Switchable Solvent-based Liquid Phase Microextraction Research Articles

Removal of two antidepressant active pharmaceutical ingredients from hospital wastewater by polystyrene-coated magnetite nanoparticles-assisted batch adsorption process.

This study employed simple polystyrene-coated magnetite nanoparticles (PS@MNPs)-assisted batch adsorption process for the removal of two antidepressant active ingredients (amitriptyline HCl and sertraline HCl) from hospital wastewater. Dominant parameters of the adsorption process including pH, adsorbent amount, and contact period were optimized through the univariate approach to enhance the adsorption efficiency. Upon reaching optimum adsorption conditions, equilibrium experiments were performed by spiking the adsorbates in hospital wastewater in the concentration range of 100-2000 μg/L. The concentrations of the adsorbates in the effluent were calculated using the matrix-matching calibration strategy to enhance the accuracy of quantification. A validated switchable solvent-based liquid phase microextraction (SS-LPME) method was employed to enrich the two active pharmaceutical ingredients (APIs) prior to sensitive determination with GC-MS (gas chromatography-mass spectrometry). The equilibrium data were mathematically modeled employing the Langmuir and Freundlich adsorption isotherm models. The isotherm constants were calculated, and the results showed that both the isotherm models fitted well with the experimental data. The efficient and simple batch adsorption strategy reported in this study was successfully employed to remove amitriptyline HCl and sertraline HCl from hospital wastewater at low concentrations.

Determination of rhodamine B in water and cosmetics by switchable solvent-based liquid phase microextraction with spectrophotometric determination

A microextraction method has been developed for the determination of rhodamine B (Rh-B) in water and cosmetics by separation and preconcentration with liquid microextraction based upon a switchable hydrophilic solvent and determination by spectrophotometry. The analyte was extracted into the triethylamine (TEA) phase using sodium hydroxide (NaOH) to convert protonated triethylamine carbonate (P-TEA-C) to triethylamine. Various analytical parameters such as the pH of the sample solution, extraction solvent volume, and sample volumes affecting the quantitative recovery values of rhodamine B were optimized. The limit of detection (LOD) and limit of quantification (LOQ) were 2.96 and 9.88 ng/mL, respectively. The developed method was successfully applied to the determination of rhodamine B and satisfactory recovery values were obtained. The developed approach is fairly fast and an environmentally friendly alternative for the separation and preconcentration of rhodamine B water and cosmetic samples.

Trace level determination of eleven nervous system-active pharmaceutical ingredients by switchable solvent-based liquid-phase microextraction and gas chromatography-mass spectrometry with matrix matching calibration strategy.

This study utilized switchable solvent liquid-phase microextraction (SS-LPME) to enrich eleven nervous system active pharmaceutical ingredients (APIs) from aqueous samples for their determination at trace levels by gas chromatography mass spectrometry. The analytes selected for the study included APIs utilized in antidepressant, antipsychotic, antiepileptic, and anti-dementia drugs. Parameters of the microextraction method including switchable solvent volume, concentration and volume of the trigger agent (sodium hydroxide), and sample agitation period were optimized univariately to boost extraction efficiency. Under the optimum conditions, the detection limits calculated for the analytes were in the range of 0.20-8.0ng/mL, and repeatability for six replicate measurements as indicated by percent relative standard deviation values were below 10%. Matrix matching calibration strategy was used to enhance quantification accuracy for the analytes. The percent recovery results calculated for the eleven analytes ranged between 86 and 117%.

A Switchable Solvent-Based Liquid Phase Microextraction Method for the Detection of Cadmium in Water Samples with Flame Atomic Absorption Spectrometry

