scholarly journals Preparation of Imazethapyr Surface Molecularly Imprinted Polymers for Its Selective Recognition of Imazethapyr in Soil Samples

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Yanqiang Zhou ◽  
Yinhui Yang ◽  
Meihua Ma ◽  
Zhian Sun ◽  
Shanshan Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Selective Extraction ◽  
Soil Samples ◽  
Specific Recognition ◽  
Transmission Electron ◽  
Novel Strategy

A novel strategy based on imazethapyr (IM) molecular-imprinting polymers (MIPs) grafted onto the surface of chloromethylation polystyrene resin via surface-initiated atom transfer radical polymerization (SI-ATRP) for specific recognition and sensitive determination of trace imazethapyr in soil samples was developed. The SI-ATRP was performed by using methanol-water (4 : 1, v/v) as the solvent, acrylamide as the functional monomer, trimethylolpropane trimethacrylate (TRIM) as the cross-linker, imazethapyr as the template, and CuBr/2,2′-bipyridine as the catalyst. The resulting MIPs were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Then, the binding selectivity, adsorption capacity, and reusability of the MIPs were evaluated. The results indicated that the prepared MIPs exhibited specific recognition and high selectivity for imazethapyr. The MIPs were further used as solid-phase extraction (SPE) materials coupled with high-performance liquid chromatography (HPLC) for selective extraction and detection of trace imazethapyr from soil samples. The results showed that good linearity was observed in the range of 0.10–5.00 μg/mL, with a correlation coefficient of 0.9995. The limit of detection (LOD) of this method was 15 ng/g, and the extraction recoveries of imazethapyr from real samples were in the range of 91.1–97.5%, which proved applicable for analysis of trace imazethapyr in soils. This work proposed a sensitive, rapid, and convenient approach for determination of trace imazethapyr in soil samples.

Preparation of yolk–shell structured Ag@Cu particles and their application in high performance electrochemical sensing of p-aminobenzoic acid

2019 ◽  
Vol 97 (2) ◽  
pp. 140-146
Author(s):  
Tian Gan ◽  
Zhikai Wang ◽  
Mengru Chen ◽  
Wanqiu Fu ◽  
Haibo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
High Catalytic Activity ◽  
Aminobenzoic Acid ◽  
Transmission Electron

In this work, the Ag@Cu particles with yolk–shell nanostructure was prepared by facile solvothermal method, which was modified on glassy carbon electrode (GCE) to fabricate electrochemical sensor for the convenient and fast determination of p-aminobenzoic acid (PABA). The surface morphology and electrochemical properties of the as-prepared Ag@Cu nanocomposite modified electrode were characterized by scanning electron microscopy, transmission electron microscopy, chronocoulometry, and electrochemical impedance spectroscopy. Further, the electrochemical sensing of PABA was performed on the Ag@Cu/GCE using cyclic voltammetry and differential pulse voltammetry techniques, showing high catalytic activity. Under the optimal conditions, the sensor exhibited a wide linear range, high sensitivity, and low detection limit of 0.315 μmol/L for PABA. The developed sensor was also successfully applied for PABA detection in anesthetic and cosmetics with satisfactory results.

Detection of trace amounts of abamectin used as an antiparasitic agent in fallow deer tissues

2009 ◽  
Vol 57 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Diana Žele ◽  
Silvestra Kobal ◽  
Gorazd Vengušt ◽  
Andrej Bidovec ◽  
Anton Vengušt ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Fallow Deer ◽  
Reversed Phase ◽  
Fat Tissue ◽  
Matrix Interference ◽  
Solid Phase Extraction Cartridge ◽  
Tissue Matrix

A sensitive and reliable method for the determination of trace amounts of abamectin in muscles, kidneys and fat tissue of fallow deer is presented. Abamectin was extracted from the tissues with acetonitrile and the extract was cleaned up on a C8 solid-phase extraction cartridge. Abamectin residue was derivatised with trifluoroacetic acid anhydride and 1-methylimidazole, and determined using reversed- phase high-performance liquid chromatography under isocratic conditions and fluorescence detection. The recoveries of the method were high and consistent, ranging from 78% to 90%. The limit of detection of the method was below 1 μg/kg when analysing muscle, kidney and fat tissue. Matrix-matched calibration was used in order to obtain accurate values and to avoid matrix interference.

scholarly journals Application of Packed-nanofibers Solid-phase Extraction for Determination of Rhodamine B in Sausage

2019 ◽  
Vol 8 (1) ◽  
pp. 17-21
Author(s):  
Lanlan Wei ◽  
Jianjun Deng ◽  
Tao Kang ◽  
Xuejun Kang
Keyword(s):  
Rhodamine B ◽  
High Performance ◽  
Orthophosphoric Acid ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Volume Ratio ◽  
Standard Curve ◽  
Relative Standard ◽  
Limit Of Quantitation

