Vortex-assisted Liquid-phase Microextraction Research Articles

Sustainable vortex assisted liquid phase microextraction based on fatty acid switchable solvent for selective and accurate analysis of manganese in food samples

Sustainable vortex assisted liquid phase microextraction based on fatty acid switchable solvent for selective and accurate analysis of manganese in food samples

Deep eutectic solvent-based ferrofluid for highly efficient preconcentration and determination of metronidazole by vortex-assisted liquid-phase microextraction under experimental design optimization

To determine metronidazole in water samples, we developed an environmentally friendly, efficient, and straightforward ferrofluid-based liquid-liquid microextraction sample pretreatment technique. It is coupled with a high-performance liquid chromatography-ultraviolet analytical technique known for its sensitivity, speed, and precision. The magnetic separation of metronidazole-containing ferrofluid from the matrix was effortlessly achieved through the application of an external magnetic field, eliminating the need for centrifugation. Response surface optimization was employed to systematically determine the key experimental parameters influencing extraction efficiency, including pH, NaCl concentration, ferrofluid volume, and vortex duration. With a low detection limit (0.116 ng mL−1), a broad linear range between 0.5 and 700 ng mL−1 was achieved at optimal conditions. Additionally, acceptable spiking recoveries (94.3–97.3 %) and RSD values (≤3.7 %) for intra- and inter-day precision were attained in water samples. In conclusion, the effectiveness of the vortex and ferrofluid combination, along with the convenience of collection and elimination of the need for centrifugation, bestows a highly valuable technique for determining metronidazole in water samples.

Ion-pair vortex assisted liquid phase micro-extraction coupled with UV-visible spectrophotometry for the determination of mesalazine in pharmaceutical formulations

This study demonstrates an effective, simple, and selective method for monitoring mesalazine in pharmaceutical formulations using liquid phase micro-extraction (LPME) and spectrophotometry. Combining LPME with spectrophotometry is an efficient method for analysing various compounds in different matrices. This method is based on extracting the ion-pair formed between the blue indophenol produced by the oxidative reaction of mesalazine and syringic acid in an alkaline medium and a quaternary ammonium salt into a micro-volume of organic solvent. The experimental parameters influencing LPME performance, such as the type and concentration of the quaternary ammonium ion salt and the type and volume of the extractant solvent, were optimised for optimal detection. The linear range and the limit of detection for measuring red species in pharmaceutical formulations were determined to be 0.005-0.080μg/mL-1 and 0.003μg/mL-1, respectively, with a relative standard deviation of 4-6%. The method had a preconcentration factor of 50 at 520nm, making it highly efficient and reliable for monitoring mesalazine in pharmaceutical formulations.

Magnetic nanofluid based on hydrophobic deep eutectic solvent for efficient and rapid enrichment and subsequent determination of cinnamic acid in juice samples: Vortex-assisted liquid-phase microextraction

A quick, environmentally friendly and easy approach for the determination of cinnamic acid in juice samples based on the creation and usage of a novel magnetic nanofluid (mixture of hydrophobic deep eutectic solvent and magnetic nanoparticles) has been reported. Response surface methodology was applied to justify the contribution of the efficient factors including pH, nanofluid volume, ionic strength and vortex time. Cinnamic acid concentrations were monitored and quantified based on their HPLC peak representing linear correlations under the best operational circumstances showing linearity between 3 and 550 ng mL−1. The LOD, LOQ, and enrichment factor for cinnamic acid were 0.8 ng mL−1, 2.7 ng mL−1 and 57.2, respectively. The proposed method was used for enrichment and subsequent determination of cinnamic acid from juice samples which suggests a potential alternative approach for cinnamic acid analysis in complicated food samples.

Assessment of arsenic in water, rice and honey samples using new and green vortex-assisted liquid phase microextraction procedure based on deep eutectic solvent: Multivariate study

The aim of present study was to determine the arsenic in water, honey and rice samples using a new and green vortex-assisted liquid phase microextraction (VA-LPME), which is based on deep eutectic solvent (DES) by hydride generation-atomic absorption spectrometry. Ethylenediamine-N,N'-disuccinic acid (EDDS) was used as chelating reagent for As(III) ions. Four different DES was prepared by using different combination and molar ratios of hydrogen bond donor (HBD) as benzyltriphenylphosphonium chloride, tetra-n-butylammonium bromide, choline chloride and hydrogen bond acceptor (HBA) groups as ethylene glycol, glycerol and diethanolamine. Different parameters such as pH, chelating agent amount, DES types, molar ratio and its volume, emulsifier agents and its volume, vortex time and sample volume were optimized. The accuracy of the method was confirmed with certified reference materials. The DES-VA-LPME method was validated by using linearity r2 0.9985, working range 20–600 ng L−1, limit of detection 6.5 ng L−1, limit of quantitation 20 ng L−1 and enhancement factor 70. Intra and inter day relative standard deviation was found in the range of 3.6 and 4.1% and 4.2 and 4.9%, respectively. The developed procedure was successfully utilized for determination of arsenic in water, honey and rice samples. The factorial design was used to investigate the individual and combined effects of variables as well significant and insignificant effects.

