Speciation of As(III) and As(V) in water samples by graphite furnace atomic absorption spectrometry after solid phase extraction combined with dispersive liquid-liquid microextraction based on the solidification of floating organic drop

Arsenic Speciation of Waters from the Aegean Region, Turkey by Hydride Generation: Atomic Absorption Spectrometry

Arsenic in drinking water is a serious problem for human health. Since the toxicity of arsenic species As(III) and As(V) is different, it is important to determine the concentrations separately. Therefore, it is necessary to develop an accurate and sensitive method for the speciation of arsenic. It was intended with this work to determine the concentrations of arsenic species in water samples collected from Izmir, Manisa and nearby areas. A batch type hydride generation atomic absorption spectrometer was used. As(V) gave no signal under the optimal measurement conditions of As(III). A certified reference drinking water was analyzed by the method and the results showed excellent agreement with the reported values. The procedure was applied to 34 water samples. Eleven tap water, two spring water, 19 artesian well water and two thermal water samples were analyzed under the optimal conditions.

Development of magnetic graphene oxide adsorbent for the removal and preconcentration of As(III) and As(V) species from environmental water samples

New-generation adsorbent, Fe3O4@SiO2/GO, was developed by modification of graphene oxide (GO) with silica-coated (SiO2) magnetic nanoparticles (Fe3O4). The synthesized adsorbent was characterized using Fourier transform infrared spectroscopy, X-ray diffractometry, energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. The developed adsorbent was used for the removal and simultaneous preconcentration of As(III) and As(V) from environmental waters prior to ICP-MS analysis. Fe3O4@SiO2/GO provided high adsorption capacities, i.e., 7.51 and 11.46 mg g(-1) for As(III) and As(V), respectively, at pH 4.0. Adsorption isotherm, kinetic, and thermodynamic were investigated for As(III) and As(V) adsorption. Preconcentration of As(III) and As(V) were studied using magnetic solid-phase extraction (MSPE) method at pH 9.0 as the adsorbent showed selective adsorption for As(III) only in pH range 7-10. MSPE using Fe3O4@SiO2/GO was developed with good linearities (0.05-2.0 ng mL(-1)) and high coefficient of determination (R (2) = 0.9992 and 0.9985) for As(III) and As(V), respectively. The limits of detection (LODs) (3× SD/m, n = 3) obtained were 7.9 pg mL(-1) for As(III) and 28.0 pg mL(-1) for As(V). The LOD obtained is 357-1265× lower than the WHO maximum permissible limit of 10.0 ng mL(-1). The developed MSPE method showed good relative recoveries (72.55-109.71 %) and good RSDs (0.1-4.3 %, n = 3) for spring water, lake, river, and tap water samples. The new-generation adsorbent can be used for the removal and simultaneous preconcentration of As(III) and As(V) from water samples successfully. The adsorbent removal for As(III) is better than As(V).

Preconcentration of Cu(II), Co(II), and Ni(II) using an Optimized Enrichment Procedure: Useful and Alternative Methodology for Flame Atomic Absorption Spectrometry

In this paper, a new solid phase extraction procedure is described for Cu(II), Co(II), and Ni(II). Silica gel which was coated with N,N'-bis(4-methoxysalicylidene) ethylenediamine (MSE) is used as a sorbent. Three independent variables were optimized using central composite design (CCD) for sorption and elution of metal ions. The optimum values of sorption and elution variables allowed simultaneous preconcentration of the ions in same conditions as follows, for sorption, pH 6.9, flow rate 5.4 mL min(-1), sample volume 50.0 mL, and for elution, flow rate 2.6 mL min(-1), eluent concentration 1.0 mol L(-1), eluent volume 5.0 mL. The detection limits (LOD) were found to be 1.1 µg L(-1) for Cu(II), 7.4 µg L(-1) for Co(II), and 7.5 µg L(-1) for Ni(II) and preconcentration factor was 200 for each of the ions. The accuracy of the method was tested with Lake Ontario water and multi-element standard solution. The proposed method was also applied to various water samples. The proposed method can be alternatively suggested as accurate, precise, easy, and a cheap method for Cu(II), Co(II), and Ni(II) determination.

