Solidified Floating Organic Drop Microextraction Research Articles

Switchable hydrophilicity solvent-assisted solidified floating organic drop microextraction for separation and determination of arsenic in water and fish samples

The aim of the current study was to separate and determine arsenic in water and fish samples using a novel and green solidified floating organic drop microextraction (SFODME), which is based on switchable hydrophilicity solvent (SHS)-assisted procedure followed by hydride generation atomic absorption spectrometry (HG-AAS). The 4-((2-hydroxyquinoline-7-yl)diazenyl)-N-(4-methylisoxazol-3-yl)benzene sulfonamide (HDNMBA) and tertiary amine (4-(2-aminoethyl)-N,N-dimethylbenzylamine (AADMBA) were used as ligand and SHS, respectively. The use of SHS promotes quantitative extraction of arsenic complexes into an extraction solvent (1-undecanol). Some factors that impact extraction recovery were studied. Under optimal conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.005 μg L−1 and 0.015 μg L−1, respectively. The calibration graph was linear up to 900.0 μg L−1 arsenic, with the enrichment factor is 267. The proposed SHS-SFODME methodology for arsenic quantification in water and fish samples was successfully implemented. The environmental friendliness and safety of proposed method were approved by the Analytical Greenness Calculator (AGREE) and the Blue Applicability Grade Index (BAGI) tools.

Assessment of Non-Steroidal Anti-Inflammatories in River Waters of Northeastern of Brazil: Occurrence and Environmental Risk

The environmental impact of pharmaceuticals is a significant concern, as understanding their presence, spread, and harm in coastal regions remains limited. The occurrence of non-steroidal anti-inflammatory drugs (NSAIDs), namely, mefenamic acid (MFN), diclofenac (DCF) and naproxen (NPX) were studied in river waters. Four sample collections were carried out in five points in the dry and rainy seasons. Solidified floating organic drop microextraction (SFODME) coupled with high performance liquid chromatography using diode array detection (HPLC-DAD) were applied to quantify the presence of MFN, DCF and NPX in river water samples. DCF had the highest concentration (640 ng L-1), followed by NPX (410 ng L-1). MFN was not detected in any point within the used working range (limit of detection (LOD) of 0.07 µg L-1). Additionally, an assessment was conducted to evaluate the environmental risk associated with the pharmaceuticals detected in freshwater, specifically in various organisms including algae, mollusks, amphibians, fish, and cnidarians, spanning different trophic levels. The ecotoxicological assessment showed risks ranging from low to high, indicating deleterious effects on several exposed species. No high environmental risk was detected in the sampling areas. Although no immediate negative effects were detected, the potential impact on non-target species should not be disregarded.

Utilizing deep eutectic solvent for facile, selective and sustainable sequestration of plutonium

In the recent surge of green and cheap energy for future generation; nuclear industry is going to play a pivotal role and reprocessing of nuclear fuel through safe and systematic approach is the key. In that direction recent literature has shown that there is lack of better and improved methods towards efficient extraction of highly radiotoxic and hazardous plutonium from nuclear waste. Herein, we have utilized a greener and cost effective indigenously synthesized deep eutectic solvent (DES) for the selective extraction of plutonium from (Am, Pu, U) waste. The maximum D value achieved for Pu was 67.42 at 5 mol L−1 HNO3 media and the equilibrium uptake capacity was found to be 107.28 ± 5 μg of Pu/g of C12DES. This was followed by solidified floating organic drop micro-extraction (SFODME) technique for its quantification. High radiation stability of this DES (upto 750 kGy) highlighted its great potential in nuclear fuel reprocessing. Several other reprocess parameters were studied and optimized such as DES volume, alkyl chain length attached to hydrogen bond acceptor (HBA), actinide concentration and speciation and its acidity to achieve best extraction of plutonium ion form the waste stream. Regeneration capability and reusability of the DES employing stripping agents gave encouraging results as 95% of Pu could be stripped in a single cycle using 1 M hydroxylamine hydrochloride as the stripping agent. The developed method was applied for recovery and quantification of Pu from real samples, viz. (U,Pu) Carbide fuel solution, radioactive research waste and synthetic dissolver solution. We believe this work is a way forward in resolving a variety of issues that exist in health physics and reprocessing laboratories of nuclear installation pertaining to selective and efficient extraction of Pu (IV).

