scholarly journals Bar Adsorptive Microextraction Coated with Carbon-Based Phase Mixtures for Performance-Enhancement to Monitor Selected Benzotriazoles, Benzothiazoles, and Benzenesulfonamides in Environmental Water Matrices

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2133
Author(s):  
Samir M. Ahmad ◽  
Bruno B.C. Calado ◽  
Mariana N. Oliveira ◽  
Nuno R. Neng ◽  
J.M.F. Nogueira
Keyword(s):  
High Performance ◽  
Performance Enhancement ◽  
Aqueous Media ◽  
Environmental Water ◽  
Experimental Conditions ◽  
Target Analytes ◽  
Relative Standard ◽  
Environmental Water Matrices ◽  
Array Detection ◽  
Carbon Based

In the present work we propose, for the first time, bar adsorptive microextraction coated with carbon-based phase mixtures, followed by microliquid desorption and high performance liquid chromatography-diode array detection (BAμE-μLD/HPLC-DAD) analysis, to enhance the performance of the determination of traces of benzotriazoles (BTRs), benzothiazoles (BTs), and benzenesulfonamide derivatives (BSDs) in environmental water matrices. Assessing six carbon-based sorbents (CA1, CN1, B test EUR, SX PLUS, SX 1, and R) with different selectivity properties allowed us to tailor the best phase mixture (R, 12.5%/CN1, 87.5%) that has convenient porosity, texture, and surface chemistry (pHPZC,mix ~6.5) for trace analysis of benzenesulfonamide, 1-hydroxybenzotriazole, 1H-benzotriazole, 5-methyl-1H-benzotriazole, benzothiazole, and 1,3-benzothiazol-2-ol chemicals in aqueous media. Optimized experimental conditions provided average recoveries ranging from 37.9% to 59.2%, appropriate linear dynamic ranges (5.0 to 120.0 µg L−1; r2 ≥ 0.9964), limits of detection between 1.0 and 1.4 μg L−1, and good precisions (relative standard deviation (RSD) ≤ 9.3%). The proposed methodology (BAμE(R, 12.5%/CN1, 87.5%)-μLD/HPLC-DAD) also proved to be a suitable sorption-based static microextraction alternative to monitor traces of BTRs, BTs, and BSDs in rain, waste, tap, and estuarine water samples. From the data obtained, the proposed approach showed that the BAμE technique with the addition of lab-made devices allows users to adapt the technique to use sorbents or mixtures of sorbents with the best selectivity characteristics whenever distinct classes of target analytes occur simultaneously in the same application.

scholarly journals Multi-Spheres Adsorptive Microextraction (MSAμE)—Application of a Novel Analytical Approach for Monitoring Chemical Anthropogenic Markers in Environmental Water Matrices

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 931 ◽  
Author(s):  
Ana Silva ◽  
Nuno Neng ◽  
José Nogueira
Keyword(s):  
High Performance ◽  
Activated Carbons ◽  
Standard Addition ◽  
Environmental Water ◽  
Environmental Matrices ◽  
Experimental Conditions ◽  
Anthropogenic Markers ◽  
Feasible Alternative ◽  
Environmental Water Matrices ◽  
Wastewater Samples

Multi-spheres adsorptive microextraction using powdered activated carbons (ACs) was studied as a novel enrichment approach, followed by liquid desorption and high-performance liquid chromatography with diode array detection (MSAµE(AC)-LD/HPLC-DAD) to monitor caffeine (CAF) and acetaminophen (ACF) traces in environmental matrices. In this study, commercial activated carbons (N, NOX, and R) were tested, with the latter showing a much better performance for the analysis of both anthropogenic drugs. The main parameters affecting the efficiency of the proposed methodology are fully discussed using commercial AC(R). Textural and surface chemistry properties of the ACs sample were correlated with the analytical results. Assays performed on 30 mL of water samples spiked at 10 µg L−1 under optimized experimental conditions, yielding recoveries of 75.3% for ACF and 82.6% for CAF. The methodology also showed excellent linear dynamic ranges for both drugs with determination coefficients higher than 0.9976, limits of detection and quantification of 0.8–1.2 µg L−1 and 2.8–4.0 µg L−1, respectively, and suitable precision (RSD < 13.8%). By using the standard addition method, the application of the present method to environmental matrices, including superficial, sea, and wastewater samples, allowed very good performance at the trace level. The proposed methodology proved to be a feasible alternative for polar compound analysis, showing to be easy to implement, reliable, and sensitive, with the possibility to reuse and store the analytical devices loaded with the target compounds for later analysis.

