A Novel Electrochemiluminescence Sensor for Sensitive Determination of Carbaryl Based on Solid Phase Microextraction at NH2–Graphene–Nafion Modified Electrode

2015 ◽  
Vol 68 (5) ◽  
pp. 793 ◽  
Author(s):  
Sui Wang ◽  
Shasha Lv ◽  
Wenwen Wu ◽  
Zhiyong Guo
Keyword(s):  
Solid Phase Microextraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Initial Response ◽  
X Ray Diffraction ◽  
Relative Standard ◽  
Sensitive Determination ◽  
Response Current

Sensitive electrochemiluminescence (ECL) detection and solid phase microextraction (SPME) using a NH2–graphene–Nafion modified glassy carbon electrode was developed for carbaryl. The NH2–graphene was synthesised and characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The main parameters that affect the extraction efficiencies, such as the buffer and sample pH, and extraction time were investigated and optimised. The introduction of NH2–graphene into Nafion improves the conductivity of the film because of its electrical conductivity. The electrode enables the determination of carbaryl in the range from 5 × 10–4 to 10 μg mL–1, and the limit of detection was 2 × 10–4 μg mL–1 at a signal-to-noise ratio of 3. The ECL intensity retained 97 % of its initial response current after storage for 10 days, indicating a good storage stability of the sensor. The relative standard deviations (RSDs) of intra-assay and inter-assay were found to be 3.5 and 5.3 %, respectively, indicating an acceptable reproducibility. Furthermore, the ECL sensor was successfully applied to the selective and sensitive quantitative determination of carbaryl in river samples, the recoveries of carbaryl ranged from 99.0 to 108.0 %, and the RSDs were less than 5.0 %, which shows good reproducibility and high precision of analysis.

Headspace Solid Phase Microextraction Procedure for the Detection of Polychlorinated Biphenyls in Seawater Sample

2013 ◽  
Vol 316-317 ◽  
pp. 383-386
Author(s):  
Xian Yin Ping ◽  
Yun Long Wang
Keyword(s):  
Polychlorinated Biphenyls ◽  
Film Thickness ◽  
Solid Phase Microextraction ◽  
Extraction Efficiency ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Headspace Solid Phase Microextraction ◽  
Relative Standard ◽  
Seawater Samples

Headspace solid phase microextraction combined with gas chromatography (HS-SPME–GC) method has been studied for determination of 7 polychlorinated biphenyls (PCBs) in seawater samples. To perform the HS-SPME polydimethylsiloxane (PDMS) (7, 30 and 100 µm film thickness) fibers were compared on the basis of their absorption capacities for the selected compounds, and PDMS 100 µm film thickness was selected. The influence of various parameters on PCBs extraction efficiency by HS-SPME was studied using GC-electron capture detector (ECD) compared with solid phase. The performance of proposed HS-SPME–GC methodology with respect to linearity, reproducibility and limit of detection (LOD) was evaluated by water spiked with target compounds. The linear range of most compounds was found to be between 0.1 and 100 µgL−1 and the limits of detection were between 15.2 and 63.8 ngL−1. The reproducibility of the method (n = 6), expressed as relative standard deviation (RSD), was between 4 and 10%. Finally, developed procedure was applied to determine selected PCBs in seawater samples.

A Simple Vortex-Assisted Magnetic Dispersive Solid Phase Microextraction System for Preconcentration and Separation of Triazine Herbicides from Environmental Water and Vegetable Samples Using Fe3O4@MIL-100(Fe) Sorbent

2018 ◽  
Vol 101 (5) ◽  
pp. 1639-1646 ◽  
Author(s):  
Atefe Nasrollahpour ◽  
Seyyed Ershad Moradi
Keyword(s):  
Solid Phase Microextraction ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Correlation Coefficients ◽  
Environmental Water ◽  
Triazine Herbicides ◽  
Vegetable Samples ◽  
Relative Standard

Abstract A vortex-assisted magnetic dispersive solid phase microextraction coupled with high-performance liquid chromatography has been developed for the extraction and determination of triazine herbicides by using magnetic metal organic frameworks [Fe3O4@MIL-100(Fe)] in environmental water and vegetable samples. The Fe3O4@MIL-100(Fe) composite has been characterized by using X-ray diffraction spectroscopy, tunneling electron microscopy, thermogravimetric measurement, and Brunauer-Emmett-Teller analysis. The method is based on the sorption of triazine herbicides on Fe3O4@MIL-100(Fe) because of the complex formation between iron oxide nanoparticles and triazine herbicides beside π-π interactions between organic parts of Fe3O4@MIL-100(Fe) and triazine herbicides. The experimental parameters for the preconcentration of triazine herbicides, such as the type and volume of the eluent, pH, time of the sorption and desorption, and the amount of the sorbent, were optimized. Under the optimized conditions, the method was linear over the concentration range of 0.0061 to 70 ng/mL for each triazine herbicide, and the correlation coefficients ranged from 0.9988 to 0.9997. The limit of detection of the method at a signal-to-noise ratio of 3 was 2.0 to 5.3 ng/mL. The relative standard deviations for inter- and intraday assays were in the range of 5.8 to 10.2% and 3.8 to 6.3%, respectively.

