PubAg

Main content area

You searched for: Subject "ionic strength" Remove constraint Subject: "ionic strength" Journal Journal of chromatography Remove constraint Journal: Journal of chromatography Subject gas chromatography-mass spectrometry Remove constraint Subject: gas chromatography-mass spectrometry Subject detection limit Remove constraint Subject: detection limit
Start Over

Search

24  Search Results

« Previous | 1 - 20 of 24 |
Number of results to display per page

Search Results

1. Sol–gel based metal-organic framework zeolite imidazolate framework-8 fibers for solid-phase microextraction of nitro polycyclic aromatic hydrocarbons and polycyclic aromatic hydrocarbons in water samples

Author:
Kong, Jijie; Zhu, Fengxi; Huang, Wen; He, Huan; Hu, Jiapeng; Sun, Cheng; Xian, Qiming; Yang, Shaogui
Source:
Journal of chromatography 2019 v.1603 pp. 92-101
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; coatings; coordination compounds; desorption; detection limit; environmental assessment; gas chromatography-mass spectrometry; hydrophobicity; mixing; pH; polycyclic aromatic hydrocarbons; solid phase microextraction; stainless steel; standard deviation; tandem mass spectrometry; temperature; zeolites;     Show all 17 Subjects
Abstract:
... In this study, three kinds of Zeolite imidazolate framework-8 (ZIF-8), synthesized by solvothermal, stirring and ball-milling method, were fabricated on the stainless steel wire via sol-gel technique. These fibers were used as solid phase microextraction (SPME) coating materials and applied for analyzing 16 polycyclic aromatic hydrocarbons (PAHs) and 11 nitro polycyclic aromatic hydrocarbons (NPAH ...
DOI:
10.1016/j.chroma.2019.06.063

2. Expanding the application of stir bar sorptive-dispersive microextraction approach to solid matrices: Determination of ultraviolet filters in coastal sand samples

Author:
Benedé, Juan L.; Chisvert, Alberto; Moyano, Carla; Giokas, Dimosthenis L.; Salvador, Amparo
Source:
Journal of chromatography 2018 v.1564 pp. 25-33
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; UV filters; coatings; desorption; detection limit; ethanol; gas chromatography-mass spectrometry; hydrophobicity; magnetism; microextraction; mixing; nanoparticles; pH; recreation; sand; sorbents; statistical analysis;     Show all 17 Subjects
Abstract:
... This work describes a new method for the determination of organic compounds in solid samples based on the equilibrium desorption of the analytes in an aqueous phase followed by stir bar sorptive-dispersive microextraction (SBSDME). Sand samples, contaminated with UV filters due to bathing and recreational activities, were dispersed in an aqueous medium by using a coated stir bar with CoFe2O4@oleic ...
DOI:
10.1016/j.chroma.2018.06.003

3. Magnetic carbon nanotube composite for the preconcentration of parabens from water and urine samples using dispersive solid phase extraction

Author:
Pastor-Belda, Marta; Marín-Soler, Lidia; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel
Source:
Journal of chromatography 2018 v.1564 pp. 102-109
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; acetylation; adsorption; carbon nanotubes; desorption; detection limit; gas chromatography-mass spectrometry; magnetic materials; magnetism; solid phase extraction; solvents; urine; wastewater treatment;     Show all 13 Subjects
Abstract:
... This study describes the use of a magnetic multi-walled carbon nanotube composite for the preconcentration of nine parabens (methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, phenyl and benzylparaben) from water and urine samples after in situ acetylation. The enriched extracts were obtained by dispersive magnetic solid phase extraction (DMSPE) and analysed by gas chromatography with mass ...
DOI:
10.1016/j.chroma.2018.06.025

4. Purification and enrichment of polycyclic aromatic hydrocarbons in environmental water samples by column clean-up coupled with continuous flow single drop microextraction A

