Does bottle type and acid-washing influence trace element analyses by ICP-MS on water samples? A test covering 62 elements and four bottle types: high density polyethene (HDPE), polypropene (PP), fluorinated ethene propene copolymer(FEP) and perfluoroalkoxy polymer( PFA)

Groundwater samples from 15 boreholes in crystalline bedrock aquifers in So uth Norway (Oslo area) have been collected in parallel in five different cl ear plastic bottle types thigh density polyethene [HDPE], polypropene [PP, two manufacturers], fluorinated ethene propene copolymer [FEP] and perfluor oalkoxy polymer [PFA]. In the cases of polyethene and polypropene, parallel samples have been collected in factory-new (unwashed) bottles and acid-was hed factory-new bottles. Samples have been analysed by I(:P-MS techniques f or a wide range of inorganic elements down to the ppt (ng/l) range. It was found that acid-washing of factory-new flasks had no clear systematic benef icial effect on analytical result. On the contrary, for the PP-bottles conc entrations of Pb and Sn were clearly elevated in the acid-washed bottles. L ikewise, for the vast majority of elements, bottle type was of no importanc e for analytical result. For six elements (Al, Cr, Hf, Hg, Pb and Sn) some systematic differences for one or more bottle types could be tentatively di scerned, but in no case was the discrepancy of major cause for concern. The most pronounced effect was for Cr, with clearly elevated concentrations re turned from the samples collected in HDPE bottles, regardless of acid-washi ng or not. For the above six elements, FEP or PFA bottles seemed to be marg inally preferable to PP and HDPE. In general, cheap HDPE, factory new, unwa shed flasks are suitable for sampling waters for ICP-MS ultra-trace analysi s of the elements tested. (C) 1999 Elsevier Science B.V. All rights reserve d.