Arsenic speciation (arsenite and arsenate) measurement context
EPA Method 1632A, hydride generation with quartz furnace atomic absorption: inorganic arsenic is converted to arsine gas, collected in a cold trap, and measured by atomic absorption in a heated quartz cell. Arsenite (As III) is measured under conditions where arsenate does not react; total inorganic arsenic is measured after the conditions are changed, and arsenate (As V) is the difference. Reported in µg/L. A total arsenic result from the metals tests does not show these forms.
Define the specialty measurement
State the isotope, fiber or chemical-form question as applicable. A total, gross or combined measurement does not automatically answer a species-specific question.
Include the complete project requirement
Provide the matrix, target analytes, required method, fraction, units and reporting limits. Include the permit or monitoring instructions where results will support a regulatory submission. Naming this method does not establish blanket compliance eligibility.
Resolve collection before sampling
Use the bottle, preservation and delivery instructions assigned to the agreed scope. Identify each location and collection time, and document any deviation. The final analytical plan must fit the submitted material and its intended use.
Related testing & guidance
Technical & service references
Vanguard service detailsSource review: November 8, 2026. The agreed method and project scope govern the testing.