GB/T 21242-2019Fireworks—Test methods of qualitative determination of prohibitive and limitative substances (English PDF)

4.1 Sample preparation

4.1.1 Dissection

4.1.1.1 According to the product's nominal single-piece (dose), randomly select the single-piece (dose) sample for dissection; take 10 pieces (doses) if the dose is less than 2 g; take 5 pieces (doses) if 2 g < dose <= 25 g; take 3 pieces (doses) if the dose is more than 25 g.

4.1.1.2 Remove the fuse, detonating fuse head or friction head; respectively, dissect and separate the powder, granular or mass pyrotechnic powder; after the drugs of fuse, detonating fuse head or friction tip are dissected and separated, reserve them separately.

4.1.1.3 For cherry bombs and cracker snaps, remove the outer paper, plastic tubes and other inert materials; take out the pyrotechnic powder part for use.

4.1.2 Smash

5.1 Chlorate

pink, then purple, and dark blue after diffusion, it indicates that there is chlorate. The detection limit of trace impurities is 0.1%. […]

5.2 Lead compounds

Pipette 1 mL of 4.3 spare filtrate into a test tube; add 2 drops of potassium chromate (3.5). If there is a yellow precipitate, which can be dissolved in excess sodium hydroxide (3.6) or nitric acid (3.7), it means there are lead compounds. The detection limit of trace impurities is 0.1%.

5.3 Arsenic compounds

5.3.1 Wet the lead acetate (3.8) for absorbent cotton; dry it; store it in a closed bottle.

5.3.2 Weigh 1.25 g of mercuric bromide (3.9); dissolve in 25 mL of ethanol (3.10); put the ash-free filter paper into the solution and soak for 1 h; take it out; dry it in a dark place; store it in a closed brown bottle.

5.3.3 Pipette 1 mL of 4.3 spare filtrate into a test tube; add 6 mL of hydrochloric acid (3.2); shake well and let stand for 10 minutes; add 1 g of potassium iodide (3.11) and 0.2 mL of stannous chloride dihydrate (3.12); add 2.5 g of zinc granular free from arsenic (3.13); insert the lead acetate (5.3.1) into the test tube; immediately use a mercury bromide test paper (5.3.2) to cover the mouth of the test tube. If the test paper has yellow spots, it means that there are arsenic compounds. The detection limit of trace impurities is 0.1%.

5.4 Mercury compounds

5.4.1 Mix potassium iodide (20%) and sodium sulfite (3.14) in a volume of 1:1; prepare when used.

5.4.2 Pipette 1 mL of 4.3 spare filtrate into a test tube; add 1 mL of potassium iodide and sodium sulfite mixture (5.4.1); add 2 drops of copper sulfate (3.15). If orange-red precipitation is formed, it means that there are mercury compounds. The detection limit of trace impurities is 0.1%.

5.5 Phosphorus

Weigh 0.1 g of sample into a 250 mL beaker; add 5 mL of nitric acid (3.7); heat to dissolve; filter; take 1 mL of filtrate in a test tube; add 5 drops of nitric acid (3.7) and 0.5 mL of ammonium molybdate (3.16); shake well; let stand for 10 minutes. If a yellow precipitate is produced, it means that there is phosphorus. The detection limit of trace impurities is 0.1%. […]

5.6 Magnesium powder