Solvent-assisted Dispersive Solid Phase Extraction Research Articles

Improved preconcentration workflow for organic explosive traces in aqueous samples using solvent-assisted dispersive solid-phase extraction

The present study deals with the development of a solvent-assisted dispersive solid phase extraction method for the extraction of HMX, RDX, and TNT from aqueous samples. Benzophenone and methanol were selected as explosives sorbent and dispersive solvent respectively. Extraction parameters like pH, extraction time, amount of sorbent, volume and type of the disperser solvent and centrifuge time were optimized. Dispersion of 0.5 mL dispersive solution (4% (w/v) benzophenone in methanol) was performed by injection into the 5 mL aqueous sample (pH=7) using a 1.0 mL syringe. After centrifuge, the extracted explosives were analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-Uv). The results indicated that the linear ranges with the correlation coefficients of 0.99 ≤ R2 were 1.6–204.6 μg L−1, 1.4–213.7 μg L−1 and 1.3–225.9 μg L−1 for HMX, RDX and TNT respectively. The limit of detection and limit of quantification obtained for each explosive were: 0.3 μg L−1 and 0.8 μg L−1 for HMX, 0.3 μg L−1 and 0.9 μg L−1 for RDX and 0.2 μg L−1 and 0.7 μg L−1 for TNT. Finally, the practical applicability of the developed method was evaluated for the extraction of some organic explosives in water samples followed their determination by HPLC-Uv.

High-throughput determination of oxidative stress biomarkers in saliva by solvent-assisted dispersive solid-phase extraction for clinical analysis

High-throughput determination of oxidative stress biomarkers in saliva by solvent-assisted dispersive solid-phase extraction for clinical analysis

Modified magnetic-based solvent-assisted dispersive solid-phase extraction: application to the determination of cortisol and cortisone in human saliva

A modification of magnetic-based solvent-assisted dispersive solid-phase extraction (M-SA-DSPE) has been employed for the determination of the biomarkers cortisol and cortisone in saliva samples. M-SA-DSPE is based on the dispersion of the sorbent material by using a disperser solvent like in dispersive solid phase extraction (SA-DSPE) but a magnetic sorbent is used like in magnetic dispersive solid-phase extraction (M-DSPE). Thus, the magnetic sorbent containing the target analytes is retrieved using an external magnet like in M-DSPE. Finally, the analytes are desorbed into a small volume of organic solvent for the subsequent chromatographic analysis. To this regard, a M-SA-DSPE-based method was developed using a magnetic composite as sorbent, made of CoFe2O4 magnetic nanoparticles embedded into a reversed phase polymer (Strata-XTM-RP), which exhibits affinity to the target analytes. Then, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was used to measure both analytes in the M-SA-DSPE extract. Under the optimized conditions, good analytical features were obtained: limits of detection of 0.029 ng mL−1 for cortisol and 0.018 ng mL−1 for cortisone, repeatability (as RSD) ≤ 10 %, and relative recoveries between 86 and 111 %, showing no significant matrix effects. Finally, the proposed method was applied to the analysis of saliva from different volunteers. This new methodology allows a fast and non-invasive determination of cortisol and cortisone, and it employs small amounts of sample, organic solvent and sorbent. Likewise, the sample treatment is minimum, since any supporting equipment (vortex, centrifuge, ultrasounds, etc.) is required.

Development of a New and Fast Extraction Method Based on Solvent-Assisted Dispersive Solid-Phase Extraction for Preconcentration and Trace Detection of Atrazine in Real Matrices.

Because of trace amounts of atrazine in water samples and the complexity of the matrix, direct trace monitoring of atrazine is not feasible by the abovementioned techniques. Hence, an efficient sample pretreatment procedure is necessary for cleanup and preconcentration of atrazine from sample matrices. In the current paper, a new and efficient sample preparation method named solvent-assisted dispersive solid-phase extraction (SA-DSPE), followed by HPLC-UV, was introduced for the monitoring of atrazine at trace levels in environmental water samples. In the present method, benzophenone was used as a sorbent for extraction of target molecules. For dispersing solid sorbents in sample solution, very low milligram amounts of benzophenone and dispersive solvent were mixed and fast-injected into the extraction media. A cloudy solution formed, and after interaction of atrazine and the dispersed solid sorbent, the cloudy solution was centrifuged. The extracted atrazine in the solid phase was dissolved in ethanol and analyzed by HPLC-UV. The introduced method showed a low method detection limit (0.1 μg/L), good precision (relative SD: 3.9-6.9%), and appropriate relative recoveries (95-105%). Within this study, a sensitive and reliable method for the quantification of atrazine in wastewater samples was successfully developed. The obtained figures of merit for the presented sample preparation method were appropriate. The applicability of the method for analysis of atrazine in real matrices was excellent.