A method for the determination of Rhodamine B in sausage was developed and validated. After extraction of Rhodamine B with acetonitrile from foodstuffs, a novel electrospun polymer nanofibers packed micro-column was used for cleaning and concentrating of the analyte in the sample. High performance liquid chromatography with fluorescence detection (HPLC-Flu) was used for the determination of Rhodamine B in the sample. The mobile phase was composed of 3.0 g L-1 phosphate buffer and methanol (3:7, volume ratio), and the pH was adjusted to 7. 0 with orthophosphoric acid. The results showed that the standard curve was linear over the validated concentrations range of 2-500 ng g-1, and the limit of detection (LOD) and the limit of quantitation (LOQ) for Rhodamine B spiked samples was 0. 2 ng g-1 and 0. 7 ng g-1, respectively. The average recoveries of Rhodamine B were 90.4% -94.3% for sausage, and the relative standard deviation of the method was from 1.7% to 3.8%. This proposed method was applied to real sample, and there was no Rhodamine B found in sausage.

scholarly journals Development and validation of a SPE-UHPLC-fluorescence method for the analysis of ochratoxin-a in certain Turkish wines

2019 ◽  
Vol 38 (2) ◽  
pp. 161
Author(s):  
Elif Mine Oncu Kaya
Keyword(s):  
Ochratoxin A ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Internal Standard ◽  
Fluorescence Method ◽  
Limit Of Quantitation ◽  
Development And Validation

A sensitive Ultra-High Performance Liquid Chromatography (UHPLC)-fluorescence method was developed and validated for the determination of ochratoxin-A (OTA) in Turkish wine samples. Naphthalene was used as an internal standard in this study. OTA was separated on a C18 (3.0 mm × 100 mm × 1.8 µm) column and analyses were run under isocratic conditions, with a mobile phase consisting of water/acetonitrile/acetic acid (50:50:1, v/v/v). The flow rate and injection volume were 0.5 ml min−1 and 10 μl, respectively. The excitation and emission wavelengths were 330 nm and 460 nm for OTA, respectively, and 220 nm and 325 nm for internal standard, respectively. A solid-phase extraction (SPE) clean-up procedure on a C18 cartridge was used prior to the analysis of the wine samples by UHPLC. The developed method was validated with respect to linearity, precision, accuracy, limit of detection (LOD), limit of quantitation (LOQ), stability and robustness. The method presented good RSD (< 4 %) and recovery (102.6–105.2 %) values. The LOD and LOQ values were 0.01 ng ml–1 and 0.05 ng ml–1, respectively. All other parameters were acceptable. OTA amounts were found in the range of 2.72‒7.40 µg kg‒1 in the Turkish wine samples.

scholarly journals HPLC method validation and application for organic acid analysis in wine after solid-phase extraction

2016 ◽  
Vol 35 (2) ◽  
pp. 225 ◽  
Author(s):  
Violeta Ivanova-Petropulos ◽  
Krste Tašev ◽  
Marina Stefova
Keyword(s):  
Solid Phase Extraction ◽  
Organic Acids ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Hplc Method ◽  
Phase Extraction ◽  
Hplc Separation ◽  
Limit Of Quantification

<p>A solid-phase extraction method followed by reverse phase high-performance liquid chromatography (RP-HPLC) was optimized and validated for the quantitative determination of tartaric, malic, shikimic, lactic, citric and succinic acids in wine. Solid-phase extraction was carried out with C18 cartridges and extraction recoveries for all acids ranging from 98.3 to 103% were obtained. HPLC separation was performed with isocratic elution on a LiChrosorb RP-18 column (250 × 4.6 mm I.D., 5 µm) protected with the appropriate guard column. The mobile phase was a 5 mM solution of H<sub>3</sub>PO<sub>4</sub> with pH 2.1 at a flow rate of 1 ml/min. Detection of the organic acids was performed at 210 nm. The developed method was validated by checking its linearity, limit of detection (LOD), limit of quantification (LOQ), precision and recovery. The method was applied to the analysis of organic acids in Macedonian red and white wines.</p>

scholarly journals Construction of Sandwich-like Structured GO/Cu2O/GO Electrochemical Biosensor for Sensitive Detection of H2O2 Releasing from Living Cells

2020 ◽  
Author(s):  
Donghang Yin ◽  
Junyan Tang ◽  
Ruixue Mo ◽  
Fei Wang ◽  
Xiuzhi Jia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Indium Tin Oxide ◽  
High Performance ◽  
Limit Of Detection ◽  
A549 Cells ◽  
X Ray Diffraction ◽  
Long Term Stability ◽  
Transmission Electron ◽  
Ito Glass

Abstract A well-designed sandwich-like structure based on Cu2O nanocubes sandwiched between graphene oxide (GO) buffer layer was fabricated on indium tin oxide (ITO)/glass substrate via drop-casting method. The sandwich-like morphologies, GO/Cu2O/GO/ITO structures, were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) measurements. Electrochemical studies demonstrated the fact that GO/Cu2O/GO/ITO electrode revealed the superior electro-catalytic activity and electrical conductivity as a result of the introduction of graphene oxide and formation of sandwich-like structures, which effectively improved the electrical performances of Cu2O-based sandwich structure in H2O2 detection. The proposed sandwich-like GO/Cu2O/GO/ITO sensor was experimentally optimized and displayed a widespread linear response in the range from 0.25 μM to 20 mM with a low limit of detection (LOD) of 0.2 μM (S/N=3) in H2O2 sensing. Besides achieving acceptable selectivity, excellent reproducibility, and long-term stability of sandwich-like lamellar structures, GO/Cu2O/GO/ITO sensor exhibited high performance in detecting H2O2 released from A549 cells. Therefore, the novel sandwich-like GO/Cu2O/GO/ITO sensor provides an economical, potent and high-throughput platform for detecting various species involving H2O2-generation reactions for biomedical applications.