scholarly journals Influence of Ligand Functionalization of UiO-66-Based Metal-Organic Frameworks When Used as Sorbents in Dispersive Solid-Phase Analytical Microextraction for Different Aqueous Organic Pollutants

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2869 ◽  
Author(s):  
Iván Taima-Mancera ◽  
Priscilla Rocío-Bautista ◽  
Jorge Pasán ◽  
Juan Ayala ◽  
Catalina Ruiz-Pérez ◽  
...  
Keyword(s):  
High Performance ◽  
Solid Phase ◽  
Metal Organic Frameworks ◽  
Aqueous Sample ◽  
Optimization Study ◽  
Relative Standard ◽  
Polycyclic Aromatic ◽  
Metal Organic ◽  
Array Detection ◽  
First Time

Four metal-organic frameworks (MOFs), specifically UiO-66, UiO-66-NH2, UiO-66-NO2, and MIL-53(Al), were synthesized, characterized, and used as sorbents in a dispersive micro-solid phase extraction (D-µSPE) method for the determination of nine pollutants of different nature, including drugs, phenols, polycyclic aromatic hydrocarbons, and personal care products in environmental waters. The D-µSPE method, using these MOFs as sorbents and in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD), was optimized. The optimization study pointed out to UiO-66-NO2 as the best MOF to use in the multi-component determination. Furthermore, the utilization of isoreticular MOFs based on UiO-66 with the same topology but different functional groups, and MIL-53(Al) to compare with, allowed us for the first time to evaluate the influence of such functionalization of the ligand with regards to the efficiency of the D-µSPE-HPLC-DAD method. Optimum conditions included: 20 mg of UiO-66-NO2 MOF in 20 mL of the aqueous sample, 3 min of agitation by vortex and 5 min of centrifugation, followed by the use of only 500 µL of acetonitrile as desorption solvent (once the MOF containing analytes was separated), 5 min of vortex and 5 min of centrifugation. The validation of the D-µSPE-HPLC-DAD method showed limits of detection down to 1.5 ng·L−1, average relative recoveries of 107% for a spiked level of 1.50 µg·L−1, and inter-day precision values with relative standard deviations lower than 14%, for the group of pollutants considered.

Online Determination of Anionic Surfactant in Environmental Water

2012 ◽  
Vol 610-613 ◽  
pp. 1113-1116
Author(s):  
Liang Wei ◽  
Yi Chun Dai
Keyword(s):  
Anionic Surfactant ◽  
Sodium Dodecyl ◽  
Environmental Water ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Ethyl Violet ◽  
Relative Standard ◽  
Potassium Hydrogen ◽  
Standard Solution

It was found that ethyl violet can react with sodium dodecyl benzene sulfate (SDBS) to form ion associates in pH 2.2 ~ 2.8 of buffer solution of potassium hydrogen phthalate and hydrochloric acid in the presence of polyvinyl alcohol. Based on this, a method was proposed for online determination of anionic surfactant in environmental waterby. Under the optimum experimental conditions, Beers law was obeyed in the concentration range of 80 µg/L ~ 3500 µg/L of anionic surfactant (SDBS). The relative standard deviation of 2.1% was was obtained by injecting 800 µg/L of sodium dodecyl benzene sulfate standard solution (n=10). The detection limit calculated from three times of the average background noise was 4.39 µg/L. The proposed method had been applied successfully to the determination of anionic surfactant in environmental water and the results showed good agreement with that of the standard method.

