Sample Pretreatment for Trace Speciation Analysis

On-site separation of arsenic species using a sorbent C18 column modified with APDC followed by ICP-MS determination

“…To ensure the simplicity of the procedure and to minimize the changes of any physical parameters (like temperature or oxygenation), it was proposed to collect small sample volumes for the analysis. 23 The usage of ICP-MS as a determination method allows performing the analysis with only 1 mL of the solution at As levels below 0.5 ng mL −1 in a natural matrix. During the optimization process samples containing 200 ng of arsenates( iii ) in 1.0, 2.0, 3.0, 4.0 and 5.0 mL volumes were introduced into the C18 column with PDC.…”

“…22 Natural water samples require the separation of suspended matter from the dissolved fraction. 23 Lowering the temperature is suggested before separating the suspended particle matter (SPM) from the dissolved phase, but only if the filtration process cannot be performed at the sampling site. Some authors argue that samples containing various forms of As should be stored at low temperature, while others postulate that low temperature may change speciation and recommend storage at room temperature.…”

Effect of Temperature on the Removal of Interferences in the Voltammetric Procedure for the Determination of Cr(VI)

“…Amberlite XAD-7 resin is a polymeric sorbent derived from acrylic esters, which can sorb hydrophobic compounds from water as well as hydrophilic compounds from organic solvents and is used to purify water from organic pollutants (dyes, pesticides, and detergents) [17]. Therefore, It is not surprising that this method of reducing interference related to the presence of surfactants has been used in the voltammetric analysis of many elements [18][19][20][21][22]. The main difficulty is to select appropriate conditions, mainly the composition and pH of the basic electrolyte, to ensure the highest possible efficiency in the adsorption of surface-active substances on the resin and at the same time prevent the adsorption of metal ions on the resin in such conditions.…”

On site separation of inorganic forms of thallium and arsenic in sea water systems followed by ICP-MS determination

“…If the kinetics of reaction between the analyte and the fixer is not fast enough in relation to speciation changes, then one form could still be transformed into the other one. 10…”

“…If the kinetics of reaction between the analyte and the xer is not fast enough in relation to speciation changes, then one form could still be transformed into the other one. 10 Therefore, separating the forms that could change or transform into one another already at the sampling site is much more favorable. Separation of inorganic As species can be performed with solid phase extraction (SPE) cartridges lled with strong anion exchange (SAX) resins.…”