Novel hydrophobic deep eutectic solvent for vortex-assisted liquid phase microextraction of common acaricides in fruit juice followed by HPLC-UV determination.

In the present research, several novel and natural hydrophobic deep eutectic solvents (DESs) were prepared using methyltrioctylammonium chloride (MTOAC) as the hydrogen bond acceptor (HBA) and different types of straight chain alcohols as hydrogen bond donors (HBDs). One of the DESs composed of MTOAC and n-butanol was advantageously used to develop a vortex-assisted liquid phase microextraction (VALPME) method combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) for the determination of common acaricides in fruit juice samples. Several important parameters influencing extraction efficiency were investigated and optimized, including the type and volume of DES, sample solution pH, effect of salt addition and, extraction and vortex time. Under optimal experimental conditions, the method showed good linearity with the correlation coefficients (R2) of 0.9986–0.9991 in the linear range of 2–300 μg L−1, low limits of detection of 0.5–1 μg L−1 and acceptable extraction recoveries in the range of 85–93%. The proposed method was successfully applied for the extraction and preconcentration of trace acaricides in real fruit juice samples, and the results demonstrated the potential of the synthesized DESs for the extraction and determination of contaminants in aqueous samples.

Deep eutectic-based vortex-assisted/ultrasound-assisted liquid-phase microextractions of chromium species

In the present work, vortex-assisted liquid-phase microextraction (VA-LPME) and ultrasound-assisted liquid-phase microextraction (UA-LPME) techniques were used for the speciation of chromium (Cr3+/Cr6+) followed by their determination using flame atomic absorption spectrometry. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as a chelating agent to form a hydrophobic complex with Cr3+; then, it was extracted by choline chloride–phenol mixture, as an extraction solvent. A solution of 1.0 mol L−1 ascorbic acid was used as a reducing agent to convert Cr6+ to Cr3+ (total chromium), and the concentration of Cr6+ was determined from the subtraction of Cr3+ form total chromium. The efficiency of two microextraction techniques was compared in terms of type and amount of extraction solvent, type and volume of extraction solvent, pH of solution, volume of tetrahydrofuran (THF), and extraction time. Based on the obtained results, the extraction recoveries of VA-LPME and UA-LPME techniques are 52% and 60%, respectively. Therefore, UA-LPME is superior technique than VA-LPME. By optimizing different parameters affecting the recovery percentage (RP) of Cr3+, the calibration curve was depicted in the concentration range of 1.5–375.0 ng mL−1 Cr3+ with a correlation coefficient of 0.9937. The limit of detection was 0.4 ng mL−1, and the relative standard deviation (RSD%) for seven replicate analyses of 50.0 µg L−1 of Cr3+ was 3.6%. Finally, the UA-LPME method was successfully applied for the determination of Cr species in different food and water samples.

Assessment of toxic metal ions in tea samples using new microextraction technique based on the solidified deep eutectic solvent followed by GFAAS

In this research, an environmental friendly extraction method based on vortex-assisted liquid-phase microextraction and the solidified deep eutectic solvent (VALPME-SDES) has been developed for the determination of Pb, Cd, Cu, As, and Hg in tea prior to their analysis by graphite furnace atomic absorption spectrometry (GFAAS). A new deep eutectic solvent consisting of 1-decyl-3-methylimidazolium chloride and n-butanoic acid was used as an extraction solvent, yielding the advantages of material stability, low density, and a suitable freezing point near room temperature. The accuracy of the proposed procedure was also assessed by determining the concentration of the studied metal ions in a certified reference material for Green Tea (GBW 10052).

Application of hydrophobic deep eutectic solvent as the carrier for ferrofluid: A novel strategy for pre-concentration and determination of mefenamic acid in human urine samples by high performance liquid chromatography under experimental design optimization

In this study, ferrofluid of magnetic nanoparticles, oleic acid (OA), combined with hydrophobic deep eutectic solvent (Fe3O4 [iron oxide]-OA-DES) was prepared and coupled with vortex-assisted liquid phase microextraction, to pre-concentrate and determine mefenamic acid (MFA) in urine samples, following high performance liquid chromatography (HPLC). With regard to Fe3O4 nanoparticles, all sorbents were identified by SEM, TEM, and XRD. In addition, the influence of different parameters such as pH, ferrofluid volume, ionic strong (NaCl concentration %), and vortex time was investigated and optimized by response surface methodology (RSM) and central composite design (CCD). Maximum MFA extraction predicted by RSM (97.66) was achieved at pH 4.0, 60 μL of ferrofluid, 3%w/v NaCl, and 7 min vortex time with desirability of 1.0. Under the optimized conditions, the limits of detection (LOD) and the limit of quantification (LOQ) were 1.351 ng mL−1 and 4.575 ng mL−1, respectively. The intra-day and inter-day precision (RSD [relative standard deviation]%) in the concentrations of 50, 300, and 700 ng mL−1 of MFA were less than 3.6% and 4.2%, respectively. The method developed in our study could successfully determine MFA in urine samples. The MFA microextraction in urine samples were between 80.25 and 97.44% with RSD% less than 4.60%. Inclusion of ferrofluid in a miniaturized method for sample preparation is proportional to the achievement of high microextraction percentage using green analytical method.

