Determination of BTEX Compounds in Contaminated Water Using the Novel Vacuum-Assisted-Total Vaporization SPME Method and GO-APTES Fiber

2021 ◽  
Author(s):  
Mohammad Beiranvand
Keyword(s):  
Solid Phase ◽  
Human Health Risk ◽  
Contaminated Water ◽  
Aqueous Sample ◽  
Experimental Conditions ◽  
Relative Standard ◽  
Wide Range ◽  
Headspace Spme ◽  
Total Vaporization

Abstract A novel and reliable microextraction technique was used for the fast determination of benzene, toluene, ethylbenzene and xylenes (BTEX) from contaminated water without any extra steps for the preparation or extraction of the aqueous sample. Vacuum-assisted-total vaporization-solid-phase microextraction (SPME) eliminated one of the partitioning steps in conventional headspace SPME and caused an increase in the sensitivity and speed of the method. A home-made graphene oxide/3-aminopropyl-triethoxysilane nanocomposite SPME fiber was synthesized and used as the extraction phase for efficient extraction. Several crucial parameters were optimized, such as the vaporization time and temperature, extraction time and desorption conditions. At the optimum experimental conditions, a linear wide range calibration curve over a wide range of 1–5,000 ng mL−1 and a relative standard deviation (n = 6) of 6.6–7.3% were obtained. The result of the determination of BTEX as a human health risk from real samples, using the proposed method, revealed an acceptable agreement with a valid method.

scholarly journals Determination of Residual Nonsteroidal Anti-Inflammatory Drugs in Aqueous Sample Using Magnetic Nanoparticles Modified with Cetyltrimethylammonium Bromide by High Performance Liquid Chromatography

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Malihe Khoeini Sharifabadi ◽  
Mohammad Saber-Tehrani ◽  
Syed Waqif Husain ◽  
Ali Mehdinia ◽  
Parviz Aberoomand-Azar
Keyword(s):  
Magnetic Nanoparticles ◽  
Cetyltrimethylammonium Bromide ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Aqueous Sample ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen) using Fe3O4magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface ofMNPswas modified with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02) acetonitrile (65 : 35 v/v) as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD%) of the method was investigated at three concentrations (25, 50, and 200 ng/mL) and was in the range of 3.98–9.83%(n=6)for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity(R2>0.99)and the limit of detection(LODs)ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.

Fluoroimmunoassay Based on FITC-Labeled Antibody for the Determination of Estradiol

2014 ◽  
Vol 960-961 ◽  
pp. 3-6
Author(s):  
Long Jun Wang ◽  
Wei Li Xue ◽  
Ling Yun Du
Keyword(s):  
Human Urine ◽  
High Performance ◽  
Solid Phase ◽  
High Sensitivity ◽  
Good Precision ◽  
Experimental Conditions ◽  
Time Saving ◽  
Relevant Variable ◽  
Relative Standard

A new fluorescence immunoassay with high sensitivity, time-saving, good precision and reliablility was proposed for the determination of estradiol (E2) in human urine. The complex of FITC-labeled anti-E2antibody was produced and regarded as a probe in this system. Ninety-six microplate was coated with ovalbumin conjugated E2antigen as solid phase for the immunoassay. The method parameters affecting the determination, such as the concentration of immunoreagents, pH, and other relevant variable conditions upon the immunoassay were studied and optimized systematically. Under the optimal experimental conditions, it was found that the proposed method exhibited high performance with the detection limit of 9.2 pg/mL, and the linear range of determination of 0.01-1000 ng/mL. The recoveries were 93.58-105.82% with the relative standard deviations (RSD) 5.52-7.09%. The proposed method has been used for the determination of E2in human urine with satisfactory results, and may be expected to find wide application in other environmental samples.

scholarly journals Inter-laboratory validation of automated SPME-GC/MS for determination of pesticides in surface and ground water samples: sensitive and green alternative to liquid–liquid extraction

2016 ◽  
Vol 51 (4) ◽  
pp. 331-343 ◽  
Author(s):  
Angel Rodriguez-Lafuente ◽  
Hamed Piri-Moghadam ◽  
Heather L. Lord ◽  
Terry Obal ◽  
Janusz Pawliszyn
Keyword(s):  
Ground Water ◽  
Water Samples ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Reference Laboratory ◽  
Test Protocol ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Wide Range

An automated solid-phase microextraction gas chromatography/mass spectometry (SPME-GC/MS) method was developed for the determination of semi-volatile pesticides from several classes with a wide range of polarities in an environmental matrix, and validated according to the rigorous standards of a large commercial laboratory reporting data requiring regulatory acceptance with the purpose of being used as a standard test protocol. The target analytes showed a detection limit of 0.05–1 μg L−1, good calibration linearity (R2 > 0.99) with a wide linear range of 0.05–20 μg L−1, and accuracy in the range of 80–110 at three levels of calibration with relative standard deviation below 7% by commercial polydimethylsiloxane/divinylbenzene (PDMS/DVB) SPME fiber. An extensive study between SPME and liquid–liquid extraction as a reference US EPA method was performed from several analytical aspects including sensitivity, accuracy, repeatability, and greenness. The SPME method was validated through split blind analyses of 16 fortified surface and ground water samples within 4 months at Maxxam Analytics, the reference laboratory, and the University of Waterloo. Both methods were shown to be very accurate, with the highest frequency of results falling in the 70–130% accuracy range. The SPME method was shown to be more sensitive than the LLE, while requiring a lower volume of sample.

