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Effectiveness of the Preservation Protocol within the Environmental Protection Agency (EPA) Method 200.8 for Soluble and Particulate Lead Recovery in Drinking Water
Citation:
Haas, C., L. Koch, K. Kelty, D. Lytle, AND S. Triantafyllidou. Effectiveness of the Preservation Protocol within the Environmental Protection Agency (EPA) Method 200.8 for Soluble and Particulate Lead Recovery in Drinking Water. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-13/222, 2013.
Impact/Purpose:
To inform the public on drinking water research.
Description:
Lead (Pb) is a toxic trace metal that is regulated in drinking water. The U.S. Environmental Protection Agency (USEPA) issued the Lead and Copper Rule (LCR), which defines the action level for lead at the tap as 0.015 mg/L. Researchers and drinking water utilities typically employ EPA Method 200.8 to quantify such trace metals in drinking water (and wastewaters), using Inductively Coupled Plasma-Mass Spectrometry. This method instructs how to properly preserve and analyze a water sample after collection. Recently, researchers have raised concerns about the preservation protocol, and its effectiveness in recovering true concentrations of particulate lead in water samples. Specific concerns with the acidification protocol include bottle types, and occurrence of lead particulates in water samples. To investigate these concerns, a two-phase study was performed. Phase one investigated the recovery of dissolved lead in water samples using the standard preservation protocol of the method, depending on different water sources, bottle types, and preservation pHs. Phase two investigated the recovery of three lead particulates in water samples using the standard preservation protocol of the method, versus the more rigorous acid digestion procedure of the method and an alternative prefiltration process. Results of Phase 1 showed that soluble lead losses to unpreserved glass bottles were large, while very little loss to unpreserved HDPE bottles wasobserved. Proper preservation rapidly recovered “lost” lead in both bottle types. The particulate findings of Phase 2 indicated that the rigorous acid digestion procedure was effective, but difficult to consistently implement with some lead particulates. These findings aid in determining the effectiveness of the EPA sample preservation protocol detailed in Method 200.8.