The natural concentration of trace elements in water and soil depends on the geological, geomorphological, and climate characteristics of the region. The rapid increase of technology in recent years has increased concentrations of trace elements in nature. Separation and enrichment methods are needed to detect trace amounts of heavy metals that cannot be detected due to the detection limit of the instruments or the matrix effect in samples. Recently, low hazard solvents compatible with green chemistry have been used in preconcentration/separation studies of Cd(II). Switchable solvent-based liquid phase microextraction is an environmentally-friendly, simple, and fast procedure for the determination of Cd(II) ions in environmental samples combined with flame atomic absorption spectrometry (FAAS). The switchable polarity solvent was prepared with N,N-dimethyl-n-octylamine. 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol was used as the complexing agent. Important parameters such as pH, amount of switchable polarity solvent and NaOH, as well as ligand and sample volume, all of which might affect the microextraction efficiency were optimized. Under optimal experimental conditions, linear range was found to be between 5 and 500 µg/L. The limit of detection, preconcentration factor, and relative standard deviation were 0.89 μg/L, 150, and 3.2%, respectively. The accuracy of our method was confirmed by the analysis of certified reference material SPS-WW1 Batch 106 (Waste Waters). The developed procedure was successfully applied to determine the cadmium contents of environmental water samples. We believe that this environmentally-friendly method will be useful in detecting Cd(II) ions in water samples.

Determination of copper in traditional coffee pot water samples by flame atomic absorption spectrometry and matrix matching calibration strategy after switchable solvent based liquid-phase microextraction.

Traditional copper coffee pots are widely used in these modern times and daily consumption of coffee brewed in overused/old pots increases the risk of copper ingestion. This study employed a green switchable solvent-based liquid-phase microextraction (SS-LPME) method to isolate and preconcentrate copper from water boiled in coffee pots. Copper was determined by a flame atomic absorption spectrometry (FAAS) system coupled with a slotted quartz tube (SQT). 1,5-Diphenylcarbazone was added to aqueous samples to form a complex with copper before the extraction step. Box-Behnken experimental design was applied to select optimum conditions of the extraction method that were used to validate the analytical method. The limits of quantification and detection of the optimized SS-LPME-SQT-FAAS method were determined as 9.1 and 2.7μg/L, respectively. Water samples boiled in traditional coffee pots were spiked at different concentrations and analyzed to ascertain the method's accuracy and applicability to real samples. Satisfactory recovery results obtained in the range of 92-107% established good accuracy, and percent relative standard deviations lower than 8.0% also proved high precision.

Multivariate optimisation of a novel green microextraction method for Fe (III) determination in environmental samples by FAAS

ABSTRACT Industrial development has led to increased heavy metal pollution in bodies of water all over the world. Numerous methods are being developed with the aim of detecting and subsequently removing heavy metal ions from water with hopes of reversing pollution. Here, we present a novel and ecological switchable solvent-based liquid phase microextraction (SS-LPME) method that detects Fe (III) in water samples before they can be tested on flame atomic adsorption spectrometry. In this method, 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol was selected as a complexing agent and switchable polarity solvent was formulated with N, N-dimethyl-n-octylamine. Box–Behnken response surface design was used to investigate and optimise factors associated with the extraction recovery. When the optimal conditions were reached, a linear calibration curve was achieved at 0.05–400 µg L−1. The preconcentration factor was 200, the detection limit was 0.015 µg L−1 with the relative standard deviation (RSD) of 2.2% (at 30 µg L−1; n = 8). Water samples and wastewater reference material (SPSWW1) were used to test the applicability and success of the method.

Assessment of different isotope dilution strategies and their combination with switchable solvent-based liquid phase microextraction prior to the quantification of bisphenol A at trace levels via GC-MS

Different isotope dilution strategies were evaluated to quantify bisphenol A. High accuracy and precision were achieved by SS-LPME and ID4 combination.

Determination of Vitamin B12 and cobalt in egg yolk using vortex assisted switchable solvent based liquid phase microextraction prior to slotted quartz tube flame atomic absorption spectrometry

A switchable solvent based liquid phase microextraction (SS-LPME) has been proposed for the determination of cobalt in egg yolk and Vitamin B12 at trace levels. N,N-Dimethylbenzylamide (DMBA) was used as a switchable solvent and converted to protonated DMBA form by the addition of dry ice. Cobalt was complexed with 1,5-diphenylcarbazone (DPC) and extracted into the DMBA phase. After the extraction, HNO3 was added to increase nebulization efficiency of the DMBA phase. Slotted quartz tube (SQT) was combined with FAAS to enhance the detection power of the system when compared to the conventional FAAS. Under the optimum conditions, limit of detection values were recorded as 75 µg L−1 for FAAS, 33 µg L−1 for SQT-FAAS, 7.6 µg L−1 for SS-LPME-FAAS, and 2.3 µg L−1 for SS-LPME-SQT-FAAS. The developed method was applied for the determination of cobalt in egg yolk and Vitamin B12 and the recovery results were found in the range of 105–114% with 0.30–7.6 standard deviation values (n = 3).