scholarly journals Determination of Bisphenol Ain Water by Isotope Dilution Headspace Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry Without Derivatization

2008 ◽  
Vol 91 (3) ◽  
pp. 622-629 ◽  
Author(s):  
Xu-Liang Cao ◽  
Jeannette Corriveau
Keyword(s):  
Detection Limit ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Method Detection Limit ◽  
Spme Fiber ◽  
Relative Standard ◽  
Headspace Spme ◽  
Epoxy Resin Adhesive

Abstract The original solid-phase microextraction (SPME) fibers use an epoxy resin adhesive that releases bisphenol A (BPA) during thermal desorption of the fiber. This adversely affects the method detection limit and accuracy when these products are used for the determination of BPA. In this work, 5 new metal alloy SPME fibers that do not use epoxy resins were compared for the extraction of BPA in water. The performance of the optimum SPME fiber with 60 m carbowax-polyethylene glycol coating for the headspace SPME of BPA in water was investigated systematically under different extraction conditions. Salt was found to increase the partitioning of BPA from water into the headspace until saturation was reached. Partitioning of BPA from water into the headspace also increased at higher extraction temperatures, as did longer extraction times. However, extraction of BPA from water onto the SPME fiber was not improved for solutions adjusted to pH 2 compared to the unadjusted neutral solutions. The new BPA method showed good linearity over the concentration range of 2.5 to 40 g/L [correlation coefficient (r2) = 0.995] .The method detection limit for BPA was 0.5 g/L, while the instrument detection limit was as low as 0.05 g/L. Good repeatability was observed for BPA at levels of 5 and 20 g/L with relative standard deviation values <10. The automated headspace SPME method developed in this work was used to investigate migration of BPA from polycarbonate bottles into water, and levels of BPA in water ranged from 1.7 to 4.1 g/L.

scholarly journals Recent Developments in the Determination of Biomarkers of Tobacco Smoke Exposure in Biological Specimens: A Review

2021 ◽  
Vol 18 (4) ◽  
pp. 1768
Author(s):  
Hernâni Marques ◽  
Pedro Cruz-Vicente ◽  
Tiago Rosado ◽  
Mário Barroso ◽  
Luís A. Passarinha ◽  
...  
Keyword(s):  
Tobacco Smoke ◽  
Solid Phase ◽  
Smoke Exposure ◽  
Tobacco Smoke Exposure ◽  
World Health ◽  
Second Hand Smoke ◽  
Tobacco Exposure ◽  
Wide Range ◽  
Recent Developments

Environmental tobacco smoke exposure (ETS) and smoking have been described as the most prevalent factors in the development of certain diseases worldwide. According to the World Health Organization, more than 8 million people die every year due to exposure to tobacco, around 7 million due to direct ETS and the remaining due to exposure to second-hand smoke. Both active and second-hand exposure can be measured and controlled using specific biomarkers of tobacco and its derivatives, allowing the development of more efficient public health policies. Exposure to these compounds can be measured using different methods (involving for instance liquid- or gas-chromatographic procedures) in a wide range of biological specimens to estimate the type and degree of tobacco exposure. In recent years, a lot of research has been carried out using different extraction methods and different analytical equipment; this way, liquid–liquid extraction, solid-phase extraction or even miniaturized procedures have been used, followed by chromatographic analysis coupled mainly to mass spectrometric detection. Through this type of methodologies, second-hand smokers can be distinguished from active smokers, and this is also valid for e-cigarettes and vapers, among others, using their specific biomarkers. This review will focus on recent developments in the determination of tobacco smoke biomarkers, including nicotine and other tobacco alkaloids, specific nitrosamines, polycyclic aromatic hydrocarbons, etc. The methods for their detection will be discussed in detail, as well as the potential use of threshold values to distinguish between types of exposure.

scholarly journals Rapid Determination of Ethylene Oxide and 75 VOCs in Ambient Air with Canister Sampling and Associated Growth Issues

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 35
Author(s):  
Jason Hoisington ◽  
Jason S. Herrington
Keyword(s):  
Ethylene Oxide ◽  
Rapid Determination ◽  
Complex Mixture ◽  
Ambient Air ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Accuracy ◽  
Relative Standard ◽  
Wide Range ◽  
Us Epa

A canister-based sampling method along with preconcentrator-Gas chromatography-Mass Spectrometry (GC-MS) analysis was applied to ethylene oxide (EtO or EO) and 75 other volatile organic compounds (VOCs) in ambient air. Ambient air can contain a large variety of VOCs, and thorough analysis requires non-discriminatory sampling and a chromatographic method capable of resolving a complex mixture. Canister collection of whole air samples allows for the collection of a wide range of volatile compounds, while the simultaneous analysis of ethylene oxide and other VOCs allows for faster throughput than separate methods. The method presented is based on US EPA Method TO-15A and allows for the detection of EtO from 18 to 2500 pptv. The method has an average accuracy of 104% and precision of 13% relative standard deviation (RSD), with an instrument run time of 32 min. In addition, a link between canister cleanliness and ethylene oxide growth is observed, and potential mechanisms and cleaning strategies are addressed.

Residue Analysis of Organophosphorus and Organochlorine Pesticides in Fatty Matrices by Gas Chromatography Coupled with Electron-Capture Detection

2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Simple Procedure ◽  
Linear Regression Analysis ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Repeatability And Reproducibility

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water 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.

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