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维生素 C 的含量测定

维生素 C 的含量测定. 碘量法. 原理. 1. 指示剂 淀粉指示液. H +. 方法. 2. 取本品约 0.2g ，精密称定，加新沸过的冷水 100ml 与稀醋酸 10ml 使溶解，加淀粉指示液 1ml ，立即用碘滴定液（ 0.05mol/L ）滴定，至溶液显蓝色，在 30 秒内不褪。每 1ml 碘滴定液 (0.05mol/L) 相当于 8.806mg 的 C 6 H 8 O 6. 3. 讨论. （ 1 ）酸性环境. 减慢 VitC 被 O 2 氧化速度. （ 2 ） 新沸冷 H 2 O. 赶走水中 O 2. （ 3 ）立即滴定.

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维生素 C 的含量测定

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  1. 维生素C的含量测定

  2. 碘量法 原理 1. 指示剂 淀粉指示液

  3. H+

  4. 方法 2. 取本品约0.2g，精密称定，加新沸过的冷水100ml与稀醋酸10ml使溶解，加淀粉指示液1ml，立即用碘滴定液（0.05mol/L）滴定，至溶液显蓝色，在30秒内不褪。每1ml碘滴定液(0.05mol/L)相当于8.806mg的C6H8O6

  5. 3. 讨论 （1）酸性环境 减慢VitC被O2氧化速度 （2）新沸冷H2O 赶走水中O2 （3）立即滴定 减少O2的干扰

  6. （4）附加剂干扰的排除 片剂 ——滑石粉 ——过滤 注射剂 ——抗氧剂——丙酮

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