尿素水溶液中折光率和浓度检测方案(折光仪)

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京都電子工業株式会社KYOTO ELECTRONICSMANUFACTURING CO.，LTD.APRA-0143en APRA-0143en7.Calculation Application Note Refractive index and urea content of AdBlueR Industry ChemicalsInstrument RefractometerMeasurement method Detection of critical angle of optical refractionStandards GB 29518， ISO 22241， JIS K2247 1.Scope Refractive index and urea content ofAdBlueR were determined based on “ISO 22241 Dieselengines -NOx reduction agent AUS 32 -. First，refractive indexes of urea standard solution at a concentration of 30-35% were measured，and calibration curve of refractive index and urea concentration was prepared. Then， refractiveindex of a sample was measured， and urea content was calculated by using the calibration curve.The calculated urea content was corrected by deducing biuret content of the sample determined byspectrophotometry. 2.Precautions 1) Perform a calibration with air and pure water before measurement. 3.Post-measurement procedure 1)Wash the prism surface of refractometer with pure water and wipe it. 4.Apparatus Main unit Refractometer 5. Reagents Urea standard solution (concentration ：30.0，31.5，32.5，33.5，35.0mass%) These solutions were prepared by dissolving urea dried at 105°℃ for 2 hours in pure water. 6.Procedure -Measurement- 1) Set the measuring temperature of the main unit to 20°C， and wait until it is stabilized. 2) Perform a calibration with air and pure water. 3) Drip the standard solution or the sample on the prism surface， and close the cover. 4)Start a measurement. 5) Wash the prism surface with pure water and dry it. 上海市徐汇区宜山路333号1201室网址： http：//www.kem-china.com -Evaluation factor- 2i=1Wui2i=i(nui-nw)F Evaluation factorWU，i Urea content of standard solution (mass%)nu，i Refractive index of standard solutionnw Refractive index of water= 1.33299 -Urea content- WuUrea content of sample (mass%)npRefractive index of samplenwRefractive index of water=1.33299FEvaluation factorWBiBiuret content of sample*=0.11(mass%) *1 Biuret content of sample was separately determinedby spectrophotometry. Biuret forms in alkalinesolution in the presence of sodium-potassium-tartratewith bivalent copper a complex with an absorptionmaximum at 550 nm. This complex was readspectrophotometrically at 550 nm and the biuretconcentration was determined by reference to acalibration curve prepared from standard biuretsolutions. *2 The limit value of biuret content is below 0.3 mass%. 8. Example -Parameter- Temp. Comp.：：Off (This parameter is an example of our refractometer. For other models， parameter items may bedifferent or other items may be added.) -Measurement results- Preparation of calibration curve Measurement results of refractive index of urea standard solution and calibration curve areshown in Table 1 and Fig. 1 respectively. The evaluation factor was calculated to be 655.29. Table 1 Measurement results of urea standard solution Urea content Refractive index (mass%) 2 Mean 29.97 1.37850 1.37850 1.37850 31.45 1.38087 1.38087 1.38087 32.47 1.38254 1.38254 1.38254 33.48 1.38417 1.38417 1.38417 34.99 1.38664 1.38664 1.38664 Fig. 1 Calibration curve Measurement of sample Measurement results of refractive index and urea content of sample are shown in Table 2. Table 2 Measurement results of sample Refractive index Urea content (-) (mass%) 1.38321 32.80 2 1.38322 32.81 Mean 1.38322 32.81 Repeatability* 0.00001 0.01 *Repeatability means the difference of the two resultsS. 9. Summary As the measurement results of refractive index and urea content of AdBlueR， bothrepeatabilities were within the limit (Refractive index ： 0.0001， Urea content ： 0.1) specified bythe ISO and JIS standards， and both results satisfied the quality requirements (Refractive index ：1.3814-1.3843， Urea content ： 31.8-33.2). When actually measuring， please refer to the latest standards. 10.References 1) ISO 22241 ：2006(E) IDiesel engines-NOx reduction agent AUS 32- 2) JIS K2247 ： 2009 Diesel engines-NOx reduction agent AUS 32- 都電子工業株式会社KYOTO ELECTRONICSMANUFACTURING CO.，LTD 尿素的折光率和尿素浓度测定 应用资料(英文版)根据GB 29518-2013 柴油发动机氮氧化物还原剂 尿素水溶液(AUS 32)和ISO 22241-2，使用全自动折光率仪测量尿素水溶液折光率和尿素浓度的应用资料。首先，测定浓度为30~35%的尿素标准溶液的折光率，并制备了折射率和尿素浓度的校准曲线。然后，测定样品的折光率，并利用校准曲线计算尿素含量。