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Quantitation of selenium in plants, soils and sludges was achieved by isotope dilution-mass spectrometry using a benchtop instrument. Samples for analysis were spiked with 76 Se isotope solution. Plant material was digested on a heating block at 150°C using a mixture of nitric acid and hydrogen peroxide. Selenium in soils and sludges was released by treatment with nitric acid followed...
Adsorption-desorption equilibria of phenylurea herbicides (chlortoluron, isoproturon, metobromuron, chloroxuron, difenoxuron) were determined in two different soils. Organic carbon content of the soils ranged from 1.1-5.6% and the clay fraction from 25-30%. Spiked aqueous suspensions of soils were centrifuged and urea derivative concentrations in the aqueous phase were determined using a HPLC-UV...
A solid-state nitrate ion-selective electrode based on an Urushi matrix membrane was developed. Urushi, a natural oriental lacquer, has excellent mechanical strength and binding affinity for metal electrodes. Using the same technique for a dip-coating ion-selective electrode, an electrode was prepared by coating and hardening a sensing membrane on the metal base. The effects of the metal electrode...
A fully automated method for leaching of TCP (3,5,6-trichloro-2-pyridinol, the major degradation product of the widely used chlorpyrifos insecticides) from soil and fruit with subsequent determination by ELISA is reported. The automation of the weighing and leaching steps enables unattended development of sample preparation. The determination of the target analyte, traditionally performed by liquid...
A module for continuous high pressure-temperature leaching is proposed. The overall approach involves the coupling of an extractor with a continuous-flow manifold where the analyte forms a complex with SCN - , which is driven to a flow-cell packed with a suitable material for retention and continuous monitoring of this process which in turn is a way for indirect monitoring of the leaching...
The coupling of an enzyme immunoassay with a superheated water extraction is an attractive technique because of the reduced use of hazardous solvents, due to their hostile impact on the environment. This paper describes the use of superheated water extraction and enzyme immunoassay (EIA) for the determination of polycyclic aromatic hydrocarbons (PAHs) in native (not spiked) surface soil and sediment...
The use of dilute acid for mercury extraction from geological samples with microwave assisted heating was investigated. An orthogonal array design OA 16 (4 1 ×2 12 ) was applied to select the optimum conditions. The effects of the concentration of HNO 3 , the additions of HCl and H 2 S0 4 , the extraction time and their interactions were evaluated by...
The efficiency of methods for the determination of hexachlorobenzene (HCB) and pentachlorophenol (PCP) in soil samples was evaluated. An on-line method was applied for HCB determination. Soil samples were transferred to chromatographic columns prepacked with alumina. The HCB elution was processed with n-hexane. The PCP was extracted from soil samples with n-hexane–acetone in an ultrasonic bath. After...
2-Chloroethylethyl sulfide (CEES) is used as a simulant for mustard (HD) in a study to develop secondary ion mass spectrometry (SIMS) for rapid, semi-quantitative detection of mustard on soil. Selectivity and sensitivity are markedly improved employing multiple-stage mass spectrometry (MS n ) using an ion trap SIMS. C 2 H 5 SC 2 H 4+ from CEES eliminates...
Microwave-assisted extraction (MAE) for the separation of atrazine, simazine and prometryne from synthetic soil samples, using water and some organic solvents as the extractants, was studied in detail. The effects of the soil matrix, the soil moisture and the pH of the aqueous extraction system on the MAE efficiency were also studied. It was found that the three triazines could be efficiently extracted...
We have combined affinity purification concepts with novel renewable-surface microcolumns in a sequential injection system for the automated and rapid isolation and purification of nucleic acids directly from crude soil extracts. Geobacter chapellii DNA was spiked at femtomolar concentrations into clean solutions or crude soil extracts containing picomolar concentrations of competitive DNA, humic...
Fulvic acids (FAs) were extracted by alkali extraction from different soil samples in China, then purified using resins and characterized by Fourier transform infrared spectroscopy. The complexing ability of FAs was investigated by measuring the stability constants of rare earth elements (REEs) (La 3+ , Ce 3+ , Sm 3+ , Gd 3+ , Y 3+ )...
Hazardous waste site characterization, forensic investigations, and land mine detection are scenarios where soils may be collected and analyzed for traces of nitroaromatic, nitramine, and nitrate ester explosives. These thermally labile analytes are traditionally determined by high-performance liquid chromatography (HPLC); however, commercially available deactivated injection port liners and wide-bore...
Acidified subcritical water is proposed for the continuous extraction of metals (namely, lead, copper, cadmium, arsenic, selenium and mercury) from soils prior to: (a) continuous derivatisation (by hydride formation for As and Se, and cold vapour formation for Hg) and determination by atomic fluorescence; and (b) determination by Graphite Furnace-Atomic Absorption Spectrometry for Pb, Cu and Cd. Soil...
A method for speciation of vanadium in soil is presented in this work. The sequential extraction analysis procedure of Tessier et al. for heavy metals was used for the vanadium separation. The method consists of sequential leaching of the soil samples to separate five fractions of metals: (1) exchangeable, (2) bound to carbonates, (3) bound to Fe-Mn oxides, (4) bound to organic matter and (5) residual...
Cadmium, copper and lead in soils, sediments and spiked sea water samples have been determined by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman effect background corrector using NH 4 NO 3 , Sc, Pd, Sc + NH 4 NO 3 , Pd + NH 4 NO 3 , Sc + Pd and Sc + Pd + NH 4 NO 3 as chemical modifiers. A comprehensive comparison was...
A new flow injection on-line sequential extraction procedure coupled with hydride generation atomic fluorescence spectrometry (HG-AFS) was developed for rapid and automatic fractionation of arsenic in soils. The developed methodology involved a three-step sequential extraction procedure with deionized water, KOH solution, and HCl solution. 25mg of the soil sample packed into a microcolumn (4mm i.d...
In order to reduce the amount of sample to be collected and the time consumed in the analytical process, a broad range of analytes should be preferably considered in the same analytical procedure. A suitable methodology for pesticide residue analysis in soil samples was developed based on ultrasonic extraction (USE) and gas chromatography–mass spectrometry (GC–MS). For this study, different classes...
Organic phosphorus is an important component of soil biogeochemical cycles, but must be extracted from soil prior to analysis. Here we critically review the extraction of soil organic phosphorus, including procedures for quantification, speciation, and assessment of biological availability. Quantitative extraction conventionally requires strong acids and bases, which inevitably alter chemical structure...
Phosphorus nuclear magnetic resonance ( 31 P-NMR) spectroscopy has advanced our knowledge of organic phosphorus (P) in soils and environmental samples more than any other technique. This paper reviews the use of 31 P-NMR spectroscopy for soil, water and other environmental samples. The requirements for a successful solid-state or solution 31 P-NMR experiment are described,...
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