EFFECT OF VARIOUS MATERIALS IN MULTILEVEL SAMPLERS ON MONITORING COMMONLY OCCURRING AGRICHEMICALS IN-GROUND WATER

Studies have shown that materials, such as polytetrafluoroethylene (PT FE), rigid polyvinyl chloride (rigid PVC), flexible polyvinyl chloride (flexible PVC), stainless steel (SS), low-density polyethylene (LDPE) , and high-density polyethylene (HDPE), have the potential to influenc e certain analyte concentrations in ground water samples. The effects of HDPE, LDPE, PTFE, rigid PVC, and SS on aqueous concentrations of ni trate-N, atrazine, deethylatrazine (DEA), and deisopropylatrazine (DIA ) were evaluated in a field study. A laboratory study was conducted to evaluate sorption of atrazine, DEA, DIA, cyanazine, alachlor, metolac hlor. and butachlor to PTFE, HDPE, and SS materials. Butachlor is rare ly used in the United States, but was included because of its expected high sorptivity. No significant differences between HDPE, LDPE PTFE, rigid PVC, and SS were determined for any of the analytes tested in th e field study. In the laboratory study, sorption of DIA to PTFE and SS was significant at 2.6 x 10(-5) and 4.1 x 10(-5) mu g/m(2), respectiv ely. Sorption of DIA to HDPE was not significantly > 0; sorption of al l other compounds to HDPE, PTFE, and SS were also not significantly > 0. Results of the two studies indicate that for these analytes (relati vely polar or ionized compounds), representative ground water samples are not dependent on the materials used for multilevel sampler constru ction. When considering these compounds, it appears that the least exp ensive materials (HDPE, rigid PVC, and LDPE) are good choices for the construction of ground water monitoring wells.