Utilization of Modified Corn Silk as a Biosorbent for Solid-phase Extraction of Cr(III) and Chromium Speciation

Biological substrates: Green alternatives in trace elemental preconcentration and speciation analysis

“…Although a poor dynamic sorption capacity was reached (2.2 mg g −1 ), the authors suggested that the chemical modification of the biosorbent is a simple and feasible process. Chemical modification has also been applied in corn silk for solid SPE of Cr(III) and Cr speciation [103]. An aliquot of 30 mL of sample, at pH 6, was loaded into a minicolumn filled with the biosorbent.…”

Biological cells in the speciation analysis of heavy metals

“…HNO 3 pretreated corn silk showed a similar discrimination adsorption behavior for Cr(III) over Cr(VI) at pH 3-6, facilitating an online chromium speciation approach with a LOD of 0.85 mg L À1 with detection by FAAS. 45 It is generally necessary to immobilize the biological cells onto a solid support in order to facilitate column packing and on-line solid phase extraction operation; most natural biological materials, however, can be directly meshed into particles of suitable size and packed into a micro-column, making it more convenient than the cell-based sorbents. The egg-shell membrane (ESM) was ground, sieved and packed into a microcolumn which was intergraded into a sequential injection ow system, 46 wherein Cr(VI) was selectively adsorbed and spontaneously reduced to Cr(III) under acidic conditions, while the quantitative retention of Cr(III) only occurs at a higher pH value.…”

Improvement of Chromium(VI) Extraction from Acidic Solutions Using a Poly(vinyl chloride)-based Polymer Inclusion Membrane with Aliquat 336 as the Carrier

“…2 Therefore Cr(VI) is often removed from aqueous solutions using anion-exchange techniques, [3][4][5][6] although Cr(VI) can also be removed as Cr(III) after reduction using an appropriate reducing agent. 7,8 In recent years, polymer inclusion membranes (PIMs) have received considerable attention as useful tools for extracting various chemical species from their aqueous solutions. 9,10 A PIM generally consists of a base-polymer, such as poly(vinyl chloride) (PVC), and a carrier, which serves as the extractant.…”