Combination of counter current salting-out homogenous liquid-liquid extraction and dispersive liquid-liquid microextraction as a novel microextraction of drugs in urine samples

The counter current salting-out homogenous liquid-liquid extraction (CCSHLLE) joined with the dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) has been developed as a high preconcentration technique for the determination of different drugs in urine samples. Amphetamines were employed as model compounds to assess the extraction procedure and were determined by high performance liquid chromatography-ultraviolet detection (HPLC-UV). In this method, initially, NaCl as a separation reagent is filled into a small column and a mixture of urine and acetonitrile is passed through the column. By passing the mixture, NaCl is dissolved and the fine droplets of acetonitrile are formed due to salting-out effect. The produced droplets go up through the remained mixture and collect as a separated layer. Then, the collected acetonitrile is removed with a syringe and mixed with 30.0μL 1-undecanol (extraction solvent). In the second step, the 5.00mLK2CO3 solution (2% w/v) is rapidly injected into the above mixture placed in a test tube for further DLLME-SFO. Under the optimum conditions, calibration curves are linear in the range of 1-3000μgL(-1) and limit of detections (LODs) are in the range of 0.5-2μgL(-1). The extraction recoveries and enrichment factors ranged from 78 to 84% and 157 to 168, respectively. Repeatability (intra-day) and reproducibility (inter-day) of method based on seven replicate measurements of 100μgL(-1) of amphetamines were in the range of 3.5-4.5% and 4-5%, respectively. The method was successfully applied for the determination of amphetamines in the actual urine samples. The relative recoveries of urine samples spiked with amphetamine and methamphetamine are 90-108%.

In-syringe low-density ionic liquid dispersive liquid–liquid microextraction for the fast determination of pyrethroid insecticides in environmental water samples by HPLC-DAD

In-syringe low-density ionic liquid dispersive liquid–liquid microextraction.

Speciation analysis of inorganic arsenic in food and water samples by electrothermal atomic absorption spectrometry after magnetic solid phase extraction by a novel MOF-199/modified magnetite nanoparticle composite

A novel magnetic metal–organic framework (MOF-199/dithiocarbamate modified magnetite nanoparticles composite) was synthesized and utilized for speciation analysis of inorganic arsenic.

Arsenic: A Review of the Element's Toxicity, Plant Interactions, and Potential Methods of Remediation

Arsenic is a naturally occurring element with a long history of toxicity. Sites of contamination are found worldwide as a result of both natural processes and anthropogenic activities. The broad scope of arsenic toxicity to humans and its unique interaction with the environment have led to extensive research into its physicochemical properties and toxic behavior in biological systems. The purpose of this review is to compile the results of recent studies concerning the metalloid and consider the chemical and physical properties of arsenic in the broad context of human toxicity and phytoremediation. Areas of focus include arsenic's mechanisms of human toxicity, interaction with plant systems, potential methods of remediation, and protocols for the determination of metals in experimentation. This assessment of the literature indicates that controlling contamination of water sources and plants through effective remediation and management is essential to successfully addressing the problems of arsenic toxicity and contamination.

Trace analysis of some organophosphorus pesticides in rice samples using ultrasound-assisted dispersive liquid-liquid microextraction and high-performance liquid chromatography

An ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of a floating organic drop method followed by high-performance liquid chromatography was developed for the extraction, preconcentration, and determination of trace amounts of organophosphorus pesticides in rice samples. Variables affecting the performance of both steps were thoroughly investigated. Some effective parameters on extraction were studied and optimized. Under the optimum conditions, recoveries for rice sample are in the range of 58.0-66.0%. The calibration graphs are linear in the range of 4-800 μg/kg and, limits of detection and limits of quantification are in the range of 1.5-3 and 4.2-8.5 μg/kg, respectively. The relative standard deviation for 50.0 μg/kg of organophosphorus pesticides in rice sample are in the range of 4.4-5.1% (n = 5). The obtained results show that proposed method is a fast and simple method for the determination of pesticides in cereals.

Low density solvent based dispersive liquid–liquid microextraction followed by vortex-assisted magnetic nanoparticle based solid-phase extraction and surfactant enhanced spectrofluorimetric detection for the determination of aflatoxins in pistachio nuts

A novel extraction method based on DLLME followed by VA-D-SPE was developed to determine total aflatoxins in pistachio.

Efficient and selective extraction and determination of ultra trace amounts of Hg2+ using solid phase extraction combined with ion pair based surfactant-assisted dispersive liquid–liquid microextraction

Solid phase extraction coupled with ion pair based surfactant-assisted dispersive liquid–liquid microextraction based on the solidification of the floating organic drop method was applied for determination of Hg²⁺ in different samples.