What applications could a flame test be used for in real life?

Question

What applications could a flame test be used for in real life?

Answer 1

for testing hydrogen...

for testing carbon dioxide..

Answer 2

Inductively coupled plasma spectroscopy (ICP) is an example of a flame test used in real life.  You probably dipped metal ions into flames and they turned green or red or purple.  In ICP spectroscopy a sample is heated to 3000K or some really hot temperature and the sample will emit a specific wavelength of light. The machine has a diffraction grating that separates the wavelengths of light and detects each of them and their intensity.  Therefore you can use ICP to determine what substances are in a sample and how much.  It's used for analyzing things like lead content in drinking water.