EPA Mercury Sampling

EPA Method 1631 (Water)
This method detects ultra-trace levels of mercury in water using oxidation, purge & trap, and Cold Vapor Atomic Fluorescence Spectroscopy (CVAFS). It is widely applied for monitoring drinking water, rivers, lakes, and wastewater.

Clean Hands/Dirty Hands (Method 1669)
A strict sampling protocol where one sampler only touches clean surfaces ('clean hands') while another handles equipment ('dirty hands'). This reduces the risk of contaminating trace-level mercury samples in the field.

Solid Samples (Methods 7471B & 7473)
Method 7471B uses a manual cold-vapor technique for mercury in soils, sediments, and sludge, while Method 7473 directly analyzes solid samples without lengthy preparation. Both ensure accurate testing of contaminated land and waste.

Air Sampling
Mercury in air is collected with sorbent traps or gold-coated traps that capture vapor for later lab analysis. The captured mercury is then measured with Cold Vapor Atomic Absorption/Fluorescence methods to monitor industrial emissions and workplace exposure.

Quality Control
EPA requires blanks, duplicates, and spiked samples to check for contamination, precision, and accuracy. These quality assurance steps ensure that mercury data is scientifically valid and legally defensible.