Simultaneous Determination of Four Plant Hormones in Soil by Ultrasound-Assisted Ionic Liquid Based Dispersive Liquid-Liquid Microextraction

2014 ◽  
Vol 675-677 ◽  
pp. 181-184 ◽  
Author(s):  
Gui Qi Huang ◽  
She Ying Dong ◽  
Zhen Yang ◽  
Ting Lin Huang
Keyword(s):  
Ionic Liquid ◽  
Plant Hormones ◽  
High Performance ◽  
Extraction Solvent ◽  
Target Analytes ◽  
Relative Standard ◽  
Ultrasound Assisted ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

An ultrasound-assisted ionic liquid based dispersive liquid-liquid microextraction (UA-IL-DLLME) was developed for the determination of four plant hormones (6-benzyladenine (6-BA), kinetin (6-KT), 2, 4-dichlorophenoxy acetic acid (2, 4-D) and uniconazole (UN)) in soil, using high performance liquid chromatography (HPLC)-diode array detection (DAD). Several important parameters including the type and volume of extraction solvent, the volume of disperser solvent, ultrasound time, pH of the solution and salt effect were studied and optimized. Under optimum conditions, the limits of detections (LODs) for the target analytes were in the range of 0.002-0.01 μg g-1. And satisfactory recoveries of the target analytes in the soil samples were 79.3-96.7 %, with relative standard deviations (RSD, n=5) that ranged from 4.3 to 6.7%.

scholarly journals Column High-Performance Liquid Chromatographic Determination of Norfloxacin and Its Main Impurities in Pharmaceuticals

2008 ◽  
Vol 91 (2) ◽  
pp. 332-338 ◽  
Author(s):  
Branislava Mielji ◽  
Gordana Popovi ◽  
Danica Agbaba ◽  
Slavko Markovi ◽  
Breda Simonovska ◽  
...  
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Array Detector ◽  
Chromatographic Separations ◽  
Experimental Conditions ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A gradient reversed-phase column high-performance liquid chromatographic method was developed for the detection and quantification of norfloxacin and its major impurities in norfloxacin-containing pharmaceuticals. Chromatographic separations were performed under the following experimental conditions: column, Zorbax SB RP-18 (5 m, 250 4.6 mm); injection volume, 20 L; mobile phase, 0.05 M NaH2PO4 (pH 2.5)acetonitrile (87 + 13) for 16 min and (58 + 42) for 9 min (stepwise gradient); and flow rate, 1.3 mL/min. All analyses were performed at 25C, and the eluate was monitored at 275 nm using a diode array detector. Linearity (correlation coefficient = 0.999), recovery (99.3101.8), relative standard deviation (0.20.7), and quantitation limit (0.120.47 g/mL) were evaluated and found to be satisfactory. The method is simple, rapid, and convenient for purity control of norfloxacin in both raw materials and dosage forms.

scholarly journals Simultaneous quantifications of four purine derivatives biomarkers in cow milk by SPE HPLC-DAD

2021 ◽  
Vol 39 (No. 2) ◽  
pp. 122-130
Author(s):  
Mihaela Vlassa ◽  
Miuta FILIP ◽  
Catalin DRAGOMIR
Keyword(s):  
Uric Acid ◽  
High Performance ◽  
Solid Phase ◽  
Cow Milk ◽  
Good Precision ◽  
Purine Derivatives ◽  
Buffer Solution ◽  
Solution Ph ◽  
Relative Standard ◽  
Array Detection

