This test method covers the determination of dissolved and total recoverable molybdenum in most waters, wastewaters, and brines by atomic absorption spectroscopy. This test method is applicable in the range from 1 to 25 µg/L of molybdenum. The range may be extended by dilution of the sample. This test method has been used successfully with natural and reagent waters. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.