Abstract |
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 (AL) for lead at the tap as 0.015 mg/L. Researchers and drinking water utilities typically employ EPA Method 200.8 to quantify lead and other trace metals in drinking water and wastewaters, using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). EPA method 200.8 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 actual 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 by using the standard preservation protocol of the method and varying the water source, bottle type, and preservation pH. Phase Two investigated the recovery of three lead particulates in water samples, by comparing the standard preservation protocol of the method to the more rigorous acid digestion of the method and to an alternative pre-filtration process. |