Sampling Trace-Level Organics with Polymeric Tubings. Revision
Abstract
There is concern whether tubings used to sample groundwater can affect contaminant concentrations. Tubings might sorb contaminants, thereby giving falsely low values, or they might leach contaminants, thereby giving falsely high values. There also is concern that a tubing used previously in a well with high concentrations of contaminants might subsequently desorb contaminants into samples taken from other wells if decontamination is insufficient. Our review of the literature indicated that these concerns are valid, although a comprehensive study of this subject does not exist. In our laboratory study, we looked for sorption of a suite of organic solutes by 20 polymeric tubings under static conditions. Seven of these tubings were flexible and the others were rigid. We found that among the rigid tubings tested, the three fluoropolymers (fluorinated ethylene propylene (FEP), FEP-lined polyethylene, and polyvinylidene fluoride (PVDF) were the least sorptive tubings. However, even these tubings readily sorbed some of the analytes. Among the flexible tubings tested, a fluoroelastomer tubing and a tubing made of a copolymer of vinylidene fluoride and hexafluoropropylene (PVDF-HFP) were the least sorptive. We also found that several of the 20 tubings appeared to leach constituents into the test solution. We were unable to detect any evidence that constituents leached from the polyethylene tubings, the rigid fluoropolymer tubings, and one of the plasticized polypropylene tubings. Currently, we are conducting studies to see whether the effects we observed in this study increase, decrease, or remain the same under dynamic conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1996
- Accession Number
- ADA319954
Entities
People
- Louise V. Parker
- Thomas A. Ranney
Organizations
- Cold Regions Research and Engineering Laboratory