Switchable solvent liquid-phase microextraction-gas chromatography-quadrupole isotope dilution mass spectrometry for the determination of 4‑n‑nonylphenol in municipal wastewater

Quadrupole isotope dilution mass spectrometry (ID4MS) and switchable solvent based liquid phase microextraction (SS-LPME) were combined to determine 4‑n‑nonylphenol (NP) in municipal waste water samples at trace levels. In this method, SS-LPME served as a preconcentration technique to reach trace levels for NP, while ID4MS was used as a measurement technique to improve accuracy and precision of the proposed method. A response surface methodology was performed to investigate the key parameters of SS-LPME method. Analysis of variance (ANOVA) was employed to assess the main experimental parameters and their interactions each other. Three calibration blends and one waste water sample blend were prepared with NP and 4‑n‑nonylphenol-D8 (NP-D8) for the application of SS-LPME-ID4MS. All the system parameters were optimized to improve the accuracy and detection power. Recovery of the SS-LPME-ID4MS method for waste water spiked at 40 ng g−1 was calculated as 101.5 ± 0.4%. This result does not only establish good applicability of the method to waste water, but also confirms the high accuracy and precision at a low concentration.

Application of switchable solvent-based liquid phase microextraction for preconcentration and trace detection of cadmium ions in baby food samples

In this paper, switchable solvent-based liquid phase microextraction was developed for preconcentration of cadmium ions and its detection by flame atomic absorption spectrometry. 2,9-dimethyl-1,10-phenanthroline (neocuproine) was used as a complexing agent in the developed sample preparation method. Conversion features of triethylamine and protonated triethylamine bicarbonate were used as a switchable solvent pair. Protonated triethylamine bicarbonate as polar form of switchable polarity solvent was successfully synthesized from triethylamine via proton transfer reaction and used for microextraction of hydrophobic cadmium complex with 2,9-dimethyl-1,10-phenanthroline at pH 7.0. The factors influencing the extraction procedure were investigated and optimized. Under the optimized conditions, limit of detection, limit of quantification, and enrichment factor for the proposed method were 0.02, 0.1 µg L−1, and 54.2, respectively. The calibration curve was linear in the range of 0.1–60 µg L−1 with a correlation of determination (r 2) of 0.99. The relative standard deviation for determination of 40 µg L−1 of Cd (II) was 3.1% (n = 6). The intraday and inter-day precisions for real samples analysis were in the range of 4.4–5.6 and 4.9–5.7%, respectively. The proposed method was applied for the determination of cadmium in baby food samples with satisfactory analytical results. In comparison with other methods, the proposed method is very easy, rapid, simple, and sensitive for determination of cadmium at trace levels in complex matrices.

A fully automated effervescence-assisted switchable solvent-based liquid phase microextraction procedure: Liquid chromatographic determination of ofloxacin in human urine samples

A novel fully automated effervescence-assisted switchable solvent-based liquid phase microextraction procedure has been suggested. In this extraction method, medium-chain saturated fatty acids were investigated as switchable hydrophilicity solvents. The conversion of fatty acid into hydrophilic form was carried out in the presence of sodium carbonate. The injection of sulfuric acid into the solution decreased the pH value of the solution, thus, microdroplets of the fatty acid were generated. Carbon dioxide bubbles were generated in-situ, and promoted the extraction process and final phase separation. The performance of the suggested approach was demonstrated by the determination of ofloxacin in human urine samples using high-performance liquid chromatography with fluorescence detection. This analytical task was used as a proof-of-concept example. Under the optimal conditions, the detector response of ofloxacin was linear in the concentration ranges of 3·10−8−3·10−6 mol L−1. The limit of detection, calculated from a blank test based on 3σ, was 1·10−8 mol L−1. The results demonstrated that the presented approach is highly cost-effective, simple, rapid and environmentally friendly.

Switchable solvent-based liquid phase microextraction of copper(ii): optimization and application to environmental samples

A switchable solvent-based liquid phase microextraction (SS-LPME) procedure has been established for the preconcentration of copper prior to its determination by microsampling flame atomic absorption spectrometry (FAAS).