Solvent-Assisted dispersive solid phase extraction of diclofenac from human serum and pharmaceutical tablets quantified by high-performance liquid chromatography

This study developed a novel solvent-assisted dispersive solid phase extraction (SADSPE) process in combination with HPLC for the determination of diclofenac (DIC) in tablets and human serum. This route required a few milligrams of benzophenone sorbent dispersed in the specimen solution using a disperser solvent giving rise to the formation of a cloudy solution which was then centrifuged. Ethanol was utilized for dissolving the analyte-enriched sorbent. The extract was then analyzed through the use of high-performance liquid chromatography (HPLC) equipped with UV-detection to quantify the DIC. Different parameters of the procedure including solution pH, sorbent type and content, disperser solvent type and volume, extraction time, and ionic strength were closely analyzed and optimized. The results of optimization were as follows: pH=2.5; 20 mg of benzophenone as sorbent, 1 mL of ethanol as disperser solvent, extraction time=30 s; and 0.5 mol L−1 of sodium chloride. The extracted analyte was dissolved by using 0.5 mL of ethanol. Optimized conditions led to the preconcentration factor of 40 and the limit of detection (LOD) of 0.47 µg L−1. The proposed method could be successfully employed for diclofenac determination in tablets and human serum samples (real and spiked samples), with recovery range of 96.7–97.9%.

Inside Front Cover: Development of a new solvent‐assisted dispersive solid‐phase extraction followed by ion mobility spectrometry for trace determination of organophosphorus pesticides in environmental water samples

DOI: 10.1002/sscp.201900031 The cover picture shows the extraction and monitoring of organophosphorus pesticides by the solvent-assisted dispersive solid-phase extraction method coupled with corona discharge ion mobility spectrometry.

In-syringe solvent-assisted dispersive solid phase extraction followed by flame atomic absorption spectrometry for determination of nickel in water and food samples

This study presents a new in-syringe solvent-assisted dispersive solid phase extraction (ISSADSPE) method for determination of nickel ions in water and food. The method involved dispersion of a few milligrams of sorbent in the sample solution inside the barrel of a syringe through application of a disperser solvent. In less than 1 min, the extraction equilibrium was achieved due to dispersion of the sorbent and high mass transfer rate. Afterwards, syringe membrane was employed to separate the dispersed sorbent from the solution. Then the ethanol was withdrawn by syringe membrane to dissolve the analyte-enriched sorbent. Flame atomic absorption spectroscopy was applied to assess the obtained extract. Effective factors such as the sorbent nature and amount, sample volume, pH, ligand concentration, type and volume of disperser solvent and eluent, ionic strength and extraction time were evaluated and optimized to improve the extraction efficiency. Under optimized conditions (pH = 8.0, ligand concentration = 2.0 × 10−4, sorbent = 10 mg of benzophenone, disperser solvent 500 μL of ethanol), the limit of detection and quantification were found to be 0.7 μg L−1 and 2.0 μg L−1, respectively. The calibration curve kept its linearity from 2 to150 μg L−1, with the square correlation coefficient of 0.997. The relative standard deviation was measured as 2.5% while the enrichment factor was assessed as 50. The proposed method was successfully applied for determination of nickel in environmental water, spinach and celery samples, with recovery range of 97–101%.

Application of solvent-assisted dispersive solid phase extraction combined with flame atomic absorption spectroscopy for the determination of trace amounts of Cadmium

Introduction: Cadmium is recognized worldwide as a toxic metal. In this study, Solvent-Assisted Dispersive Solid Phase Extraction (SA-DSPE) combined with Flame Atomic Absorption Spectrometry (FAAS), was used for determination of trace amounts of Cadmium (Cd-II)) in drinking water samples. Correspondence: Omid Rahmanian, PhD. Department of Environmental Health, Hormozgan University of Medical Sciences. Bandar Abbas, Iran Tel:+98 9177925646 Email: om.rahmanian@gmail.com Methods: In this approach, the dispersion of the sorbent was achieved by injecting a mixture of solution of the sorbent and dispersive solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution was centrifuged and the enriched Cd (II) in the sediment phase dissolved in ethanol and determined by FAAS. Some effective parameters for SA-DSPE, such as: pH, concentration of chelating agent, type and amount of sorbent, type and volume of dispersive solvent and salt effect were investigated and optimized. Results: Under the optimized conditions, the detection limit for Cd (II) ions was 0.6 ng mL-1. Calibration curve was made in the range of 1-300 ng mL-1, obtaining good linearity (R2=0.9930). Finally, SA-DSPE was successfully applied for trace determination of Cd (II) in drinking water samples. Conclusion: SA-DSPE is environment friendly and strongly against high contents of salt. The other benefits of the method are its simplicity, ease of operation, good precision, short extraction time, low cost, and a good enrichment factor.

Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples

In this research, a sample preparation method termed solvent-assisted dispersive solid-phase extraction (SA-DSPE) was applied. The used sample preparation method was based on the dispersion of the sorbent into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was received by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the diazinon, the cloudy solution was centrifuged and diazinon in the sediment phase dissolved in ethanol and determined by gas chromatography-flame ionization detector. Under the optimized conditions (pH of solution=7.0, Sorbent: benzophenone, 2%, Disperser solvent: ethanol, 500μL, Centrifuge: centrifuged at 4000rpm for 3min), the method detection limit for diazinon was 0.2, 0.3, 0.3 and 0.3μgL−1 for distilled water, lake water, waste water and urine sample, respectively. Furthermore, the pre-concentration factor was 363.8, 356.1, 360.7 and 353.38 in distilled water, waste water, lake water and urine sample, respectively. SA-DSPE was successfully used for trace monitoring of diazinon in urine, lake and waste water samples.

Trace monitoring of silver ions in food and water samples by flame atomic absorption spectrophotometry after preconcentration with solvent-assisted dispersive solid phase extraction

In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SADSPE) was developed. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by FAAS. Under the optimized conditions, the detection limit for silver ions was 0.8 μg L(-1). The relative standard deviations for six separate extraction experiments for determination of 5 and 200 μg L(-1) of silver ions was 3.4 and 3.1 %. The preconcentration factor was found to be 61.7. SADSPE was successfully applied for trace determination of silver ions in water and food samples.

Application of solvent-assisted dispersive solid phase extraction as a new, fast, simple and reliable preconcentration and trace detection of lead and cadmium ions in fruit and water samples

In this research, a new sample treatment technique termed solvent-assisted dispersive solid phase extraction (SA-DSPE) was developed. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by injecting a mixture solution of the sorbent and disperser solvent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy solution resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, the cloudy solution was centrifuged and the enriched analytes in the sediment phase dissolved in ethanol and determined by flame atomic absorption spectrophotometer. Under the optimized conditions, the detection limit for lead and cadmium ions was 1.2μgL−1 and 0.2μgL−1, respectively. Furthermore, the preconcentration factor was 299.3 and 137.1 for cadmium and lead ions, respectively. SA-DSPE was successfully applied for trace determination of lead and cadmium in fruit (Citrus limetta, Kiwi and pomegranate) and water samples.Finally, the introduced sample preparation method can be used as a simple, rapid, reliable, selective and sensitive method for flame atomic absorption spectrophotometric determination of trace levels of lead and cadmium ions in fruit and water samples.

Separation and Preconcentration of Trace Amounts of Lead from Water Samples Using Solvent-Assisted Dispersive Solid Phase Extraction

This paper describes a new approach for the preconcentration of lead (Pb2+) by solventassisted dispersive solid phase extraction (SADSPE) prior to analyzing by flame atomic absorption spectrometry (FAAS). In this method, the dispersion of the sorbent was achieved by injecting a solution of the sorbent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy state resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. Pb ions reacted with 1-(2-pyridylazo)-2-naphthole (PAN) as chelating agent to form a hydrophobic complex. After extraction, phase separation was performed by centrifugation and as a result, the enriched analyte in this demented phase could be determined by FAAS. Some parameters that influenced solvent-assisted dispersive solid phase extraction and subsequent determination were evaluated in detail. Under optimized conditions (pH 9, PAN concentration: 1.0 × 10-3 mol L-1, sorbent: 0.1% m/v 1,4-dichlorobenzene, disperser solvent: 0.5 mL ethanol), a preconcentration factor of 50 could be obtained, and the limit of detection (LOD) for lead was 1.3 μg L-1. Relative standard deviation for ten replicate determinations of the standard solution containing 20 μg L-1 lead was 5.0%. The proposed method was successfully applied for the determination of lead in water samples with satisfactory results.

Solvent-assisted dispersive solid phase extraction

In this research, a novel extraction technique termed solvent-assisted dispersive solid phase extraction (SADSPE) was developed for the first time. The new method was based on the dispersion of the sorbent into the sample to maximize the contact surface. In this method, the dispersion of the sorbent at a very low milligram level was achieved by injecting a solution of the sorbent into the aqueous sample. Thereby, a cloudy solution formed. The cloudy state resulted from the dispersion of the fine particles of the sorbent in the bulk aqueous sample. After extraction, phase separation was performed by centrifugation and the enriched analyte in the sedimented phase could be determined by instrumental methods. The performance of SADSPE was illustrated with the determination of the trace amounts of cobalt(II) as a test analyte in food and environmental water samples by using flame atomic absorption spectrometry detection. Some key parameters for SADSPE, such as sorbent selection and amount, type and volume of dispersive solvent, pH, chelating agent concentration, and salt concentration, were investigated. Under the most favorable conditions, good limit of detection (as low as 0.2µgL−1) and repeatability of extraction (RSD below 2.2%, n=10) was obtained. The accuracy of the method was tested with standard reference material (SRM-1643e and SRM-1640a) and spiked addition. The advantages of SADSPE method are simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.