Development of a solid-phase extraction – spectrofluorimetric method for trace glutathione determination

2011 ◽  
Vol 89 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Ke-Jing Huang ◽  
Cong-Hui Han ◽  
Ying-Ying Wu ◽  
Chao-Qun Han ◽  
De-Jun Niu ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Calibration Graph ◽  
Extraction Column ◽  
Phase Extraction ◽  
Selective Reaction ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A simple and efficient solid-phase extraction – spectrofluorimetric method has been developed to determine glutathione (GSH). Fluorescent probe N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl)iodoacetamide (BODIPY Fl-C1-IA) was used as the derivatization reagent. The procedure was based on a BODIPY Fl-C1-IA selective reaction with GSH to form the highly fluorescent product BODIPY Fl-C1-IA–GSH, using a solid-phase extraction column and spectrofluorimetric determination. The variables affecting analytical performance were studied and optimized. The calibration graph using the preconcentration system for GSH was linear over the range of 1–200 nmol/L with a limit of detection of 0.05 nmol/L (signal-to-noise ratio = 3). The relative standard deviation for six replicate determinations of GSH at the 100 nmol/L concentration level was 3.9%. The method was applied to water samples and average recoveries between 87.5% and 111.5% were obtained for spiked samples.

scholarly journals Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Limit Of Quantification ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Primary Secondary Amine

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.

scholarly journals Determination of multi-class herbicides in soil by liquid-solid extraction coupled with headspace solid phase microextraction method

2016 ◽  
Vol 81 (8) ◽  
pp. 923-934 ◽  
Author(s):  
Rada Djurovic-Pejcev ◽  
Tijana Djordjevic ◽  
Vojislava Bursic
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Soil Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Optimum Number ◽  
Polydimethyl Siloxane ◽  
Headspace Solid Phase Microextraction ◽  
Relative Standard ◽  
Detection And Quantification

A method is described for simultaneous determination of five herbicides (metribuzin, acetochlor, clomazone, oxyfluorfen and dimethenamid) belonging to different pesticides groups in soil samples. Developed headspace solid phase microextraction method (HS-SPME) in combination with liquid-solid sample preparation (LS) was optimized and applied in the analysis of some agricultural samples. Optimization of microextraction conditions, such as temperature, extraction time and sodium chloride (NaCl) content was perfor-med using 100 ?m polydimethyl-siloxane (PDMS) fiber. The extraction effi-ciencies of methanol, methanol:acetone=1:1 and methanol:acetone:hexane= =2:2:1 and the optimum number of extraction steps during the sample prepa-ration, were tested, as well. Gas chromatography-mass spectrometry (GC-MS) was used for detection and quantification, obtaining relative standard deviation (RSD) below 13%, and recovery values higher than 83% for multiple analyses of soil samples fortified at 30 ?g kg-1 of each herbicide. Limits of detection (LOD) were less than 1.2 ?g kg-1 for all the studied herbicides.

scholarly journals Simultaneous Determination of Some Phenothiazine Derivatives in Human Blood by Headspace Solid-Phase Microextraction and Gas Chromatography with Nitrogen-Phosphorus Detection

2008 ◽  
Vol 91 (6) ◽  
pp. 1354-1362 ◽  
Author(s):  
Natsuko Shinmen ◽  
Xiao-Pen Lee ◽  
Takeshi Kumazawa ◽  
Chika Hasegawa ◽  
Yasuhiro Ishiwata ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Whole Blood ◽  
Solid Phase Microextraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Regression Equations ◽  
Phenothiazine Derivatives ◽  
Headspace Solid Phase Microextraction ◽  
Coefficients Of Variation

Abstract Chlorpromazine, levomepromazine, promazine, triflupromazine, and trimeprazine were simultaneously determined in human whole blood and plasma by combining headspace solid-phase microextraction and gas chromatography with nitrogenphosphorus detection. Extraction efficiency for the phenothiazine derivatives was 0.0130.117 for both sample types. Regression equations were linear [correlation coefficient (r) 0.99510.9999] within the range 2.5200 ng/0.5 mL for triflupromazine and trimeprazine, and 6.3200 ng/0.5 mL for chlorpromazine, levomepromazine, and promazine. The limit of detection for each compound was 0.23.9 ng/0.5 mL whole blood and plasma. Intraday and interday coefficients of variation for all phenothiazines in both human samples were commonly <15 and 20, respectively. We also report the determination of levomepromazine in human plasma after oral administration.

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