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实验二 . 叶绿素含量的测定

实验二 . 叶绿素含量的测定. 一 . 实验原理. 叶绿素 a 、 b 在长波的最大吸收峰分别在 663nm 、 645nm ,据 Lamber-Beer 定律,可得浓度 C 与光密度 D 间的关系式: D 663 =82.04C a +9.27C b D 645 =16.75C a +45.6C b ( 浓度单位: g/mL ) C A = 12.72D 663 – 2.59D 645 C B = 22.88D 645 – 4.68 D 663

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实验二 . 叶绿素含量的测定

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  1. 实验二. 叶绿素含量的测定

  2. 一.实验原理 叶绿素a、b在长波的最大吸收峰分别在663nm、645nm,据Lamber-Beer 定律,可得浓度C与光密度D间的关系式: D663=82.04Ca +9.27Cb D645=16.75Ca +45.6Cb (浓度单位:g/mL) CA= 12.72D663 – 2.59D645 CB= 22.88D645 – 4.68 D663 CT = 20.29D645 +8.02D663 (浓度单位:mg/L)

  3. 二. 试剂与材料 2.1 试剂: 丙酮、石英砂、碳酸钙 2.2材料: 水稻、玉米、花生、桑树等植物的新鲜叶片。 2.3 仪器与器皿: 分光光度计、台秤、剪刀、研钵、移液管、漏斗、大试管

  4. 三. 实验步骤 叶片洗净、吸干、去大叶脉 ↓ 称0.5g叶用丙酮研磨 ↓ 匀浆过滤(用80%丙酮洗研钵及残渣,合并滤液) ↓ 滤液用80%丙酮定容至10mL ↓ 适当稀释后测A645、A663

  5. 四. 结果计算 4.1 结果计算 C(mg/L)×提取液总量(L)×稀释倍数 Chl = (mg/g叶) 材料鲜重(g) 4.2 比较分析不同植物的叶绿素含量差异及同种植物在不同生长环境下Chla/Chlb差异。

  6. 五. 注意事项 • 注意叶绿素一定要提干净,避免造成测定误差 • 叶绿素初提液体积不要太多,以免浪费试剂,如果浓度太高可进行适当稀释 • 注意分光光度计的规范使用

  7. 六. 思考题 • 为什么植物在不同生长环境下其 Chl含量有差异? Chla /Chlb有何适应意义?

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