Evaluation of metal ion absorptive characteristics of three types of plastic sample bags used for precipitation sampling

Abstract
Simulated precipitation samples containing 16 metal ions were prepared at 4 pH values. Absorptive characteristics of polypropylene, polyethylene and polyester/polyolefin sacks were evaluated at pH 3.5, 4.0, 4.5 and 5.0. Simulated precipitation was in contact with the sacks for 17 days, and subsamples were removed for chemical analysis at 3, 7, 10, 14 and 17 days after initial contact. All 3 types of plastic sacks absorbed Fe throughout the entire pH range. Polypropylene and polyethylene absorbed Pb throughout the entire pH range; polyester/polyolefin sacks absorbed Pb at .gtoreq. pH 4.0. All plastic sacks also absorbed Cu, Mo and V at pH 4.5 and 5.0. Leaching the plastic sacks with 0.7% HNO3 did not result in 100% recovery of Cu, Fe, Pb and V. These sacks would be suitable collection vessels for Ba, Be, Ca, Cd, Co, Li, Mg, Mn, Na, Sr and Zn in precipitation through the pH range of 3.5-5.0.