Solidified floating organic drop microextraction in tandem with syringe membrane miro-solid phase extraction for sequential detection of thallium (III) and thallium (I) by graphite furnace atomic absorption spectrometry

In the present study, a novel method based on solidified floating organic drop microextraction (SFODME) combined with syringe membrane micro-solid phase extraction (SMMSPE) was proposed for the sequential separation and enrichment of Tl(III) and Tl(I) followed by graphite furnace atomic absorption spectrometry detection. In SFODME, Tl(III) can react with 1-(2-Pyridylazo)-2-naphthol at pH 8.0 to form the complexes which can be extracted into an organic drop, while Tl(I) was remained in the solution. In SMMSPE, flexible TiO2@SiO2 nanofiber membrane was used as the sorbent for the enrichment of Tl(I) in the sample solution after the separation of Tl(III). This method did not require tedious pre-oxidation/pre-reduction operation and time-consuming centrifugation/filtration steps, which may cause sample contamination and analysis errors. Main parameters influencing the separation and enrichment of the target species were studied. Under the selected conditions, the detection limits for this method were 1.7 and 2.6 ng/L for Tl(III) and Tl(I) with relative standard deviations of 6.1 % and 5.2 %, respectively. This method was successfully used for the determination of the target species in environmental water samples and two certified reference materials. The determined values were in good agreement with the certified values.

Determination of Mn(II) and Mn(VII) in beverage samples using magnetic dispersive micro-solid phase extraction coupled with solidified floating organic drop microextraction followed by graphite furnace atomic absorption spectrometry

Magnetic dispersive micro-solid phase extraction (MDMSPE) was coupled with solidified floating organic drop microextraction (SFODME) for direct separation and preconcentration of Mn(II) and Mn(VII) before graphite furnace atomic absorption spectrometry determination. MDMSPE involved use of magnetic ZnFe2O4 nanotubes for adsorbing Mn(VII). Sorbent was isolated from aqueous phase by an external magnet. Mn(II) in upper solution from MDMSPE was further enriched by SFODME. This method avoids tedious pre-oxidation/pre-reduction operation and time-consuming centrifugation/filtration step. An enrichment factor of 200-fold was obtained. Detection limits of this method were 0.005 and 0.007 ng mL−1 for Mn(II) and Mn(VII) with relative standard deviations of 4.0% and 4.8% (n = 9), respectively. This method was successfully used for detection of Mn(II) and Mn(VII) in tap water, ice tea, energy drink, mineral water, sprite drink and carbonated drink. A certified reference material of water sample was analyzed with satisfactory results. Recoveries of spike experiments ranged from 92.5 to 106%.

Solidified floating organic drop microextraction (SFODME) for the simultaneous analysis of three non-steroidal anti-inflammatory drugs in aqueous samples by HPLC.

In this work, a liquid-liquid microextraction methodology using solidified floating organic drop (SFODME) was combined with liquid chromatography and UV/Vis detection to determine non-steroidal anti-inflammatory drugs (NSAIDs) naproxen (NPX), diclofenac (DCF), and mefenamic acid (MFN) in tap water, surface water, and seawater samples. Parameters that can influence the efficiency of the process were evaluated, such as the type and volume of the extractor and dispersive solvents, effect of pH, agitation type, and ionic strength. The optimized method showed low detection limits (0.09 to 0.25μgL-1), satisfactory recovery rates (90 to 116%), and enrichment factors in the range between 149 and 199. SFODME showed simplicity, low cost, speed, and high concentration capacity of the analytes under study. Its use in real samples did not demonstrate a matrix effect that would compromise the effectiveness of the method, being possible to apply it successfully in water samples with different characteristics.

