Sampling bias caused by materials used to monitor halocarbons in groundwater

摘要: Laboratory experiments were conducted to evaluate materials used in the construction of groundwater monitors for their potential cause sampling bias. Ten exposed low concentrations five halogenated hydrocarbons water periods up 5 weeks. Borosilicate glass was only material that did not diminish halocarbon concentrations. Three metals, including stainless steel, apparently transformed compounds. Six synthetic polymers, poly(tetrafluoroethylene) and rigid poly(vinyl chloride), absorbed The sorption rates dependent on flexibility polymer, solubility compound, solution volume polymer surface area ratio, temperature. A diffusion model explained concentration histories solutions mechanism confirmed by direct measurement distributions several polymers. experimentally determined diffusivities polymer-water partition coefficients polyethylene consistent with literature data.