Sulfuric acid tests are used in many industries. Any tests that use sulfuric acid as the main ingredient are sulfuric acid tests. The Gerber Butterfat test is a sulfuric acid test to determine the fat content and quality of milk. Aromatic compounds, like benzene, can be poisonous and cancerous, but there are very easy sulfuric acid tests to determine if any substance contains these compounds. Halide ions can be identified with sulfuric acid tests, but usually silver nitrate tests produce better results.
In the perfume industry, aromatic compounds are used to provide a strong fragrance. To test new substances for aromatic compounds, the fuming sulfuric acid test is used. The fuming sulfuric acid test requires mixing concentrated sulfuric acid with a small sample of the substance that needs to be tested for aromatic compounds. This helps determine if the substance is very reactive with sulfuric acid or not. If it mixes completely, then other tests should be considered, because adding the substance to fuming sulfuric acid, or sulfuric acid pumped with sulfuric trioxide gas, could cause an explosion.
Other substances that do not mix well in the first test are added to fuming sulfuric acid and the results are monitored closely. Substances that contain aromatic compounds will quickly mix in the fuming sulfuric acid. After a couple of minutes, the mixture should increase in heat and form black flakes from the burning of the new compounds.
Milk companies use sulfuric acid tests to determine the quality and value of the milk being produced at a certain location. The Gerber Butterfat test uses sulfuric acid and amyl alcohol mixed with a fresh milk sample to determine the quality and amount of butterfat. In the milk industry, testing is done with precise measurements and temperatures for quality control and comparing with other milk tests. The basic concept can be shown without those precise numbers as long as the ratios are kept the same.
To perform a basic Gerber Butterfat test, sulfuric acid and milk are first added in equal parts in a special container called a butyrometer. A very small amount, perhaps as little as a single drop, of amyl alcohol is also added, and the container is spun at high speeds in a centrifuge. This separates the butterfat from the rest of the fluids. A good milk sample separates distinctly into a straw colored top half and a colorless bottom half, which allows testers to read the exact measurements of butterfat in the container.