Which two methods are commonly used for environmental monitoring of metals?

• A. ICP-OES and GC.
• B. Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
• C. pH meter and ORP sensor.
• D. UV-Vis spectrophotometry and liquid chromatography.

Answer: (B)

Metals in the environment are usually quantified with techniques that specifically identify and measure elemental concentrations at very low levels. Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are built for this purpose. AAS works by atomizing the sample and measuring how much light is absorbed by those atoms at characteristic wavelengths, giving reliable, element-specific concentrations and is cost-effective for routine checks of several metals. ICP-MS, on the other hand, sends the sample into a plasma to ionize atoms and then detects them by mass spectrometry, enabling simultaneous multi-element analysis with extremely low detection limits and even isotopic information. Together, they cover a broad range of metals with both practicality and high sensitivity, which is why they’re widely used in environmental monitoring. The other methods shown are more suited to organic compounds, general water quality parameters, or speciation rather than direct metal quantification, so they don’t fit as well for monitoring metal concentrations.