食品中氯离子或氯化钠（盐）含量检测方案(自动电位滴定)

Analysis And Testing TechnologyApplication Julabo VISCOAnalysis And Testing Technology Application Use Potentiometric determination of chloride/sodium chloride ("salt") in food samples such as salt， spice mixtures，cheese， meat or tomato sauce. Appliances Titrator： TitroLine 6000/7000/7750 Burette： WA 20 (or WA 10， WA 50) Stirrer： TM 235 Electrodes Electrode： AgCI 62 (with cable L 1 A) or AgCl 62 RG Electrolyte： KCI 3 mol/L (not for AgCI 62 RG) Reagents Solvent： distilled water Titration agent： silver nitrate solution (AgNO3) 0.1 mol/L Standard： NaCl titrimetric standard HNO3 1 mol/l Description Preparation of the silver nitrate solution Please use for the 0.1 molar solution a ready prepared commercial solution. Application Connect the Ag type electrode with the electrode cable at the electrode plug of the TitroLine6000/7000/7750. Open the refilling hole of the electrode (only AgCl 62). Standard titration For a standard titration weigh in 70-90 mg of the NaCl standard in a 150 ml beaker， add appr. 80 ml dist.water and 1 ml HNO3 1 mol/l. Place the electrode and burette tip in the sample and start the method. Thetitration should stops at the equivalence point. ((W*F2)/((EQ1-B)*M*F1) W= weight of the NaCl standard in g F1=1 F2=1000 Conversion factor of mg to g B=0 Blank value The result is the calculated as mol/l and can be automatically transferred into the interchangeable unitWA20： GLP cocumentation Tiration graiph ·myml dmWdmi Hethod daa Method name：Titre AoNO3Ttration duration：3m4sEnd date：11.01.13End time：18：27：02Tilralion dataWeight：0.58660 gStartmy：19.7myEnd my：255.4myEQ：10.024 ml/201.7mVTte：0.1001 moll (W*F2)/((EQ1-B)*M*F1)->WA Mol (M： 58.44000 Sample chemical equation： Ag++CI→→/AgC/ ↓ calculation： (EQ1-B)*T*M*F1/(W*F2) EQ1： ml consumption at the equivalence point B=0 Blank value T= exact concentration of the titrant in mol/l (c *factor) M= molecular/equivalent weight of NaCl or Cl F1=0.1 conversion factor for%(*100/1000) W= weight of the sample in gram F 2= 1 Weigh about 0.05-10 g (please refer to the table) in a 150 ml glass beaker， dilute the sample with dist.water up to 80 - 100 ml and add 1 ml of HNO3 1 mol/l. Place the electrode and burette tip in the sample andpress the "START” key. The titration stops at the equivalence point. The result can be read from the displayor is printed on the connected printer. Cheese samples， butter or other solid food products： Weigh the sample in a 150 or better 250 glass beaker and add 100 ml hot water (55℃). For butter bolingwater is recommended. It is also recommended to use a homogenisator for the better extraction of the NaClfrom the sample. Add 1 ml HNO3. The warm/hot sample can be titrated directly. Sample amount using a 0.1 m AgNO3： Salt content appr. sample weight <0.1% >10 g 0.1-1% 1-10g 1-10% 0.1-2g 10-50% 0.05-0.1g 50-100% 0.05g Application Result example ： GLP documentation Titation aranh %m2000n Method name： Salt in % Titration duration： 2m 10s End date： 07.03.13 End time： 16：46：19 Titration data Sample ID： Salted Butter 2 Weight： 2.93600 g Stait mV： 49.7 mV End mV： 225.9 mV EQ： 8.361 ml / 200.8 mV Salt： 1.66 % Caloulation formula Salt： (EQ1-B)*T*M*F1/(W*F2) Mol (M)： 58.44300 Blank value (B)： 0.0000 ml Tite (T)： 0.10000000 (a) Factor 1 (F1)： 0.1000 Weight (W)： 2.93600g(m) Factor 2 (F2)： 1.0000 Statistics： Of Application Method Method data overall view Method name： Sat in% Created at： Method type： Automatic titration Last modification： Measured value： mV Titration mode： Dynamic Documentation： GLP Dynamic： Steep Measuring speed / drift： User-defined： minimum holding time：03 s maximum holding time： 15s Measuring time： 03 5 Drift： 10 mV/min Initial waiting time： 0s Titration direction： Increase Pretitration： End value： EQ： Slope value： User-defined Value： 200 Dosingparametec Dosing speed： 100.00 % Filling speed： 30 s Maximum dosing volume： 50.00 ml Unit walues Unit size： 20ml Unit ID： 1296649042 Reagent： AgNO3 0.1 mol/L Batch ID： Any Comment Concenbration [mol/l]： 0.10000 Dtermined at： 01/18/13 23：13：00 Expire date： 12/31/12 Opened/compounded： 08/19/11 Test according ISO 8655： 01/01/00 Last modification： 02/15/13 9：54：17 Hints lf you have any questions on the application， you can feel free to contact us.. JULABO TECHNOLOGY(Beijing)Co.，LTD 地址：北京市朝阳区酒仙桥东路1号院M8号楼C厅3层301室 Add ： Room 301，C hall，M8 office building，No.1 jiuxianqiao east road ，Chaoyang District，Beijing，China 公Tel.：4008092068 Fax： +86 (0)10 64390585 品E-Mail ： info@julabo.cn ③Web： www.julabo.cn， www.julabo-visco.com 优莱博技术(北京)有限公司 Page of Date： Page of Date：