Sensitive determination of cadmium using solidified floating organic drop microextraction-slotted quartz tube-flame atomic absorption spectroscopy.

In this study, solidified floating organic drop microextraction (SFODME) by 1-undecanol was combined with slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) for the determination of cadmium at trace levels. Formation of a complex with 4,4'-dimethyl-2,2'-bipyridine facilitated the extraction of cadmium from aqueous solutions. Several chemical variables were optimized in order to obtain high extraction outputs. Parameters such as concentration of the ligand, pH, and amount of buffer solution were optimized to enhance the formation of cadmium complex. The SFODME method was assisted by dispersion of extractor solvent into aqueous solutions using 2-propanol. Under the optimum extraction and instrumental conditions, the limit of detection and limit of quantitation values obtained for cadmium using the combined methods (SFODME-SQT-FAAS) were found to be 0.4 and 1.3μgL-1, respectively. Matrix effects on the method were also examined for tap water and wastewater, and spiked recovery results were found to be very satisfactory. Graphical Abstract SFODME-SQT-FAAS system for sensitive determination of cadmium.

Determination of cadmium in herbs by SFODME with ETAAS detection.

A method for the determination of cadmium in herb samples based on solidified floating organic drop microextraction (SFODME) using 1-(2-Pyridylazo)-2-naphthol (PAN) as a chelating reagent and detection by electrothermal atomic absorption spectrometry (ETAAS) was developed in the present work. The effects of pH, extraction solvent, extraction time, stirring rate, and extraction temperature were investigated. Under the optimized conditions, the calibration graph was linear in the range of 0.017-3.0μgL-1, with a detection limit (LOD) of 0.0052μgL-1. The relative standard deviation (%RSD) for 6 replicate measurements of 1.0μgL-1 cadmium was ±2.67%. The method was applied to the analysis of 10 types of Thai herb samples. Percentage recoveries were in the range 94.5-110.2%. It was found that cadmium concentrations in all Thai herb samples were less than the maximum residue level.

Dual extraction based on solid phase extraction and solidified floating organic drop microextraction for speciation of arsenic and its distribution in tea leaves and tea infusion by electrothermal vaporization ICP-MS

A dual extraction based on solid phase extraction (SPE) and solidified floating organic drop microextraction (SFODME) was developed for As species in tea leaves and tea infusion by electrothermal vaporization inductively coupled plasma mass spectrometry, including total, suspended, soluble, organic and inorganic As as well as As(III) and As(V). In SPE step, titanium dioxide nanotubes were used for preconcentration of analytes and removal of sample matrix. Elution solution from SPE was employed for further preconcentration and separation of analytes with SFODME. Under optimal conditions, detection limits of this method were 0.046 and 0.072pgmL−1 with relative standard deviations of 6.3% and 5.8% for As(III) and As(V) (n=9, c=1.0ngmL−1), respectively. A preconcentration factor of 500-fold was achieved for As(III) and As(V). This method was successfully applied for analysis of speciation of arsenic and its distribution in tea leaves, tea infusion and certified reference material of tea leaves.

Solidified floating organic drop microextraction for speciation of Se (IV) and Se (VI) in water samples prior to electrothermal atomic absorption spectrometric detection

A simple and fast solidified floating organic drop microextraction (SFODME) method is suggested for the speciation of Se (IV) and Se (VI) in water samples prior to electrothermal atomic absorption spectrometric (ETAAS) detection. For that purpose, 1-phenylthiosemicarbazide (PTC) was used as chelating agent and undecanol was used as extraction solvent. The pH of solution, extraction solvent volume, amount of ligand, effect of time for complex formation, and effect of possible foreign ions were also evaluated for quantitative and effective extraction of analyte. Under optimized parameters, detection limit (0.19 $\mu $g L$^{-1})$, limit of quantification (0.60 $\mu $g L$^{-1})$, relative standard deviation (4.6%), linear range (0.60-24 $\mu $g L$^{-1})$, relative error (-4.3%), and enrichment factor (53) were calculated, respectively. The accuracy of the SFODME method was confirmed with analysis of reference material (LGC 6010 Hard drinking water). The presented method was applied to water samples.

