How can you test for the decreased gas in the laboratory?

One way to test for decreased gas in the laboratory is to use a gas sensor or gas detector. These devices can measure the concentration of specific gases in the air and can detect if there is a decrease in the levels of a particular gas. Another method is to use gas chromatography, which can separate and analyze the components of a gas sample to determine if there has been a decrease in a specific gas. Additionally, you can use chemical indicators or reagents that change color in the presence of certain gases to visually detect a decrease in gas levels.