Reagent Name: Marquis Test
REAGENT PREPARATION
Reagent 1: Add 8-10 drops (approx. 0.25 ml) of 37% formaldehyde solution to 10 ml of glacial acetic acid.
Reagent 2: Concentrated sulphuric acid.
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a depression on a spot plate.
- Add one drop of Reagent 1, then one drop of Reagent 2, and stir.
- Observe the color of the mixture.
Reagent Name: Mecke Test
REAGENT PREPARATION
Reagent: Dissolve 1 g selenious acid in 100 ml conc. sulfuric acid.
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a small test tube.
- Add one drop of Mecke Reagent.
- Observe the color of the mixture.
Reagent Name: Simon’s Test
REAGENT PREPARATION
reagent 1: Dissolve 2 g of sodium carbonate in 100 ml of water
(=2% aqueous sodium carbonate solution).
Reagent 2: Dissolve 0.9 g of sodium nitroprusside in 90 ml of water (=1% aqueous sodium nitroprusside solution).
Reagent 3: Mix 10 ml of acetaldehyde solution and 10 ml of ethanol (=50% (v/v) ethanolic acetaldehyde solution).
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a depression on a spot plate.
- Add one drop of Reagent 1 and stir.
- Add one drop of Reagent 2, and then one drop of Reagent 3.
- Observe the color of the mixture.
Reagent Name: Gallic Acid Test
REAGENT PREPARATION
Reagent: Dissolve 0.1 g of gallic acid in 20 ml of concentrated sulphuric acid (=0.5% (w/v) solution)
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a small test tube.
- Add one drop of Gallic Acid Reagent.
- Observe the color of the mixture.
Reagent Name: Erlich's Test (aka PDMAB Test)
REAGENT PREPARATION
Reagent: Dissolve 0.5 g p-dimethylaminobenzaledehyde (p-DMAB) in 50 ml ethanol and 50 ml conc. hydrochloric acid.
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a small test tube.
- Add one drop of Erlich's Reagent.
- Observe the color of the mixture.
Reagent Name: Chen's Test
REAGENT PREPARATION
Reagent 1: Add 1 ml of glacial acetic acid to 100 ml of water (=1% (v/v) aqueous acetic acid solution).
Reagent 2: Dissolve 1 g of copper (II) sulphate in 100 ml of water (=1% (w/v) aqueous CuSO4 solution).
Reagent 3: Dissolve 8 g of sodium hydroxide in 100 ml of water (=2N aqueous sodium hydroxide solution).
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a depression on a spot plate.
- Add 2 drops of Reagent 1.
- Add 2 drops of Reagent 2, then add 2 drops of Reagent 3 and stir.
- Observe the color of the mixture.
Reagent Name: Mandelin Test
REAGENT PREPARATION
Reagent: Suspend 1 g of finely powdered ammonium vanadate in 100 ml of concentrated sulfuric acid (relative density 1.86).
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a small test tube.
- Add one drop of Mandelin Reagent.
- Observe the color of the mixture.
Reagent Name: Sodium Nitroprusside Test
REAGENT PREPARATION
Reagent 1: Mix 25 ml of a 1% sodium nitroprusside solution with 1 ml acetaldehyde.
Reagent 2: 2% sodium carbonate solution.
PROCEDURE
- Place a small amount (1-2 mg of powder, or 1-2 drops of a liquid) of the suspected material in a depression on a spot plate.
- Add one drop of Reagent 1 and stir.
- Add one drop of Reagent 2.
- The color is formed immediately after Reagent 2 is added.