Author:
Li, Yue; Zhang, Lening; Wu, Lijie; Sun, Shuang; Shan, Hongyan; Wang, Ziming
Source:
Journal of chromatography 2018
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; detection limit; gas chromatography-mass spectrometry; microextraction; pH; packaging materials; polycyclic aromatic hydrocarbons; solvents; statistical analysis; temperature;     Show all 10 Subjects
Abstract:
... A novel method for the determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in environmental water samples was developed using column clean-up (CCU) coupled with continuous flow single drop microextraction (CF-SDME) prior to the determination by gas chromatography-mass spectrometry (GC–MS). In this method, purification, extraction and enrichment were carried out in a single step, which ...
DOI:
10.1016/j.chroma.2018.07.013

5. Core–shell electrospun polybutylene terephthalate/polypyrrole hollow nanofibers for micro-solid phase extraction

Author:
Bagheri, Habib; Rezvani, Omid; Banihashemi, Solmaz
Source:
Journal of chromatography 2016 v.1434 pp. 19-28
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; desorption; detection limit; gas chromatography-mass spectrometry; moieties; nanofibers; pH; pyrroles; regression analysis; scanning electron microscopy; solvents; sorbents; temperature; triazine herbicides; wheat;     Show all 15 Subjects
Abstract:
... In the present work, a new micro-solid phase extraction (μ-SPE) sorbent as an extracting medium based on core–shell nanofibers was synthesized by electrospinning. The core–shell nanofibers of polyvinylpyrrolidone-Polybutylene terephthalate/polypyrrole (PVP-PBT/PPy) were electrospun and subsequently, modified hollow nanofibers were prepared by removing the central PVP moiety. Moreover, conventional ...
DOI:
10.1016/j.chroma.2015.12.082

6. Polydopamine decorated 3D nickel foam for extraction of sixteen polycyclic aromatic hydrocarbons A

Author:
Cai, Ying; Yan, Zhihong; Yang, Ming; Huang, Xiaoying; Min, Weiping; Wang, Lijia; Cai, Qingyun
Source:
Journal of chromatography 2016
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; X-ray photoelectron spectroscopy; adsorption; desorption; detection limit; energy; energy-dispersive X-ray analysis; foams; gas chromatography-mass spectrometry; nickel; pH; polycyclic aromatic hydrocarbons; river water; scanning electron microscopy; solid phase extraction; solvents; statistical analysis; wastewater;     Show all 18 Subjects
Abstract:
... In this work, polydopamine coated 3D nickel foam (NF-PDA) was prepared and applied as sorbent for the solid phase extraction (SPE) of 16 polycyclic aromatic hydrocarbons (PAHs) from water samples. NF-PDA were synthesized by situ oxidative self-polymerization procedure and characterized by using the techniques of scanning electron microscopy (SEM), energy dispersive spectrum analysis (EDS) and X-ra ...
DOI:
10.1016/j.chroma.2016.11.030

7. Graphene oxide-based dispersive solid-phase extraction combined with in situ derivatization and gas chromatography–mass spectrometry for the determination of acidic pharmaceuticals in water A

Author:
Naing, Nyi Nyi; Li, Sam Fong Yau; Lee, Hian Kee
Source:
Journal of chromatography 2015 v.1426 pp. 69-76
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; derivatization; desorption; detection limit; diclofenac; gas chromatography-mass spectrometry; gemfibrozil; graphene; graphene oxide; ibuprofen; ketoprofen; models; pH; quaternary ammonium compounds; solid phase extraction; solvents; sorbents; statistical analysis;     Show all 18 Subjects
Abstract:
... A fast and low-cost sample preparation method of graphene based dispersive solid-phase extraction combined with gas chromatography–mass spectrometric (GC–MS) analysis, was developed. The procedure involves an initial extraction with water-immiscible organic solvent, followed by a rapid clean-up using amine functionalized reduced graphene oxide as sorbent. Simple and fast one-step in situ derivatiz ...
DOI:
10.1016/j.chroma.2015.11.070

8. Roles of inorganic oxide nanoparticles on extraction efficiency of electrospun polyethylene terephthalate nanocomposite as an unbreakable fiber coating A

