柠檬茶中维生素C含量检测方案(自动电位滴定)

智能文字提取功能测试中

柠檬茶中维生素C含量的测定 应用资料日本农业标准规定了用2,6-二氯靛酚滴定法滴定测定样品中维生素C的定量方法。这种方法以重复性条件下获得的两次独立测定结果的算术平均值表示。本应用使用相同的滴定剂的测量方法。用蓝色的碱性染料2,6-二氯靛酚标准溶液对含L(+)-抗坏血酸的试样酸性浸出液进行氧化还原滴定，2,6-二氯靛酚被还原为无色，当到达滴定终点时，多余的2,6-二氯靛酚在酸性介质中显浅红色，由2,6-二氯靛酚的消耗量计算样品中L(+)-抗坏血酸的含量。TIF-99301enLK-MKYOTO ELECTRONICSMANUFACTURING CO.，LTD. Application MemoVitamin C in Lemon tea Industry Food & beverage Instrument Automatic potentiometric titrator Measurement method Redox titration Standards GB 5009.86 1.Overview Japanese Agriculture Standards specify the quantifying method of the vitamin C in a sampleby titrations using indophenol. But this method has a practical problem of requiring two testswith different titrants. This memo demonstrates the measurement method using a same titrant.First， known concentration L ascorbic acid is titrated with the indophenol solution. The factorof the indophenol solution is calculated from its titration volume. Then add acetic acid to thediluted lemon tea sample and titrate it with same indophenol solution. The vitamin Cconcentration in the sample is calculated from the factor and titration volume of theindophenol solution. 2. Apparatus Main unit Automatic potentiometric titrator (preamplifier STD) Electrode Combined platinum electrode 3. Reagents Titrant Indophenol solution (0.3948g of 2.6-dichlorophenol indophenol dissolvedin pure water， made into total 1000mL)Additive Acetic acid (special grade) 4. Example —Measurement results— Sample Titer Concentration (g) (mL) (%) 1 1.0364 1.4030 0.0367 2 1.0567 1.4295 0.0367 3 1.0290 1.4092 0.0371 Average 0.0368 SD 0.0003 RSD(%) 0.7 -Titration curve一 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