ルミノールによる化学発光

熱なしに化学反応で青い光を生み出す

Classroom Demonstrations Intermediate (High School) 30 分 ~$15.00

目的

触媒の存在下で過酸化水素によりルミノールを酸化し、可視青色光を生成することで化学発光を実証する。

背景

Luminol (3-aminophthalhydrazide) produces an eerie blue glow when oxidized by hydrogen peroxide in basic solution with a transition metal catalyst. The oxidation produces 3-aminophthalate in an excited electronic state, which releases energy as a photon of blue light (425 nm) as it returns to the ground state. This is the same reaction used by forensic scientists to detect trace amounts of blood at crime scenes, where the iron in hemoglobin acts as the catalyst.

安全上の警告

  • NaOH is corrosive — handle with care
  • Potassium ferricyanide is harmful if ingested
  • Perform in a dark room for best effect
  • Do not mix stock solutions until ready to demonstrate

必要なPPE

goggles gloves lab_coat

材料

  • Luminol (0.5 g)
    3-aminophthalhydrazide
  • Sodium hydroxide (NaOH) (5 g)
    To make solution basic
  • Hydrogen peroxide (3%) (50 mL)
    Household concentration
  • Potassium ferricyanide (K₃[Fe(CN)₆]) (0.5 g)
    Catalyst
  • Distilled water (500 mL)

器具

Beakers (500 mL, 2) Spiral glass tubing or clear tubing Dark room or blackout curtains Magnetic stirrer (optional)

手順

1

Prepare Solution A: Dissolve 0.5 g luminol and 5 g NaOH in 250 mL distilled water.

5 分 NaOH is corrosive
2

Prepare Solution B: Dissolve 0.5 g K₃[Fe(CN)₆] in 250 mL of 3% H₂O₂.

5 分
3

Darken the room completely. Allow eyes to adjust for 1–2 minutes.

2 分
4

Pour both solutions simultaneously into a large beaker or through spiral glass tubing. A bright blue glow appears immediately.

3 分
5

Observe the glow lasting for several minutes. Stirring or agitation renews the glow by mixing fresh reactants.

10 分
6

Discuss the mechanism: luminol oxidation → excited 3-aminophthalate → photon emission (425 nm). Compare with bioluminescence and fluorescence.

5 分

予想される結果

A vivid blue glow appears when the solutions are mixed. The light intensity peaks immediately and fades over several minutes. The glow is bright enough to read by in a completely dark room.

後片付け

The spent solution is relatively non-toxic. Pour down the drain with copious water. Rinse all glassware.

詳細

カテゴリ
Classroom Demonstrations
難易度
Intermediate (High School)
所要時間
30 分
推定費用
$15.00
ステップ数
6
材料
5

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Frequently Asked Questions

What is the objective of ルミノールによる化学発光?
触媒の存在下で過酸化水素によりルミノールを酸化し、可視青色光を生成することで化学発光を実証する。
How difficult is ルミノールによる化学発光?
This experiment is rated as Intermediate (High School). It takes approximately 30 minutes to complete.
What safety precautions are needed for ルミノールによる化学発光?
Key safety precautions include: NaOH is corrosive — handle with care; Potassium ferricyanide is harmful if ingested; Perform in a dark room for best effect.
What materials are needed for ルミノールによる化学発光?
The main materials required are: Luminol, Sodium hydroxide (NaOH), Hydrogen peroxide (3%), Potassium ferricyanide (K₃[Fe(CN)₆]), Distilled water.
What results should I expect from ルミノールによる化学発光?
A vivid blue glow appears when the solutions are mixed. The light intensity peaks immediately and fades over several minutes. The glow is bright enough to read by in a completely dark room.