scholarly journals Quantitative Analysis of Three Chiral Pesticide Enantiomers by High-Performance Column Liquid Chromatography

2008 ◽  
Vol 91 (5) ◽  
pp. 1007-1012 ◽  
Author(s):  
Peng Wang ◽  
Donghui Liu ◽  
Xu Gu ◽  
Shuren Jiang ◽  
Zhiqiang Zhou
Keyword(s):  
Quantitative Analysis ◽  
Quantitative Determination ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Optical Purity ◽  
High Performance Liquid Chromatographic ◽  
Precision Data ◽  
Chiral Pesticides

Abstract Methods for the enantiomeric quantitative determination of 3 chiral pesticides, paclobutrazol, myclobutanil, and uniconazole, and their residues in soil and water are reported. An effective chiral high-performance liquid chromatographic (HPLC)-UV method using an amylose-tris(3,5-dimethylphenylcarbamate; AD) column was developed for resolving the enantiomers and quantitative determination. The enantiomers were identified by a circular dichroism detector. Validation involved complete resolution of each of the 2 enantiomers, plus determination of linearity, precision, and limit of detection (LOD). The pesticide enantiomers were isolated by solvent extraction from soil and C18 solid-phase extraction from water. The 2 enantiomers of the 3 pesticides could be completely separated on the AD column using n-hexane isopropanol mobile phase. The linearity and precision results indicated that the method was reliable for the quantitative analysis of the enantiomers. LODs were 0.025, 0.05, and 0.05 mg/kg for each enantiomer of paclobutrazol, myclobutanil, and uniconazole, respectively. Recovery and precision data showed that the pretreatment procedures were satisfactory for enantiomer extraction and cleanup. This method can be used for optical purity determination of technical material and analysis of environmental residues.

Extraction and Determination of Triclocarban in Aquatic Plants by Homogenate Extraction Combined with HPLC-ESI-MS/MS

2013 ◽  
Vol 864-867 ◽  
pp. 343-346
Author(s):  
Hong Hao Miao ◽  
Xi Kui Wang ◽  
Wei Lin Guo
Keyword(s):  
Aquatic Plants ◽  
High Performance ◽  
Aquatic Plant ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Water Environment ◽  
Correlation Coefficients ◽  
Plant Samples ◽  
Homogenate Extraction

A specific, sensitive, and reliable analytical method involving homogenate extraction, solid phase extraction (SPE), and detection by high-performance liquid phase chromatography electrospray tandem mass spectrometry was developed in this study for the determination of triclocarban (TCC) in aquatic plants. Key factors that could affect the extraction, including the extraction solvent and its volume, the length of time of homogenate extraction, were examined and optimised. Under optimum conditions, the linearity of the method ranged from 0.2 ng/g to 200 ng/g, with correlation coefficients (r2) >0.999. The limit of detection was 0.05 ng/g, based on the ratio of the chromatographic signal to baseline noise (S/N = 3). Spiked recoveries of TCC in real aquatic plant samples ranged from 91.8% to 106.1%. The proposed method was successfully applied to analyse TCC in aquatic plant samples collected from a natural water environment.

Molecularly imprinted polymers for the selective determination of trace bisphenol A in river water by electrochemiluminescence

2013 ◽  
Vol 91 (8) ◽  
pp. 656-661 ◽  
Author(s):  
Xiaohua Jiang ◽  
Wengjie Ding ◽  
Chonglin Luan
Keyword(s):  
Bisphenol A ◽  
River Water ◽  
Limit Of Detection ◽  
Solid Phase ◽  
High Sensitivity ◽  
Selective Extraction ◽  
Molecularly Imprinted ◽  
Selective Determination ◽  
Extraction And Purification

The detection of bisphenol A (BPA) is very important for public health and environmental monitoring. In this work, BPA was found to be able to significantly quench the electrochemiluminescence (ECL) of the Ru(bpy)32+/2-(dibutylamino)ethanol (DBAE) system. Molecularly imprinted polymer was synthesized as solid-phase extraction sorbents, which were used for the selective extraction and purification of BPA. Under optimal conditions, the inhibited ECL intensity versus the logarithm of the concentration of BPA was in good linear relationship over a concentration range from 2.2 × 10−10 to 1.1 × 10−7 mol/L. The limit of detection was 4.5 × 10−11 mol/L (S/N = 3). The developed method was successfully applied for determination of BPA in river water with high sensitivity and reliability. Further, a possible mechanism for the quenching effects of the Ru(bpy)32+/DBAE system by BPA was also proposed.

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