Trace metal contaminants in sediments and soils: comparison between ICP and XRF quantitative determination

A mineralization method HCl-free for heavy metals analysis in sediments and soils by DRC-ICP-MS was developed. The procedure, which uses concentrated nitric, hydrofluoric acid and hydrogen peroxide, was applied for the analysis of arsenic, cadmium, chromium, nickel and vanadium. The same samples were then analyzed, as pressed pellets, by wavelength dispersive X ray fluorescence (WD-XRF) using the dedicated PANalytical Pro Trace solution for the determination of trace elements. Comparison of ICP and XRF data showed good agreement for the elements under investigation, unless for chromium in soils, which recovery was not complete

Trace metal contaminants in sediments and soils: comparison between ICP and XRF quantitative determination

A mineralization method HCl-free for heavy metals analysis in sediments and soils by DRC-ICP-MS was developed. The procedure, which uses concentrated nitric, hydrofluoric acid and hydrogen peroxide, was applied for the analysis of arsenic, cadmium, chromium, nickel and vanadium. The same samples were then analyzed, as pressed pellets, by wavelength dispersive X ray fluorescence (WD-XRF) using the dedicated PANalytical Pro Trace solution for the determination of trace elements. Comparison of ICP and XRF data showed good agreement for the elements under investigation, unless for chromium in soils, which recovery was not complete

Performance of passive sampling with low-density polyethylene membranes for the estimation of freely dissolved DDx concentrations in lake environments

Laboratory and field studies were used to evaluate the performance of low-density polyethylene (PE) passive samplers for assessing the freely dissolved concentrations of DDT and its degradates (DDD and DDE, together referred to as DDx) in an Italian lake environment. We tested commercially available 25 μm thick PE sheets as well as specially synthesized, 10 μm thick PE films which equilibrated with their surroundings more quickly. We measured PE-water partitioning coefficients (Kpew) of the 10 μm thick PE films, finding good correspondence with previously reported values for thicker PE. Use of the 10 μm PE for ex situ sampling of a lake sediment containing DDx in laboratory tumbling experiments showed repeatability of ±15% (= standard deviation/mean). Next, we deployed replicate 10 μm and 25 μm PE samplers (N = 4 for 10 d and for 30 d) in the water and sediment of a lake located in northern Italy; the results showed dissolved DDx concentrations in the picogram/L range in porewater and the bottom water. Values deduced from 10 μm thick PE films compared well (95% of all comparison pairs matched within a factor of 5) with those obtained using PE films of 25 μm thickness when dissolved DDx concentrations were estimated using performance reference compound (PRC) corrections, whether left at the bed-water interface for 10 or 30 days. These results demonstrated the potential of this sampling method to provide estimation of the truly dissolved DDx concentrations, and thereby the mobile and bio-available fractions in both surface waters and sediment beds