乌梅醋中总酸和氨基酸态氮检测方案(自动电位滴定)

乌梅醋中总酸和氨基酸态氮的测定 应用资料稀释样品用0.1ml/L氢氧化钠滴定至pH8.2和pH9.2。总酸根据滴定曲线上pH8.2终点的氢氧化钠滴定体积计算。将中性甲醛溶液添加到测量样品中后，再次用0.1ml/L氢氧化钠滴定至pH9.2。根据滴定曲线上pH8.2的第二和第三终点处氢氧化钠的滴定体积数据计算氨基酸态氮。KGM KYOTO ELECTRONICSMANUFACTURING CO.，LTD.TIF-98002enLK-MKYOTO ELECTRONICSMANUFACTURING CO.，LTD. Application Memo Total Acids and Amino Acid of Ume Plum Vinegar IndustryFood & beverageInstrumentAutomatic potentiometric titratorMeasurement methodAcid-base titrationStandardsGB 5009.235 1.Overview The diluted sample is titrated with 0.1ml/L sodium hydroxide up to pH8.2 and pH9.2. Thetotal acidity is calculated from the titration volume of sodium hydroxide at pH8.2 endpoint onthe titration curve. After adding the neutral formalin to the measured sample， it is titrated with0.1ml/L sodium hydroxide up to pH9.2 again. The amino acidity is calculated from thetitration volume data of sodium hydroxide at second and third endpoints at pH8.2 on thetitration curve. 2. Apparatus Main unit Automatic potentiometric titrator (preamplifier STD) Electrode pH Glass electrode Ceramic reference electrode Temperature compensation electrode 3. Reagents Titrant 0.1mol/L sodium hydroxide Solvent Pure water Additive Neutral formalin 4. Example Sample Titer1 Titer2 Titer3 Total Amino (mL) (mL) (mL) (mL) Acidity Acidity 1 10.0732 10.3905 11.2679 50.37 4.387 2 10.0 10.0748 10.3992 11.2990 50.37 4.499 3 10.0860 10.4148 11.3049 50.43 4.451 Average 50.39 4.446 SD 0.035 0.056 RSD(%) 0.069 1.3 Titration curve Please feel free to contact us for any further information. Kyoto Electronics Manufacturing Co.， Ltd. Overseas Sales & Marketing Sect. 京都电子工业株式会社-可睦电子(上海)商贸有限公司 上海市徐汇区宜山路333号1201室 电话： 021-54488867 电邮： kemu-kem@163.com 网址： http：//www.kem-china.com