Name two EPA methods commonly used for VOCs in groundwater.

• A. EPA Method 8270 and 8240.
• B. EPA Method 8240 and 8260.
• C. EPA Method 8260 and 8260B.
• D. EPA Method 8243 and 8260.

Answer: (C)

VOCs in groundwater are most reliably measured with GC–MS because these compounds are volatile and often present at trace levels in water, so a method that separates by gas chromatography and confirms identity with mass spectra is ideal. EPA Method 8260 is the standard GC–MS method for volatile organics in water, providing identification and quantitation across a wide range of VOCs commonly found in groundwater. The updated version, 8260B, preserves the same target list and core approach but includes refinements in instrument conditions, QA/QC, calibration, and robustness for modern GC–MS systems. In practice, labs use 8260B for new analyses and 8260 for legacy data, ensuring consistency and comparability over time. These two together are the go-to pair for VOCs in groundwater because they are specifically designed for water matrices and widely adopted across laboratories.