In this study, simultaneous quantification of allantoin, uric acid, xanthine, and hypoxanthine in cow milk by solid phase extraction (SPE) and high performance liquid chromatography-diode array detection (HPLC-DAD) method was perform. Five different SPE cartridges were tested in order to evaluate the isolation of purine derivatives (PD) from cow milk. Chromatography was carried out on ODS-2 Hypersil column and 0.05 M (NH<sub>4</sub>)<sub>2</sub>HPO<sub>4</sub> buffer solution (pH = 7.76) as mobile phase. The HPLC-DAD validated method showed a linearity with regression coefficients higher than 0.999 and the limits of detection and quantification with values in the range 0.09–0.74 µg mL<sup>–1</sup> and 0.27–2.24 µg mL<sup>–1</sup>, respectively. The method showed good precision with a relative standard deviation (RSD) below 4.48%, while the accuracy ranged from 95.34 to 104.47% for all analytes. The best recovery degree of PD by SPE were obtained on Strata SCX cartridge for xanthine (87.79%) and hypoxanthine (89.02%); on Strata NH<sub>2</sub> for allantoin (35.09%) and on Strata C8 for uric acid (101.08%). Finally, the HPLC-DAD method with SPE on SCX cartridges was applied to quantify the PD in a batch of thirty cow milk samples.

Hollow Fiber Liquid Phase Microextraction as an Advantageous Approach for Preconcentraton of Malachite Green in Environmental Water

2013 ◽  
Vol 726-731 ◽  
pp. 1491-1495
Author(s):  
Zhen Chang ◽  
Kai Zhou ◽  
Liu Qing Yang ◽  
Xiang Yang Wu ◽  
Zhen Zhang
Keyword(s):  
Liquid Phase ◽  
Malachite Green ◽  
Hollow Fiber ◽  
High Performance ◽  
Environmental Water ◽  
Extraction Time ◽  
Two Phase ◽  
Liquid Phase Microextraction ◽  
Relative Standard ◽  
Donor Phase

A two-phase hollow fiber liquid phase microextraction (HF-LPME) by coupling with high performance liquid chromatography (HPLC) was developed to analyze malachite green (MG) in environmental water. In this method, 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MI[PF6]) was selected as extraction agent, and several parameters (sample pH, salinity, extraction time, shaking rate, volume of donor phase) that could affect extraction performance were investigated. Under the optimal extraction conditions (sample pH, 5; salinity, 4% sodium chloride; extraction time, 6 h; shaking rate, 200 rpm; volume of donor phase, 200 mL), the established method showed excellent characters as: high enrichment factor (1193), wide linear range (0.2-100 μg L-1), low detection limit (0.1 μg L-1), good reproducibility (relative standard deviation, RSD 8.4%, n= 5) and satisfactory recovery (102.8%, n= 5). The approach was applied in real water samples analysis, which indicated that it has great potentials for rapidly monitoring low concentration of MG in environmental waters.

scholarly journals An Electrochemiluminescence Sensor Based on Nafion/Magnetic Fe3O4 Nanocrystals Modified Electrode for the Determination of Bisphenol A in Environmental Water Samples

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2537 ◽  
Author(s):  
Jiye Chai ◽  
Xinru Yu ◽  
Jian Zhao ◽  
Aili Sun ◽  
Xizhi Shi ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Water Samples ◽  
Supporting Electrolyte ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Environmental Water ◽  
Experimental Conditions ◽  
Quenching Effect ◽  
Relative Standard

The well-dispersive and superparamagnetic Fe3O4-nanocrystals (Fe3O4-NCs) which could significantly enhance the anodic electrochemiluminescence (ECL) behavior of luminol, were synthesized in this study. Compared to ZnS, ZnSe, CdS and CdTe nanoparticles, the strongest anodic ECL signals were obtained at +1.6 V on the Fe3O4-NCs coated glassy carbon electrode. The ECL spectra revealed that the strong ECL resonance energy transfer occurred between luminol and Fe3O4-NCs. Furthermore, under the optimized ECL experimental conditions, such as the amount of Fe3O4-NCs, the concentration of luminol and the pH of supporting electrolyte, BPA exhibited a stronger distinct ECL quenching effect than its structural analogs and a highly selective and sensitive ECL sensor for the determination of bisphenol A (BPA) was developed based on the Fe3O4-NCs. A good linear relationship was found between the ECL intensity and the increased BPA concentration within 0.01–5.0 mg/L, with a correlation coefficient of 0.9972. The detection limit was 0.66 × 10−3 mg/L. Good recoveries between 96.0% and 105.0% with a relative standard deviation of less than 4.8% were obtained in real water samples. The proposed ECL sensor can be successfully employed to BPA detection in environmental aqueous samples.

