油菜籽中N/蛋白质检测方案(定氮仪)

智能文字提取功能测试中

APPLICATION NOTEF&F-D-K-005-2018/A1 DUMAS AND KJELDAHLMETHOD COMPARISON N/Protein Determination inRapeseeds Dumas and Kjeldahl method comparison Kjeldahl reference： AOAC 2001.11 Protein (Crude) in Animal Feed， Forage (Plant Tissue)， Grain， and Oilseeds；REG CE 152/2009； EN ISO 5983-2：2009 Animal feeding stuffs Dumas reference： AOAC 992.23 Crude Protein in Cereal Grains and Oilseeds， ISO 16634-1：2008 Oilseeds and animalfeeding stuffs Tested with VELP Scientifica DKL 20 Automatic Kjeldahl Digestion Unit (Code S30100210)VELP Scientifica UDK 169 Automatic Kjeldahl Analyzer with AutoKjel Autosampler (Code S30200160) andVELP Scientifica NDA 702 Dual Carrier Gas Dumas Nitrogen Analyzer (Code F30800080) N/PROTEIN DETERMINATION IN RAPESEED Introduction Rapeseed meal， called canola meal in North America， Australia and some other countries， is a high protein-containingmaterial that can be used as a feed for livestock and poultry. Typical meal contains a little less than 40% of protein；however it also contains about 12% of crude fiber. Thus it is used mostly in ruminant feeding. The protein value of rapeseedmeal is higher than that of the majority of other vegetable proteins containing both lysine and sulfur amino acids， and itsworldwide production is second only to soybean meal. Both Kjeldahl and Dumas techniques are officially approved for the determination of the protein content in seeds. Performances of VELP Kjeldahl system and Dumas unit were evaluated by participating in the proficiency testing programorganized by BIPEA (Bureau Interprofessionnel d'Etudes Analytiques). The obtained results (as % Protein) were compared with the BIPEA assigned values. Protein Determination in BIPEA sample Rapeseeds This application note compares the nitrogen/protein determination in rapeseeds by using NDA702 Dumas NitrogenAnalyzer and UDK169 Automatic Kjeldahl Analyzer with AutoKjel Autosampler. The specific methods used in this study are summarized briefly here. Kjeldahl method The modern Kjeldahl method consists in a procedure of catalytically supported mineralization of organic material in aboiling mixture of sulfuric acid and sulfate salt at digestion temperatures higher than 400 °C. During the process the organically bonded nitrogen is converted into ammonium sulfate. Alkalizing the digested solutionliberates ammonia， which is quantitatively steam distilled and determined by titration. Dumas method ee....oo The Dumas method starts with a combustion furnace(CF))to burn the sample，obtaininlggelementalcompounds. 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). The auto-regenerative CO2 absorbers (CO2) let passonly the elemental nitrogen that is detected by theLoGas TMMinnovativeThermal ConductivityDetector(TCD) with no requirement for a reference gas. The NDA 702 is controlled via PC through the intuitive DUMASoft TM. Samples BIPEA Rapeseeds ID： 11-0413-0058 Dumas protein： assigned value： 19.1±0.3 Kjeldahl protein： assigned value： 18.9±0.3 Sample has been grinded by using a laboratory grinder (particle size 1 mm). ( E-mail： sales@ensoultech.com ) N/PROTEIN DETERMINATION IN RAPESEED Kjeldahl analysis 1. Sample Digestion Weight about 0.8 grams in a nitrogen-free weighing boat (Code CM0486000) and transfer in a test tube.In each test tube add： ● 2 catalyst tablets VCM (code A00000274；3.5g K2SO4， 0.1 g CuSO4 5H20 Missouri) ● 2 antifoam tablets VS (Code A00000283) ● 20 ml concentrated sulfuric acid (96-98%) ● 5 ml hydrogen peroxyde (H2O2) Prepare some blanks with all chemicals and without sample. Connect the Digestion Unit to a proper Aspiration Pump (JP code F30620198) and a Fume Neutralization System(SMS Scrubber code F307C0199) to neutralize the acid fumes created during digestion phase. Digest the sample for 40 minutes at 300°C plus 90 minutes at 420°C， according to the method“Oats， barley， corn， rice，rye”(n°9 on DKL 20). 