Solidified floating organic drop microextraction combined with high performance liquid chromatography for the determination of carbamazepine in human plasma and urine samples.

Solidified floating organic drop microextraction (SFODME) in combination with high performance liquid chromatography was used for separation/preconcentration and determination of carbamazepine (CBZ) in human plasma and urine samples. Parameters that affect the extraction efficiency such as the type and volume of extraction solvent, ionic strength, sodium hydroxide concentration, stirring rate, sample volume and extraction time, were investigated and optimized. Under the optimum conditions (extraction solvent, 40 µL of 1-undecanol; sodium hydroxide concentration, 1 mol/L; temperature, 50 °C; stirring speed, 400 r/min; sample volume, 8 mL; sodium chloride concentration, 3% (w/v) and extraction time, 60 min) the calibration curve was found to be linear in the mass concentration range of 0.4-700.0 µg/L. The limit of detection (LOD) was 0. 1 µg/L and the relative standard deviation (RSD) for six replicate extraction and determination of carbamazepine at 100 µg/L level was found to be 4.1%. The method was successfully applied to the determination of CBZ in human plasma and urine samples.

Simultaneous spectrophotometric determination of Fe(III) and Al(III) using orthogonal signal correction–partial least squares calibration method after solidified floating organic drop microextraction

A solidified floating organic drop microextraction (SFODME) procedure was developed for the simultaneous extraction and preconcentration of Fe(III) and Al(III) from water samples. The method was based on the formation of cationic complexes between Fe(III) and Al(III) and 3,5,7,2′,4′-pentahydroxyflavone (morin) which were extracted into 1-undecanol as ion pairs with perchlorate ions. The absorbance of the extracted complexes was then measured in the wavelength range of 300–450nm. Finally, the concentration of each metal ion was determined by the use of the orthogonal signal correction–partial least squares (OSC–PLS) calibration method. Several experimental parameters that may be affected on the extraction process such as the type and volume of extraction solvent, pH of the aqueous solution, morin and perchlorate concentration and extraction time were optimized. Under the optimum conditions, Fe(III) and Al(III) were determined in the ranges of 0.83–27.00μgL−1 (R2=0.9985) and 1.00–32.00μgL−1 (R2=0.9979) of Fe(III) and Al(III), respectively. The relative standard deviations (n=6) at 12.80μgL−1 of Fe(III) and 17.00μgL−1 of Al(III) were 3.2% and 3.5%, respectively. An enhancement factors of 102 and 96 were obtained for Fe(III) and Al(III) ions, respectively. The procedure was successfully applied to determination of iron and aluminum in steam and water samples of thermal power plant; and the accuracy was assessed through the recovery experiments and independent analysis by electrothermal atomic absorption spectroscopy (ETAAS).

A novel solidified floating organic drop microextraction method for preconcentration and determination of copper ions by flow injection flame atomic absorption spectrometry in water samples

A simple, rapid and inexpensive solidified floating organic drop microextraction (SFODME) and flow injection flame atomic absorption spectrometric determination (FI-FAAS) method for copper was developed. 3-amino-7-dimethylamino-2-methylphenazine (Neutral red, NR) was used as the complexing agent. Several factors affecting the microextraction efficiency, such as, pH, NR and sodium dodecylbenzenesulfonate (SDBS) concentration, extraction time, stirring rate, and temperature were investigated and optimized. Under optimized experimental conditions an enrichment factor of 541 was obtained for 100 mL of sample solution. The calibration graph was linear in the range of 0.5 - 20.0 ng mL -1 and the limit of detection (3s) was 0.18 ng mL -1 , the limit of quantification (10s) was 0.58 ng mL -1 . The relative standard deviation (RSD) for 10 replicate measurements of 10 ng mL -1 copper was 2.7%. The developed method was successfully applied to the extraction and determination of copper in different certified reference materials (Estuarine water, Slew 3 and fortified water, TM 23.2) and real water samples and satisfactory results were obtained.

