Are You Using the Right Tubing for Well Sampling?
Silicon, teflon, teflon-lined, polyethylene, polypropylene, poly (vinyl chloride), etc., etc., etc. What’s the difference? The type of tubing you use for groundwater sampling has an impact on the accuracy of your sample data. When sampling for volatile organic compounds, for example, the use of specific types of tubing is discouraged.
Some time ago, some scientific-ey, tube-lovin’ folks tested 20 different types of polymeric tubing in organic solutes. The test solutions were monitored for sorption and for signs of leaching from the tubing. Results indicated that rigid fluoropolymers appeared to be best for sampling groundwater because they were least sorptive and did not leach any detectable constituents. The tubings with the poorest performance were polyurethane and flexible PVC.
So what does this mean? Basically, this: If you are sampling for organics, it’s best to spend the extra money on teflon or teflon-lined tubing - Teflon Trumps! If you are sampling for inorganics only, other tubings, like polyethylene, are just fine.