Adsorptive cathodic stripping voltammetric determination of curcumin in turmeric and human serum

2011 ◽  
Vol 76 (3) ◽  
pp. 143-157 ◽  
Author(s):  
Mohammad Bagher Gholivand ◽  
Farhad Ahmadi ◽  
Alireza Pourhossein
Keyword(s):  
Human Serum ◽  
High Performance ◽  
Supporting Electrolyte ◽  
Cathodic Peak ◽  
Experimental Conditions ◽  
Accumulation Time ◽  
Accumulation Potential ◽  
Relative Standard ◽  
Cathodic Stripping

A simple, rapid, reliable and fully validated differential pulse adsorptive cathodic stripping voltammetric procedure has been developed for determination of the curcumin in human serum and turmeric, based on its electrochemical reduction at a hanging mercury drop electrode. The Britton–Robinson (BR) buffer of pH 9.5 was found to be reasonable as a supporting electrolyte for the assay of the compound. The effect of different parameters, such as pH, accumulation potential and accumulation time, on the sensitivity of method was evaluated. Under the optimized conditions (accumulation potential –0.3 V, accumulation time 50 s, BR buffer pH 9.5), curcumin was generated one irreversible cathodic peak. This cathodic peak showed a linear dependence on the concentration of curcumin over the range of 5.0 × 10–9–2.8 × 10–7 mol l–1. The obtained detection limit under the optimal experimental conditions is 1.5 × 10–9 mol l–1 after 50 s of the accumulation time. The relative standard deviation of 1.12% for concentration of 5.0 × 10–8 mol l–1 with 50 s accumulation time was obtained. The procedure was used successfully to the assay of the curcumin in turmeric and spiked human serum, and a good agreement was obtained between the results of the proposed method and high performance liquid chromatography (HPLC) analysis.

scholarly journals A QuEChERS-HPLC-MS/MS Method with Matrix Matching Calibration Strategy for Determination of Imidacloprid and Its Metabolites in Procambarus clarkii (Crayfish) Tissues

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 274
Author(s):  
Qiuhong Yang ◽  
Xiaohui Ai ◽  
Jing Dong ◽  
Yongtao Liu ◽  
Shun Zhou ◽  
...  
Keyword(s):  
High Performance ◽  
Procambarus Clarkii ◽  
Rapid Determination ◽  
Multiple Reaction Monitoring ◽  
Negative Ion ◽  
Experimental Conditions ◽  
Neutral Alumina ◽  
Relative Standard ◽  
Primary Secondary Amine

We developed a method for determination of imidacloprid and its metabolites 5-hydroxy imidacloprid, olefin imidacloprid, imidacloprid urea and 6-chloronicotinic acid in Procambarus clarkii (crayfish) tissues using quick, easy, cheap, effective, rugged, and safe (QuEChERS) and high-performance liquid chromatography-triple quadrupole mass spectrometry. Samples (plasma, cephalothorax, hepatopancrea, gill, intestine, and muscle) were extracted with acetonitrile containing 0.1% acetic acid and cleaned up using a neutral alumina column containing a primary secondary amine. The prepared samples were separated using reverse phase chromatography and scanned in the positive and negative ion multiple reaction-monitoring modes. Under the optimum experimental conditions, spiked recoveries for these compounds in P. clarkii samples ranged from 80.6 to 112.7% with relative standard deviations of 4.2 to 12.6%. The limits of detection were 0.02–0.5 μg·L−1, the limits of quantification were 0.05–2.0 μg·L−1 and the method of quantification was 0.05–2.0 μg·kg−1. The method is rapid, simple, sensitive and suitable for rapid determination and analysis of imidacloprid and its metabolites in P. clarkii tissues.

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