Estimation of Some Useful Drugs in Water, Urine, and Medical Formulations Following Conventional and Modified Dispersive Microextraction Coupled with HPLC-UV

Dispersive Liquid-Liquid Microextraction (DLLME) coupled with high-performance liquid chromatography-ultraviolet spectroscopy was developed, as a fast and precise operation, for extractive recovery and estimation of two pharmaceuticals viz. moxifloxacin and galantamine, from water, urine, and medical formulations. The process was investigated for Extraction (ES) and Dispersive Solvent (DS) as well as pH, temperature, and salt concentration. Extraction was found effective using methanol (CH3OH), as the DS, employing 1,1,2,2-tetrachloroethane (C2H2Cl4) and chloroform (CHCl3), as the ES, for moxifloxacin and galantamine respectively. The optimum pH was found to be 6.9 for moxifloxacin and 10.2 for galantamine. Temperature and salt were found to have some influence on the extraction efficiency of moxifloxacin but insignificant for galantamine. An improvement of the operation in terms of the Extraction efficiency (ER %), Preconcentration Factor (PF), thermodynamic feasibility, and greenness were achieved during surfactant aided DLLME (SDS-DLLME), where anionic surfactant (Sodium Dodecyl Sulphate (SDS)) was employed and no DS was required. Interestingly, the volume requirement for ES was found less, compared to that in the conventional DLLME, without compromising the performance. Moreover, quantitative recovery of both the drugs was achieved using a single ES. Thus, mutual separation and simultaneous determination of moxifloxacin and galantamine may be designed. A two-phase separation with concomitant enrichment of the solute in the sediment phase occurred. The drugs in the sediment phase, on subsequent dilution with methanol, were determined using the High Performance Liquid Chromatography-Ultraviolet (HPLC-UV) system. The negative free energy changes for the operation indicated that the process was thermodynamically feasible. The process was found to be effective for the spiked recovery of the studied drugs from real samples viz, water, human urine, and commercial medical formulations.

Dimercaptosuccinic Acid Functionalized Polystyrene Column for Trace Concentration Determination of Heavy Metal Ions: Experimental and Theoretical Calculation Studies

Metal ion studies in wastewater are required on a regular basis for environmental monitoring and assessment. Less metal ion concentrations and the interference from complex sample matrices remains challenging for instrumental quantification. Herein, we proposed a fix-bed solid phase extraction method, consisting of a newly prepared dimercaptosuccinic acid functionalized polystyrene beads. The ligand forms stable complex with Hg(II), Pb(II), and Cd(II), evident by experimental as well as density functional theory. The metal-ligand stabilization energy calculations, suggested the higher selectivity of polystyrene dimercaptosuccinic acid (PSDMSA) toward Pb(II) compared to Cd(II) and Hg(II). The prepared adsorbent was utilized to enrich Hg(II), Pb(II), and Cd(II) ions from environmental samples. Column parameters were studied in detail and optimized accordingly. The preconcentration factor for Hg(II), Pb(II), and Cd(II) were found to be 900, with the preconcentration limit of 0.74 µg L−1. The detection limit for Pb(II), Cd(II), and Hg(II) ions was found to be 1.3 ± 0.2, 1.5 ± 0.3, and 1.8 ± 0.3 ng L−1, respectively. The method accuracy was tested against systematic and continuous errors by standard addition method (<5% RSD). Real samples was successfully analyzed following the proposed method.

Extraction of Pregabalin in Urine Samples Using a Sulfonated Poly(ether ether ketone) Membrane

In this work, a simple polymer-assisted microextraction technique was developed to determine pregabalin (an anticonvulsant drug) in the urine sample. A sulfonated poly(ether ether ketone) membrane was used as a sorbent for pregabalin extraction, and the extraction performance was compared with that of the conventional polydimethylsiloxane membrane. The extraction device is free moving and tumbles continuously throughout the stirred sample solution during extraction to enhance the extraction efficiency. The electrostatic interactions between the sulfonic-acid-functionalized polymeric membrane and the amine group in the pregabalin molecule facilitate higher preconcentration factor at a shorter extraction time. Optimizing conditions of the extraction method were investigated to obtain higher extraction efficiency. The developed method exhibited good linearity in the range of 0.05 to 2 µg/mL with a correlation of determination (r2) 0.9998, acceptable limits of detection, limits of quantification, and preconcentration factor of 105-fold. The within-day and between-day precisions of pregabalin were lower than 7% relative standard deviations. Pregabalin was extracted from urine samples with recoveries of >92%, and no significant matrix effects were observed.

