On-line coupling of flow injection sequential extraction to hydride generation atomic fluorescence spectrometry for fractionation of arsenic in soils

Analytical Tools for Monitoring Arsenic in the Environment

“…Flow injection (FI) on-line sequential extraction coupled with a detection scheme provides rapid, automatic, and sensitive fractionation of As in soils. The procedure offers several advantages including better accuracy, less sample/reagent consumption, and lower risk of contamination and analyte loss [71] compared with traditional batch-mode sequential extraction.…”

Fluidized-bed column method for automatic dynamic extraction and determination of trace element bioaccessibility in highly heterogeneous solid wastes

“…Intensive research in the field of dynamic extraction has been over the past few years devoted to the design of low to moderate pressure flow setups capitalized on the different generations of flow analysis, that is, continuous-flow analysis, flow injection analysis and sequential injection analysis, wherein the amount of solid sample usually loaded into the flow-through container ranged from 5 to 300 mg [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] to prevent excessive backpressure in the flow network. In continuous-flow rotating column-based fractionation assays, larger sample masses have been partitioned, yet the particle size distribution should be carefully controlled (samples are frequently sieved down to 250 m) because of the narrow tubing of the column, usually 1.5 mm i.d.…”

“…The minute quantities of solid samples loaded into the flow assemblies have limited the applicability of flow-based dynamic extraction methods to merely homogeneous solids or materials with a certain degree of heterogeneity but with preliminary sample milling or crushing to assure particle size homogenization, which would inevitably lead to the overestimation of the extractable content of target species because inaccessible phases would become exposed to the extractant [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Evaluation of the actual environmental availability of trace elements in highly heterogeneous raw solid wastes, e.g., municipal solid waste incineration (MSWI) bottom ashes exploiting the aforementioned flow setups would thus be inconceivable as the test portion assayed is to be most likely not representative of the bulk medium.…”

A multisyringe flow-through sequential extraction system for on-line monitoring of orthophosphate in soils and sediments

“…Several attempts have been made on the characterization and evaluation of dynamic (non steady-state) partitioning methods, mostly exploiting continuous-flow or flow injection systems, where fresh portions of leaching agents are continuously provided to small containers or columns containing the solid material [7][8][9][10][11][12][13][14][15][16][17][18]. Dynamic approaches should be regarded as appealing avenues for fractionation assays not only because they alleviate the shortcomings of batch procedures including analyte re-adsorption and limited information on the size of actual available pools, but at the same time result also in improved precision and sample throughput.…”