The invention relates to detection gel, and in particular to one-component gel for detecting
formaldehyde in air and water solutions, which is applicable to the field of environment detecting. A preparation method of the gel is as follows: taking 99
mass parts of
distilled water, heating to 85 DEG C, adding 1
mass part of
basic fuchsin, and stirring. The gel for detecting the
formaldehyde in the air and the water solutions is characterized in that the preparation method comprises the following steps: taking 5
mass parts of 1%
basic fuchsin solution, adding 70 to 80 mass parts of
distilled water, starting stirring, then adding 10 mass parts of 10%
sodium sulphite solution, adding 10 mass parts of 4%
sulfuric acid solution, adding 0.1 to 0.5 mass part of
active carbon, stirring, standing, and filtering to obtain a colorless and transparent detection
reagent for later use; taking 70 mass parts of the detection
reagent, adding 0.3 to 10 mass parts of thickening gel, uniformly stirring and dispersing, so as to obtain a detection solution for later use; then taking 0.1 to 0.5 mass part of
polyamino acid coenzyme to be dissolved in 10 mass parts of
distilled water, gradually dropwise adding an obtained solution into the detection solution, and gradually gelling the solution to a paste, adding distilled water to 100 mass parts, uniformly stirring, thus obtaining the
toothpaste-shaped
formaldehyde-detecting gel.