Origami paper-based sample preconcentration using sequentially driven ion concentration polarization

To overcome the hurdles of the ICP-based preconcentrator (i.e., instability and low efficiency) under physiological conditions, we proposed a novel approach by using a sequentially driven ICP process, showing a 13-fold preconcentration factor (PF) in human serum.

Magnetic Solid-Phase Extraction Based on Fe3O4/g-C3N4 Nanocomposite for the Determination of Polychlorinated Biphenyls and Polychlorinated Diphenyl Ethers in Environmental Waters

The graphitic carbon nitride (g-C3N4) and the Fe3O4/g-C3N4 magnetic materials were synthesized in this paper. The structures of the materials were confirmed by a series of analysis. The Fe3O4/g-C3N4 was then used as a sorbent to adsorb polychlorinated diphenyl ethers and polychlorinated biphenyls. Different extraction conditions were examined, including adsorbent amount, salinity, pH of the sample matrix, adsorption time, reaction temperature, elution solvent and preconcentration factor. The maximum recoveries were obtained by employing methanol to desorb pollutants on 40.0 mg Fe3O4/g-C3N4 in 120.0 mL environmental water with a salinity of 5% (w/v) at a pH of 7 at 25 °C within 10 min. Using the optimized parameters, the detection limits of the method are between 0.01 and 0.04 μ · L−1 with a satisfying linear relationship. The adsorbent can be recycled at least 10 times with no significant reduction in the extraction efficiency.

3D Nanoarchitecture of Polyaniline-MoS2 Hybrid Material for Hg(II) Adsorption Properties

We report the facile hydrothermal synthesis of polyaniline (PANI)-modified molybdenum disulfide (MoS2) nanosheets to fabricate a novel organic–inorganic hybrid material. The prepared 3D nanomaterial was characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction studies. The results indicate the successful synthesis of PANI–MoS2 hybrid material. The PANI–MoS2 was used to study the extraction and preconcentration of trace mercury ions. The experimental conditions were optimized systematically, and the data shows a good Hg(II) adsorption capacity of 240.0 mg g−1 of material. The adsorption of Hg(II) on PANI–MoS2 hybrid material may be attributed to the selective complexation between the–S ion of PANI–MoS2 with Hg(II). The proposed method shows a high preconcentration limit of 0.31 µg L−1 with a preconcentration factor of 640. The lowest trace Hg(II) concentration, which was quantitatively analyzed by the proposed method, was 0.03 µg L−1. The standard reference material was analyzed to determine the concentration of Hg(II) to validate the proposed methodology. Good agreement between the certified and observed values indicates the applicability of the developed method for Hg(II) analysis in real samples. The study suggests that the PANI–MoS2 hybrid material can be used for trace Hg(II) analyses for environmental water monitoring.

Trace Determination of Tamoxifen using Optimized Solvent Bar Microextraction and HPLC-UV

Background: Tamoxifen (Soltamox) is an antineoplastic agent and an estrogen receptor antagonist used to treat breast cancer, but have severe side effects such as hot flashes, vaginal discharge, etc. Dose monitoring is a necessity for optimum treatment, to prevent severe adverse effects. Methods: In this study, the solvent bar microextraction method (SBME) was used for preconcentration and microextraction coupled with High-performance liquid chromatography-ultraviolet (HPLC-UV) analysis of tamoxifen. Results: The limit of detection and limit of quantification were 13.3 and 40 μgL-1, respectively. The linear range was between 40 and 10000 μgL-1 with a correlation coefficient of 0.999. The enrichment factor was 169 and the relative standard deviation within-day and between-day were 3.6 and 4.0, respectively. Conclusion: The use of sensitive SBME method coupled with HPLC-UV analysis for detection of tamoxifen at trace level proved to be successful, offering a desirable preconcentration factor, and a costeffective and green set-up for determining its rate of elimination from cancer patients and wastewater.