Forced vortex assisted liquid phase microextraction for preconcentration and spectrophotometric determination of mefenamic acid in biological samples

Abstract A new microextraction approach termed forced vortex assisted liquid phase microextraction (FVA-LPME) has been developed and optimized for spectrophotometric determination of mefenamic acid (MFA) as a model compound. FVA-LPME is based on the formation of a rotational vortex of organic phase within aqueous phase and subsequent partition of target analyte between two phases. Rotation of fine layer of organic phase as a solid body within aqueous phase accelerates the mass transfer and improves the extraction efficiency. MFA is extracted into organic phase by FVA-LPME procedure and subsequently derivatized by iodine to form a charge transfer complex for spectrophotometric detection. A response surface methodology (RSM) based on central composite chemometrics design was used for multivariate optimization of the effects of three different parameters influencing the extraction efficiency. Under the optimal conditions, the calibration curve was linear in the range of 10–900 ng mL −1 of MFA with a R 2 of 0.998. The repeatability and reproducibility (RSD%) for 200 ng mL −1 MFA were 2.6% and 3.3%, respectively and limit of detection limit (S/N = 3) was estimated to be 3.1 ng mL −1 . The results demonstrated that the developed method is an accurate, inexpensive, rapid and reliable sample pretreatment method that gives very good enrichment factor and detection limit for extracting and determining MFA in biological samples.

Vortex-assisted surfactant-enhanced emulsification microextraction based on solidification of floating organic drop followed by electrothermal atomic absorption spectrometry for speciation of antimony (ΙΙΙ, V).

Vortex-assisted surfactant-enhanced emulsification microextraction based on solidification of floating organic drop (VASEME-SFO) was used for preconcentration and speciation of antimony (ΙΙΙ, V) followed by electrothermal atomic absorption spectrometry (ETAAS). In this procedure, Triton X-114 was used as emulsifier and 1-undecanol was used as extraction solvent. This method is based on the complexation of Sb(ΙΙΙ) with dithizone (as complexing agent) at pH 2 and extraction of the resulting hydrophobic complex into the extraction solvent (1-undecanol) with vortex-assisted liquid phase microextraction, whereas Sb(V) remained in solution. Sb(ΙΙΙ) in extraction solvent was directly analyzed by ETAAS after dilution with ethanol, and Sb(V) was calculated by subtracting Sb(ΙΙΙ) from the total antimony after reducing Sb(V) to Sb(ΙΙΙ) by L-cysteine. Under the optimized condition, the calibration curve was linear in the range of 0.4-8μgL(-1) of Sb(ΙΙΙ) with a correlation coefficient of 0.9995. The detection limit based on three times of the standard deviation of the blank (n = 8) was 0.09μgL(-1). The validation and the recovery of the proposed method were performed by the analysis of a certified reference material and spike method. The obtained results were in very good agreements with certified values. The proposed method was successfully applied for the determination of antimony species at trace levels in different water samples.

Determination of phenols in environmental water samples by two-step liquid-phase microextraction coupled with high performance liquid chromatography

In this work, a two-step liquid-phase microextraction (LPME) method was presented for the extraction of phenols in environmental water samples. Firstly, the polar phenol in water samples (donor phase) was transferred to 1-octanol (extraction mesophase) by magnetic stirring-assisted LPME. Subsequently, target analytes in the 1-octanol was back extracted into 0.1mol/L sodium hydroxide solution (acceptor phase) by vortex-assisted LPME. By combination of the two-step LPME, the enrichment factors were multiplied. The main features of this two-step LPME for phenols lie in the following aspects. Firstly, the extraction can be accomplished within relatively short time (ca. 20min). Secondly, it was compatible with HPLC analysis, avoiding derivatization step that is generally necessary for GC analysis. Thirdly, high enrichment factors (296–954 fold) could be obtained for these analytes. Under the optimized conditions, the linearities were 10–1000, 1–500, 1–500, 5–500 and 1–500ng/mL for different phenols with all regression coefficients higher than 0.9985. The limits of detection were in the range from 0.3 to 3.0ng/mL for these analytes. Intra-and inter-day relative standard deviations were below 7.6%, indicating a good precision of the proposed method.