 860 4.498±0.158 0.175±0.011 25 Wepal Clay sample 879 2.844±0.006 0.171±0.013 15 Wepal Sandy soil sample 919 2.531±0.084 0.160±0.007 15 Wepal Sandy soil sample 993 2.595±0.065 0.239±0.012 11 n = 10 Conclusion VELP Scientifica CN 802 Carbon Nitrogen Analyzer is the ideal solution for the determination of carbon and nitrogen andC：N ratio in soil samples. The analyzer ensures reliable results in easy and fast way with automatic calculation by thesoftware CNSoft M All data obtained are acceptable and comparable to the expected values， demonstrating excellent repeatability andaccuracy of the CN 802 Analyzer with no memory effect observed. With high productivity and non-stop performances， CN 802 combustion apparatus is ideal for high throughput， being fullyautomated and requiring from 2-5 minutes per analysis. Connecting the CNSoftM to VELP Ermes Cloud Platform it’s possible to easily monitor the analysis in real time via PC，smartphone or tablet. Copyright C VELP Scientifica. All rights reserved.No part of this publication may be reproduced or transmitted in any form or for any purpose without the express permission of VELP.VELPScientifica， Italy-Tel：+ Fax： +www.velp.com     污水处理厂产生的污泥由于其自身的特点，越来越受人们的关注。具有改善土壤性质和提供对植物生长至关重要的营养和微量元素补充的潜力。总碳“TC”可分为总有机碳“TOC”和总无机碳“TIC”，即有机和无机化合物中总碳的浓度。TOC的测定非常重要，因为土壤中高浓度的TOC阻碍了厌氧消化过程，限制了底土氮的富集。   意大利VELP CN 802的性能是通过参加WEPAL组织的能力测试计划(瓦格宁根评估分析实验室的项目)来评估的。采用CN 802对污泥样品进行分析，并与WEPAL所接受的统计范围进行比较。   CN 802型燃烧装置具有高生产率和不停机性能，以氦气和氩气为载气，完全自动化，每次分析仅需2-5分钟。将系统连接到VELP Ermes云平台，可以通过PC、智能手机或平板电脑方便地实时监控分析结果。样    品：两个参考污泥样品和一个未知污泥样品。仪    器：CN802碳氮元素分析仪检测指标：对每种污泥样品进行了两种不同的混配分析:          -直接用CN 802测定总碳(TC)          -盐酸酸化后测定总有机碳(TOC)实验结果：   VELP CN 802碳氮分析仪是污泥样品中总碳(TC)和总有机碳(TOC)测定的理想仪器。该分析仪采用CNSoftTM软件自动计算，快速简便，结果可靠。所获得的数据均为可接受的，与预期值具有可比性，说明CN 802分析仪具有良好的重复性和准确性。