The latest national standard GB5009.228-2016 method for the determination of volatile base nitrogen in food, the most interesting thing is that in this method, the automatic Kjeldahl method is added as the second method. How to correctly understand and apply the article The second method is discussed, and how to determine the content of volatile base nitrogen in the food and the analysis parameter setting using a fully automatic nitrogen analyzer. 1. Sample pretreatment: In the first method, the sample is treated with 100 ml of magnesium trichloride, and it needs to be filtered after standing for 15 minutes. In the second method, the sample containing solid can be used due to the use of the fully automatic Kjeldahl analyzer. Direct analysis eliminates the need for magnesium chloride to process the sample and eliminates the need for a filtration process. 2. Magnesium oxide addition: In the first method, 5 ml of magnesium oxide suspension is required; in the second method, since the distillation tube of the automatic Kjeldahl nitrogen analyzer is 750 ml, 1.0 g of magnesium oxide solid is directly added, and no oxidation is required. Magnesium suspension. 3. Distillation setting: In the first method, the steaming intensity of the manual instrument is weak, the distillation time is 5 minutes; and in the second method, 10.1.4 requires a distillation time of 180 seconds or a distillation volume of 200 ml, whichever comes first. 4. Concentration of standard titration solution: 0.0100 mol/L solution was used in the first method; 0.1000 mol/L solution was used in the second method. 5. Results unit: mg/100g or mg/100ml. Sweden OPSIS has 30 years of experience in Kjeldahl, and its fully automatic Kjeldahl KD-310 has been fully optimized for the national standard GB5009.228-2016, without hardware changes, allowing operators to use it. Very convenient. 1. Set two kinds of titration end point judgment methods: effluent volume + color end point judgment or distillation time + color end point judgment; directly set the distillation time in the program for 180 seconds to complete, the instrument automatically deducts the time of adding reagents, no need for labor Estimate. 2. Two titration modes are set: titration of normal samples and titration of ultra-low sample. Since the content of volatile base nitrogen in most foods is relatively low, the titration volume is generally <1.0 ml, and the titration of ultra-low sample is used. Mode, which maintains the highest titration accuracy throughout the analysis. 3, titration accuracy: minimum titration accuracy of 1.95 microliters / step, the world's highest precision to date, to ensure the accuracy of the results. 4. Titration process: titration while distillation, when the distillation is finished for 180 seconds, the titration process liquid is completed, which greatly saves time and provides analysis efficiency; at the same time, the titration volume and the nitrogen content in the sample are displayed in real time during the titration process. 5. Result unit: mgN/100g and mgN/100ml are added to the menu. A total of more than 20 result units are available for users to avoid errors caused by unit conversion. Jiasheng (Hong Kong) Technology Co., Ltd. 2017-7-26 Ningbo Nutrition Food Technology Co.,ltd. , https://www.collagenworkshop.com