Solidified floating organic drop microextraction combined with ETV-ICP-MS for the determination of trace heavy metals in environmental water samples

A new method of solidified floating organic drop microextraction (SFODME) combined with electrothermal vaporization (ETV)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace heavy metals in environmental water samples with sodium diethyldithiocarbamate (DDTC) as both chelating reagent in SFODME and chemical modifier in ETV. The factors affecting the microextraction efficiency were studied in detail and the optimal extraction conditions were established. Under the optimal conditions, the limits of detection (LODs) for SFODME-ETV-ICP-MS determination of Co, Pd, Cd, Hg, Pb and Bi were found to be 0.0060, 0.0091, 0.0020, 0.0041, 0.0170 and 0.0041ngmL−1, respectively, with the relative standard deviations (RSDs) of 2.8–10.0% (c=0.5ngmL−1, n=7). The developed method was successfully applied to the analysis of six target metals in Yangtze River and East Lake water samples with recoveries ranging from 77.7 to 119.1%. To validate the accuracy of the method, a certified reference material of Environmental Water (GSBZ50009-88) was analyzed and the determined values were in good agreement with the certified values.

Determination of ultratrace amounts of dichloro-nitrobenzene and dichloro-nitroaniline in water samples using solidified floating organic drop microextraction (SFODME) and gas chromatography

Solidified floating organic drop microextraction (SFODME) in combination with gas chromatography with an electron capture detector was used for separation/enrichment and determination of 2,5-dichloro-nitrobenzene, 2,3-dichloro-nitrobenzene, and 2,6-dichloro-4-nitroaniline in water samples. The main parameters affecting the performance of SFOME, such as solvent volume, extraction time, stirring rate, extraction temperature, sample volume, nature of the solvent and ionic strength were optimized. Under the optimum experimental conditions, good relative standard deviations of 7.5%, 6.9%, and 9.3% for 7 extractions and determination of 50 ng L^{-1} of 2,5-dichloro-nitrobenzene, 2,3-dichloro-nitrobenzene and 2,6-dichloro-4-nitroaniline were obtained, respectively. Enrichment factors of 1390, 1398, and 1362 and detection limits of 1.4, 1.2, and 10 ng L^{-1} for 2,5-dichloro-nitrobenzene, 2,3-dichloro-nitrobenzene, and 2,6-dichloro-4-nitroaniline were found, respectively.

Determination of copper traces in water samples by flow injection-flame atomic absorption spectrometry using a novel solidified floating organic drop microextraction method

A simple, rapid and inexpensive solidified floating organic drop microextraction (SFODME) and flow injection flame atomic absorption spectrometric determination (FI-FAAS) method for copper were developed. 3-amino-7-dimethylamino-2-methylphenazine (Neutral red, NR) was used as the complexing agent. Several factors affecting the microextraction efficiency, such as, pH, NR and sodium dodecylbenzenesulfonate (SDBS) concentration, extraction time, stirring rate, and temperature were investigated and optimized. Under optimized experimental conditions an enrichment factor of 541 was obtained for 100 mL of sample solution. The calibration graph was linear in the range of 0.5–20.0 ng mL − 1 and the limit of detection (3 s) was 0.18 ng mL − 1 , the limit of quantification (10 s) was 0.58 ng mL − 1 . The relative standard deviation (RSD) for 10 replicate measurements of 10 ng mL − 1 copper was 2.7%. The developed method was successfully applied to the extraction and determination of copper in different certified reference materials (Estuarine water, Slew 3 and fortified water, TM 23.2) and real water samples and satisfactory results were obtained.