2.Distillation and Titration Let the test tubes cool down to 50-60 °C. Condition the UDK 169 unit by performing the Automatic Check up in Menu-System and a Wash down. Distill the samples selecting the predefined methods n°9. ●HH2O (dilution water)： 50 ml ·NNaOH (32%)： 70 ml VreceiverTM (A00000316)： 30 mlH ● H2SO4 (0.2 N) as titrant solution FProtein factor： 6.25 Distillation &Titration analysis time： from 4 minutes for one test. Dumas analysis NDA 702 Preliminary Operations (daily) Follow the operating manual to start the NDA 702 and check that the following parameters are set： Temperature Combustion reactor (Code A00000158)： 1030°C Temperature Reduction reactor (Code A00000226)： 650°C Flow rate MFC1 He： 190 ml/min Flow rate MFC2 He： 220 ml/min 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 EDTA， used for the curve creation. Sample Preparation (NDA 702) Weigh around 150 mg of sample in a tin foil directly on the analytical balance. Close the tin foil， obtaining a capsule. Load the capsule into the autosampler. Analysis Procedure (NDA 702) Fill the following fields in the database of the software DumasoftTM： Sample name， Weight， Method， Sample type，Calibration number The “SEED MEAL" method shows the following parameters： Protein factor： 6.25 O2 flow rate： 400 ml/min O2 factor： 1.6 ml/mg PresS to start the analysis.Analysis time： from 3 minutes for one run.Results have been obtained with the following calibration curve： in a range of 0 - 7 mg N with 7 measurements of EDTAstandard (%N=9.57) (Code A00000149). The data obtained are included in the tolerance admitted by the EDTA certificate. ( E-mail： sales@ensoultech.com ) DUMAS AND KJELDAHL METHOD COMPARISON Results on BIPEA Rapeseeds samples Technique Sample quantity (mg) Nitrogen% Protein % Dumas 149.10 3.071 19.194 149.30 3.042 19.010 151.20 3.036 18.976 150.60 3.020 18.874 149.50 3.035 18.970 Average ± SD% 3.041±0.019 19.005±0.117 RSD%* 0.616 0.617 Kjeldahl 863.4 2.955 18.469 708.1 2.968 18.550 821.3 3.002 18.763 798.1 3.001 18.756 832.4 2.964 18.525 Average±SD% 2.978±0.022 18.613±0.137 RSD%* 0.738 0.738 Dumas assigned value：19.1±0.3%P Kjeldahl assigned value： 18.9±0.3% P Conclusions VELP is a leading company designing and manufacturing instruments for Nitrogen determination with the traditionalKjeldahl method and the innovative Dumas combustion method. The determination of Nitrogen and Protein in rapeseedsfell within the expected protein range indicated by BIPEA， demonstrating the high performances of both VELP equipment，UDK 169 Distillation Unit and NDA 702 Dumas analyzer. Excellent repeatability is ensured with both techniques， as demonstrated by low RSD values. NDA 702 Dumas combustionapparatus with high productivity and non-stop performances is indeed ideal for high throughput， being fully automated andrequiring just 3-4 minutes per analysis. VELP Kjeldahl system， using genuine catalyst tablets KJTabsTM， is a robust solution for protein determination in food andfeed field. The complete procedure was verified by using 5 ml of glycine standard solution (3%) containing 28 mg of nitrogen， asreference substance. ( 名称：北京盈盛恒泰科技有限责任公司 ) ( 电话：010-83993592 ) ( E-mail： sales@ensoultech.com ) 名称：北京盈盛恒泰科技有限责任公司地址：北京市西城区广安门外大街朗琴国际大厦B座电话：址：www.ensoultech.comE-mail： sales@ ensoultech.com 名称：北京盈盛恒泰科技有限责任公司地址：北京市西城区广安门外大街朗琴国际大厦B座电话：址：www.ensoultech.com       本文比较了NDA702 Dumas氮素分析仪和UDK169自动凯氏定氮仪与AutoKjel自动取样器对油菜中氮蛋白含量的测定。本文对本研究中使用的具体方法进行了简要总结。      油菜籽粕，在北美、澳大利亚和其他一些国家被称为油菜籽粕，是一种高蛋白物质，可以用作家畜和家禽的饲料。典型的一餐蛋白质含量略低于40%;然而，它也含有大约12%的粗纤维，因此，它主要用于反刍动物的喂养。菜籽粕的蛋白质价值高于大多数同时含有赖氨酸和硫氨基酸的植物蛋白，产量仅次于豆粕。凯氏定氮(Kjeldahl)和杜马斯(Dumas)技术都被批准用于测定种子中的蛋白质含量。实验样品：    BIPEA Rapeseeds    ID: 11-0413-0058    Dumas protein:       assigned value: 19.1 ± 0.3    Kjeldahl protein:     assigned value: 18.9 ± 0.3检测仪器：全自动凯氏定氮仪UDK169，消化炉DKL20，杜马斯定氮仪NDA702（全部为意大利velp）检测指标：蛋白质的测定检测结果：下表为NDA702 Dumas单元和VELP Kjeldahl体系得到的氮/蛋白结果。结论：VELP是一家设计和制造传统凯氏定氮法和创新的杜马斯燃烧法测定氮仪器的公司。油菜中氮和蛋白质的测定均在BIPEA指出的蛋白质预期范围内，说明VELP设备UDK 169蒸馏装置和NDA 702 Dumas分析仪的高性能。       这两种技术都保证了优良的重复性，低RSD值就是证明。NDA 702 Dumas燃烧装置具有高生产率和不间断性能，确实是理想检测设备，每次分析只需3-4分钟。VELP凯氏定氮系统采用KJTabsTM，是一种用于食品和饲料领域蛋白质测定的稳定解决方案。