The use of differential pulse anodic stripping voltammetry and diffusive gradient in thin films for heavy metals speciation in soil solution

Abstract

Abstract:In the soil solutions obtained in situ with suction cups from soils (Cambisol and Fluvisol) of pot experiment with Salix smithiana Smith, Lolium perenne L. and Thlaspi caerulescens J. & C. Presl heavy metals species (Cd, Pb and Cu) were assayed by differential pulse anodic stripping voltammetry and diffusive gradient in thin films. Prediction of accumulation performed best at free metal ion concentrations in unchanged pH (in 10 -3 mol L -1 NaClO 4 base electrolyte). The speciation provided by differential pulse anodic stripping voltammetry according to pH can provide a detailed description of the soil solution matrix. The concentration of free metals in unchanged pH represents a small part of the total content and varied from 0.04 to 0.75% with two exceptions found for accumulating plants (the content of Cd 2+ in the soil solution from T. caerulescens was about 6% and the content of Cu 2+ in the soil solution from S. smithiana was about 30%). The available concentration as determined by diffusive gradient in thin films was not in correlation with the heavy metals concentration in plant biomass. Warsaw and Springer-Verlag Berlin Heidelberg. © Versita

An electrochemical device generating metal ion adducts of organic compounds for electrospray mass spectrometry

“…A soil solution used as a representative biological matrix was prepared from a forest soil [37], sampled according to the methodology described in [30,38]. The selection of suitable supporting electrolyte (SE) is essential for the proper functionality of the electrochemical device.…”

“…During the measurement, the species of the analyte enter into the device and two processes are expected: (i) the free analyte becomes complexed with the metal cations electrochemically generated from the WE material, otherwise (ii) other forms of the analyte (in adducts with the sample matrix) become decayed due to the competition between the substances forming the species and the metal cations electrochemically generated from the WE material [29]; they form new, more stable adducts: The separation effect rooted from the creation of several adducts (just one adduct in the ideal case) of the analyte with the generated metal cations. In biological samples the analyte is usually present in various adducts with different compounds (species) originating from the sample matrix [30]. A natural state of the investigated analyte is disrupted by its reaction with highly reactive nascent metal [31,32] or by the reaction with electrode material to provide the expectable specie(s) with the metal cation originating from the electrode body [18].…”

Effective Concentration of Elements in Root Zone of Norway Spruce Stand 16 Years After Fertilization Probed with DGT

“…1 h in plastic bags (temperature 4°C) during the transport to the laboratory and then disassembled immediately. Chelex gel discs were leached for 48 h (at 4°C) in 1.5-mL vials containing 1 mL 2 mol L −1 HNO 3 (Jaklová Dytrtová et al 2008). The metal content in digests (diluted three times) was determined by inductively coupled plasma optical emission spectrometry (ICP-OES) (VARIAN VistaPro, Varian, Australia).…”

“…This technique was also tested in model solutions in the presence of low-molecular-weight organic acids (very important ligands for metals in soils, Jones 1998; Jaklová ), in hydroponic systems ), in freshwaters (Unsworth et al 2006), in soil solutions (Jaklová Dytrtová et al 2008), and in soils (e.g., Jaklová Dytrtová et al 2008;Degryse et al 2009). This technique was also applied in forest soil on a site supporting alder plantation (Jakl et al 2014).…”

“…The deployment of DGT in soil may hypothetically provide information about element availability, interpreted as Beffective concentration^ (Ruello et al 2008) or BDGT concentration^in the meaning of Bavailable concentration^(Jaklová Dytrtová et al 2008;Jakl et al 2014), expressed in milligrams per liter. For this purpose, the binding layer Chelex-100 is applicable in the assessment of many elements (Garmo et al 2003) by the DGT approach.…”