Solid-Phase Extraction Clean-up Combined with Solidified Floating Organic Drop Microextraction for the Determination of Trace Manganese(II) in Different Environmental Matrices

Solid-phase extraction (SPE) clean-up combined with solidified floating organic drop microextraction (SFODME) has been developed as a new approach for the extraction and determination of trace manganese(II) in environmental water and vegetable samples. After purification of the samples by a graphene-packed SPE cartridge, SFODME technique was performed on the obtained solution. The main parameters affecting the performance of SFODME, such as type of extraction solvent as well as extraction volume, time, temperature, pH, the amount of the chelating agent, and salt effect were investigated and optimized. Under optimum conditions, a preconcentration factor of 81.0 was obtained from 7.0 mL of sample solution. The calibration graph was linear in the range from 1.90 to 400 μg/L with a detection limit of 0.57 μg/L. The relative standard deviation for ten replicate measurements of 10 and 300 μg/L of manganese(II) were 3.57 and 2.63 %, respectively. The proposed method was applied to tap, sea, river, and vegetable samples, and its accuracy was assessed through the analysis of certified reference water and recovery experiments.

Solidified floating organic drop microextraction and spectrophotometric determination of vanadium in water samples

Solidified floating organic drop microextraction (SFODME) was used as a sample preparation method prior to spectrophotometric determination of trace amounts of vanadium in water samples. 8-Hydroxyquinoline (oxine) was used as the chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of oxine, extraction time, sample and organic phase volume, extraction temperature, and the nature of the organic solvent, were optimized. Under the optimized conditions, an enhancement factor of 38, detection limit of 0.97 \mu g L^{-1}, and good relative standard deviation of \pm 3.9% at 10 \mu g L^{-1} were obtained. The method was successfully applied to the determination of vanadium in tap water, well water, river water, and sea water. The accuracy of the method was assessed through a recovery experiment and independent analysis by graphite furnace atomic absorption spectrometry.

Speciation and determination of ultra trace amounts of chromium by solidified floating organic drop microextraction (SFODME) and graphite furnace atomic absorption spectrometry

Solidified floating organic drop microextraction (SFODME) method in combination with graphite furnace atomic absorption spectrometry (GFAAS) has been used for the determination of chromium species in water and urine samples. 1-undecanol containing 2-thenoyltrifluoroacetone (TTA) was used as a selective chelating agent for the extraction of Cr(III). The total Cr was determined after the reduction of Cr(VI) to Cr(III) with hydroxylamine. The concentration of Cr(VI) was determined from the difference between the concentration of total chromium and the Cr(III). Several variables such as the sample pH, concentration of TTA, salt concentration, extraction time and the sample volume were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.006μgl−1 for Cr(III) and the relative standard deviation for six replicate determinations at 0.1μgl−1 Cr(III) was 5.1%. The proposed method was successfully applied for the determination of chromium species in tap water, well water, mineral water, and urine samples.

A novel solidified floating organic drop microextraction method for preconcentration and determination of copper ions by flow injection flame atomic absorption spectrometry

A rapid, simple and cost effective solidified floating organic drop microextraction (SFODME) and flow injection flame atomic absorption spectrometric determination (FI-FAAS) method for copper was developed. In this method, a free microdrop of 1-undecanol containing 1,5-diphenyl carbazide (DPC) as the complexing agent was transferred to the surface of an aqueous sample including Cu(II) ions, while being agitated by a stirring bar in the bulk of the solution. Under the proper stirring conditions, the suspended microdrop can remain at the top-center position of the aqueous sample. After the completion of the extraction, the sample vial was cooled by placing it in a refrigerator for 10 min. The solidified microdrop was then transferred into a conical vial, where it melted immediately and diluted to 300 μL with ethanol. Finally, copper ions in 200 μL of diluted solution were determined by FI-FAAS. Several factors affecting the microextraction efficiency, such as type of extraction solvent, pH, complexing agent concentration, extraction time, stirring rate, sample volume and temperature were investigated and optimized. Under optimized conditions for 100 mL of solution, the preconcentration factor was 333 and the enrichment factor was 324. The limit of detection (3 s) was 0.4 ng mL −1, the limit of quantification (10 s) was 1.1 ng mL −1 and the relative standard deviation (RSD) for 10 replicate measurements of 10 ng mL −1 copper was 0.9%. The proposed method was successfully applied to the determination of copper in different water samples.