燕麦片中N/蛋白检测方案(氮磷钙测定仪)

APPLICATION NOTEF&F-D-001-2017/A1 N/PROTEIN DETERMINATION IN OAT MEALDUMAS COMBUSTION METHOD hout the express permission of VELP. VELP Scientifica， Italy Tel： +39 039 628 811 Fax： +39 0396288120 www.velp.com N/Protein Determination in Oat Mealaccording to the Dumas method (He/Ar as Carrier) Reference： AOAC 992.23 Crude Protein in Cereal Grains and Oil seeds Tested with VELP Scientifica NDA 702 Dual Carrier Gas Dumas Nitrogen Analyzer (Code F30800080) Introduction The oat (Avena sativa)， sometimes called the common oat， is a species of cereal grain grown for its seed， which is knownby the same name (usually in the plural， unlike other cereals and pseudocereals). While oats are suitable for humanconsumption as oatmeal and rolled oats， one of the most common uses is as livestock feed. The established property oftheir cholesterol-lowering effects has led to acceptance of oats as a health food. Oats are also occasionally used in several different drinks as for example， beers or“avena”a drink from Latin America.Oat extracts can also be used in cosmetics also oat grass has been used traditionally for medicinal purposes， including tohelp balance the menstrual cycle， treat dysmenorrhoea and for osteoporosis and urinary tract infections. Protein Determination in Oat Meal The Dumas method starts with a combustion furnace (CF) to burn thesample， obtaining elemental compounds. Water is removed by a first physical trap (WT1-DriStepTM)， placed after thecombustion， and a second chemical one (WT2). Between the two， theelemental substances passed through a reduction furnace (RF). The auto-regenerative CO2 adsorbers (CO2) let pass only the elementalnitrogen that is detected by the LoGas TM innovative Thermal ConductivityDetector (TCD) with no requirement for a reference gas. The NDA 702 is controlled via PC through the intuitive DUMASoftTM. 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)： 1.030°C Temperature Reduction reactor (Code A00000226)：650°℃ Flow rate MFC1 (He/Ar)： 190 ml/minFlow rate MFC2 (He/Ar)： 220 ml/minCondition 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 curve creation. Sample Preparation Oat Meal Reference Material code A00000318 Expected Nitrogen range： 1，9±0，3% Grind the test samples using a grinder to suitable fineness (particle size ≤ 0.5 mm) to obtain ≤ 2，0 % relative standarddeviation (RSD) for 10 successive nitrogen determinations. Weigh around 150 mg of the homogeneous sample directly into the tin foil directly on the balance. Close the tin foil， obtaining a capsule and load the capsule into the autosampler. Analysis Procedure Fill the following fields in the database： Sample name， Weight， Method， Sample type， Calibration number The CEREAL MEAL 4 method shows the following parameters： Protein factor： 5.83 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. Typical Results on Oat Meal Results have been obtained with the following calibration curve： in a range of 0 - 8，0 mg N with 7 measurements of EDTAstandard (N%=9.57) (Code A00000149) for both carrier gas. The data obtained are included in the tolerance admitted by the EDTA certificate. HELIUM as Carrier Gas ARGON as Carrier Gas Sample quantity (mg) Nitrogen% Sample quantity (mg) Nitrogen % 149.30 2.008 149.30 1.985 149.30 2.014 150.00 2.014 151.40 1.983 151.50 1.990 150.60 1.986 154.50 1.997 148.90 2.006 151.30 2.004 151.20 1.987 148.70 1.984 150.90 1.993 150.50 1.974 149.60 2.007 149.40 1.965 149.00 2.001 149.70 1.964 146.80 1.992 150.10 1.978 Average ± SD 1.998±0.011 1.986±0.016 RSD%* 0.543 0.819 Nitrogen Expected Value： 1.9±0，3% *RSD%=(Standard Deviation*100)/ Average Conclusion Results are extremely reliable and reproducible as demonstrated by the RSD with the same conditions (method and sampleweight) since the goal is to obtain <2.0 % relative standard deviation -as requested by official methods. Helium remains the best choice for premium accuracy but its shortages and interruptions are affecting any related productor instrument， including elemental analyzers. Argon， the best alternative available， has demonstrated to be a validsubstitute， ensuring optimal results. VELP Scientifica NDA 702 Dual Carrier Gas Dumas Nitrogen Analyzer is the perfectresponse to simple， fast and precise nitrogen/protein determination， both with Helium and Argon as carrier gas.       燕麦(Avena sativa)，有时也被称为普通燕麦，是一种谷物，因其种子而生长，它有相同的名字(通常是复数，不像其他谷物和假谷物)。燕麦适合人类食用，如燕麦片和燕麦卷，其中最常见的用途是作为牲畜饲料。燕麦具有降低胆固醇的作用，这使得人们接受它作为一种健康食品。燕麦偶尔也用于几种不同的饮料，例如啤酒或来自拉丁美洲的燕麦饮料。燕麦提取物也可以用于化妆品，传统上，燕麦草被用于医疗目的，包括帮助平衡月经周期，治疗痛经，骨质疏松症和尿路感染。实验样品：Oat Meal Reference Material code A00000318                  氮含量范围: 1.9 ± 0.3 %实验仪器：NDA 702双载气杜马斯定氮仪（意大利velp）参照标准：AOAC 992.23谷物和油籽中的粗蛋白质实验结果：在相同条件下(方法和样品重量)的RSD证明了结果是非常可靠和可重复性的，因为目标是获得官方方法要求的相对标准偏差< 2.0%。Scientifica NDA 702双载气杜马斯定氮仪是简单，快速和精确的氮/蛋白测定的完美响应，以氦气和氩气为载气。