运动蛋白粉中氮检测方案(氮磷钙测定仪)

APPLICATIONNOTEF&F-D-002-2016/A3 NITROGEN DETERMINATION IN SPORT POWDERDUMAS COMBUSTION METHOD Nitrogen Determination in Sport Powderaccording to the Dumas method (He/Ar as Carrier) Reference： ISO 14891：2002 Milk and Milk Products Tested with VELP Scientifica NDA 702 Dual Carrier Gas Dumas Nitrogen Analyzer (Code F30800080) Introduction Bodybuilders may supplement their diets with protein for reasons of convenience， lower cost (relative to meat and fishproducts) and to avoid the concurrent consumption of carbohydrates and fats. Protein supplements are sold in ready-to-drink shakes， bars， meal replacement products， bites， oats， gels and powders. Protein powders are the most popularand may have flavoring added for palatability. The powder is usually mixed with water， milk or juice and is generallyconsumed immediately before and after exercising， or in place of a meal. Different sport powder products were chosen to demonstrate the suitability of the DUMAS method for Nitrogen/ Proteinanalysis by using Helium and Argon as carrier gas. Nitrogen Determination in Sport Powders 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 afterthe combustion， 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 through the intuitive DUMASoft TM. 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 Carrier gas (He/Ar)： 190 ml/min Flow rate MFC2 Carrier gas (He/Ar)： 220 ml/min Condition the system by testing 2 EDTA standard (Code A00000149) and 3 to 5 empty tin foils (Code A00000153) asCheck up. Verify the calibration curve with one or more tests as Standard by testing the same standard used for the curve creation. Sample Preparation Using a spatula， put~ 30-50 mg Sport Powder into the tin foil according to the nitrogen content. 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 ENERGY BAR method shows the following parameters： Protein factor： 6.25 O2 flow rate： 400 ml/min O2 factor：1.8 ml/mg Press to start the analysis. Analysis time： from 3 minutes for one run. Results on Sport Powder Results have been obtained with the following calibration curve： in a range of 0 -90 mg N with 8 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. The table below shows the nitrogen/protein reproducibility of four sport powders analyzed for three consecutive timesusing Helium and Argon as carrier gas and a small sample weight (30-50 mg).The sample weight is always the same with Helium and Argon as carrier gas. HELIUM as Carrier Gas ARGON as Carrier Gas Sample Nitrogen% Protein % RSD% Nitrogen% Protein% RSD% Sport powder 1 13.10313.07213.127 81.89481.70082.221 0.21 13.02413.18813.127 81.40382.42682.046 0.63 Sport powder 2 11.62911.63011.479 72.67972.69071.742 0.75 11.62111.56911.597 72.63372.30572.478 0.22 Sport powder 3 12.002 12.040 12.024 75.011 75.247 75.149 0.15 12.01812.06112.020 75.11075.381 75.128 0.20 Sport powder 4 14.173 14.126 14.110 88.583 88.288 88.186 0.23 14.13614.165 14.073 88.35188.530 87.959 0.33 In order to prove the performance of two different NDA 702 Dumas Nitrogen Analyzer by using helium and argon carriergas， four sport powder samples were analyzed for three consecutive times. HELIUM as Carrier Gas ARGON as Carrier Gas Sample NDA 702_A NDA702_A NDA702_B NDA702_B NDA702_A NDA 702_A NDA 702_B NDA 702_B AverageN% RSD% AverageN% RSD% AverageN% RSD% AverageN% RSD% Sport powder 1 13.09 0.21 13.02 0.55 13.11 0.63 13. 13 0.42 Sport powder 2 11.57 0.75 11.54 0.21 11.59 0.22 11.54 0.88 Sportpowder 3 12.02 0.15 12.00 0.08 12.03 0.20 12.08 0.69 Sportpowder 4 14.14 0.23 14.04 0.08 14.12 0.33 14.01 0.38 Conclusion The determination of nitrogen and protein in sport powder using NDA 702 provides reliable and reproducible results byusing both Helium and Argon as carrier gas. The data confirm the complete combustion of the sample with no memory effect observed when changing sample.Results are extremely reliable， as demonstrated by the RSD， both using helium and argon as carrier gas， with the sameconditions (method and sample weight) since the goal is to obtain < 2.0% relative standard deviation， as requested byofficial methods. Helium remains the best choice for premium accuracy but its shortages and interruptions are affecting any relatedproduct or instrument， including elemental analyzers. Argon， the best alternative available， has demonstrated to be avalid substitute， ensuring excellent results. VELP Scientifica NDA 702 Dual Carrier Gas Dumas Nitrogen Analyzer is theperfect response to simple， fast and precise nitrogen/protein determination， both with Helium and Argon as carrier gas. 出于方便、成本较低(相对于肉类和鱼类产品)以及避免同时摄入碳水化合物和脂肪的原因，健美运动员可能会在饮食中补充蛋白质。蛋白质补充剂以速溶饮料、棒、代餐产品、燕麦片、凝胶和粉的形式出售。蛋白质粉是最受欢迎的，可能添加了调味料，以使其适口。这种粉末通常与水、牛奶或果汁混合，通常在运动前后立即食用，或代替用餐。选择不同的运动粉末产品，以证明使用氦气和氩气作为载气的DUMAS方法对氮/蛋白质分析的适用性。检测样品：运动蛋白粉检测仪器：杜马斯定氮仪NDA702（意大利VELP）参考方法: ISO 14891:2002检测结果：通过以下校准曲线获得了结果:在0 - 90 mg N范围内，对两种载气进行8次EDTA标准测量(N% = 9.57)(代码A00000149)。获得的数据在EDTA证书认可的公差范围中。下表显示了以氦气和氩气为载气，小样本重量(30 - 50 mg)连续分析三次的四种运动粉末的氮/蛋白质的重复性。以氦气和氩气为载气时，样品重量始终相同。为了验证NDA 702杜马斯定氮仪的性能，采用氦气和氩气载气，对四种运动粉末样品进行了连续三次分析。结论：用NDA 702测定运动粉中氮和蛋白质，用氦和氩作载气，结果可靠，重复性好。数据证实了样品完全燃烧，在更换样品时没有观察到记忆效应。结果是非常可靠的，正如RSD所证明的，使用氦和氩作为载气，在相同的条件(方法和样品重量)，因为目标是获得< 2.0%相对标准偏差，按官方方法要求。氦仍然是高精确度的最佳选择，但它的短缺和中断正在影响任何相关产品或仪器，包括元素分析仪。氩气，可用的最佳替代品，已被证明是有效的替代品，确保了优异的结果。VELP Scientifica NDA 702双载气定氮仪是简单，快速和精确的氮/蛋白质测定的完美响应，都以氦和氩作为载气。