Facile synthesis of a modified HF-free MIL-101(Cr) nanoadsorbent for extraction nickel in water and wastewater samples

A novel sorbent based on MIL-101(Cr) nanoadsorbent as MOF structure was used for nickel extraction from water and wastewater samples. In this study, 30 mg of MIL-101(Cr) nanoadsorbent dispersed in 50 mL of water or wastewater samples, after sonication and adjusting pH =8.5, the nickel ions was extracted by carboxyl groups of terephthalic acid (MOF-(C6H4 (COO)-2…. Ni2+) by dispersive suspension micro solid phase extraction (DS-μ-SPE).The MOF was separated from liquid phase with filter membrane (0.2 μm), eluted with 0.5 mL of nitric acid as back-extraction solution and finally, the nickel concentration in eluent determined by atom trap-flame atomic absorption spectrometry (AT-FAAS) after dilution with DW up to 1 mL.The LOD, the linear range and preconcentration factor were achieved 1.5 µg L−1, 5-160 µg L−1 and 49.7, respectively.The absorption capacity of MOF for nickel was obtained 136.8 mg g-1.The results of procedure were validated by spiking of samples and ET-AAS analyzer.

GREEN VORTEX-ASSISTED IONIC LIQUID-BASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION FOR ENRICHMENT AND DETERMINATION OF CADMIUM AND LEAD IN WATER, VEGETABLES AND TOBACCO SAMPLES

Objective: An eco-friendly, simple and sensitive vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction method (VA-IL-DLLµE) has been proposed to enrich and determine trace levels of cadmium (Cd2+ ) and lead (Pb2+ ) ions in water, vegetables and tobacco samples, prior to its FAAS determination. Methods: The proposed method based on utilization of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for both ions after the complexation with 4,5-dihydroxy-3-phenylazo-2,7-naphthalenedisulfonic acid, disodium salt (Chromotrope 2R) at pH 6.5. The impact of different analytical parameters on microextraction efficiency was optimized. Results: In the ranges of 1.0–300 and 2.0-400 μg/ml, the calibration graphs were linear. The limits of detection were 0.3 and 0.6 μg/ml for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 100. The relative standard deviation (RSD %)<3.0%, which indicates the proposed method has high precision. Conclusion: The proposed VA-IL-DLLµE method was developed and applied for the estimation of Cd2+ and Pb2+ ion content in various water, vegetables and tobacco samples, and satisfactory results were obtained. The obtained recovery values showed good agreement with the certified values.

Simultaneous Spectrophotometric Determination of Brilliant Blue and Tartrazine in Diverse Sample Matrices after Solid Phase Extraction

Background Brilliant blue (BB) and tartrazine (TZ) are manufactured from petroleum and its products. These are the most popular consumed food dyes and are widely used in foodstuffs. Therefore, overuse of these dyes in foodstuffs and consumption of excessive amounts of these dyes can lead to health problems in humans. Objective The aim of this study was to develop a simple separation and preconcentration method for simultaneous spectrophotometric determination of BB and TZ dyes. Methods A column solid-phase separation extraction method combined with UV-Vis spectrophotometry was preferred and developed for single and simultaneous determination of BB and TZ dyes. Results The preconcentration factor was obtained as 80. Relative standard deviations were below than 4%. Detection limits of the method were determined as 0.29 and 1.21 µg/L for BB and TZ, respectively. Recovery values were obtained between 95–99% and 96–100% for BB and TZ, respectively. 10.9–235.7 µg/g and 1.7–8.0 µg/mL of BB contents of real samples were determined for solid and liquid samples, respectively. TZ concentrations of solid and liquid samples were ranged between 18.7–220.7 µg/g and 5.9–7.5 µg/mL, respectively. Conclusions Quantitative extraction results and satisfactory recovery values showed that method was successful and applicable for determination of BB and TZ concentrations in real pharmaceutical, industrial, and foodstuff samples. Highlights The method has exhibited a high preconcentration factor and effective separation against to matrix ions. The method did not need an experienced operator with high operation experience. Elution solvent can be chosen according to the availability of the chemicals in the laboratory and cheapness of the chemicals.