Buborékteszt

Buborékteszt (bubble test) is a simple qualitative method used to detect gas production in a reaction. The test is applied in chemistry, microbiology, and geology to observe effervescence—bubbles formed as a gas is evolved. It can be performed in various setups, ranging from a simple open test tube to a closed system with a gas-collection device such as a water-filled U-tube or a gas syringe. In many educational and diagnostic contexts, a fixed amount of sample is placed in an appropriate liquid or medium and observed for bubble formation under stated conditions (temperature, time). If gas is produced, visible bubbles appear; the amount of gas can be estimated by measuring collected volume over time.

Common examples: in chemistry, reacting an acid with a carbonate-containing sample releases CO2 and causes fizzing; in microbiology, carbohydrate fermentation by microbes can produce gas trapped in a Durham tube, indicating fermentation activity; in geology or mineralogy, acidic dissolution of carbonate minerals yields visible effervescence.

Interpretation and controls: the presence of bubbles indicates gas evolution but not its identity; controls are needed to exclude air contamination and to account for gas dissolution. Temperature influences bubble formation and gas solubility; in quantification, calibrated collection devices yield gas volumes and rates.

Etymology: the term derives from the Hungarian buborék, meaning bubble, with teszt meaning test.

See also: gas evolution, fermentation test, acid test for carbonates.