Author:
Bagheri, Habib; Roostaie, Ali
Source:
Journal of chromatography 2015 v.1375 pp. 8-16
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; BTEX (benzene, toluene, ethylbenzene, xylene); benzene; coatings; desorption; detection limit; ethylbenzene; gas chromatography-mass spectrometry; headspace analysis; iron oxides; models; nanocomposites; nanofibers; nanoparticles; nickel oxide; polyethylene; polyethylene terephthalates; scanning electron microscopy; silica; solid phase microextraction; stainless steel; statistical analysis; tap water; temperature; toluene; volatile organic compounds; xylene;     Show all 27 Subjects
Abstract:
... In the present work, the roles of inorganic oxide nanoparticles on the extraction efficiency of polyethylene terephthalate-based nanocomposites were extensively studied. Four fiber coatings based on polyethylene terephthalate nanocomposites containing different types of nanoparticles along with a pristine polyethylene terephthalate polymer were conveniently electrospun on stainless steel wires. Th ...
DOI:
10.1016/j.chroma.2014.11.059

9. Trace analysis of endocrine disrupting compounds in environmental water samples by use of solid-phase extraction and gas chromatography with mass spectrometry detection A

Author:
Azzouz, Abdelmonaim; Ballesteros, Evaristo
Source:
Journal of chromatography 2014 v.1360 pp. 248-257
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; acetonitrile; alkylphenols; bisphenol A; derivatization; detection limit; drinking water; endocrine-disrupting chemicals; gas chromatography-mass spectrometry; groundwater; pH; rivers; silica gel; solid phase extraction; sorbents; statistical analysis; surface water; swimming pools; triclosan; wastewater;     Show all 20 Subjects
Abstract:
... A novel analytical method using a continuous solid-phase extraction system in combination with gas chromatography–mass spectrometry for the simultaneous separation and determination of endocrine disrupting compounds (EDCs) is reported. The method was applied to major EDCs of various types including parabens, alkylphenols, phenylphenols, bisphenol A and triclosan in water. Samples were preconcentra ...
DOI:
10.1016/j.chroma.2014.07.059

10. Electrospun modified silica-polyamide nanocomposite as a novel fiber coating A

Author:
Bagheri, Habib; Roostaie, Ali
Source:
Journal of chromatography 2014 v.1324 pp. 11-20
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; chlorobenzene; coatings; desorption; detection limit; gas chromatography-mass spectrometry; headspace analysis; models; nanocomposites; nanofibers; nanoparticles; polymers; scanning electron microscopy; silica; solid phase microextraction; stainless steel; temperature;     Show all 17 Subjects
Abstract:
... In the present work, a new solid phase microextraction (SPME) fiber coating based on modified silica-polyamide (PA) nanocomposite was electrospun on a stainless steel wire. Four modified silica-PA nanocomposites together with PA were fabricated by dispersing several typical modified silica nanoparticles in PA polymer solution prior to electrospinning. The surface characteristic of PA nanofibers an ...
DOI:
10.1016/j.chroma.2013.11.024

11. Simultaneous derivatization and ultrasound-assisted dispersive liquid–liquid microextraction of chloropropanols in soy milk and other aqueous matrices combined with gas-chromatography–mass spectrometry

Author:
Carro, A.M.; González, P.; Lorenzo, R.A.
Source:
Journal of chromatography 2013 v.1319 pp. 35-45
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; acetonitrile; beverages; chloroform; cost effectiveness; derivatization; detection limit; experimental design; food safety; fruit juices; gas chromatography-mass spectrometry; liquid-phase microextraction; milk; pH; solvents; soymilk; temperature; wastewater treatment;     Show all 18 Subjects
Abstract:
... A novel approach involving ultrasound-assisted dispersive liquid–liquid microextraction (UA-DLLME) and derivatization combined with gas chromatography–mass spectrometry was developed for the determination of chloropropanols in water and beverages. UA-DLLME was optimized as less solvent-consuming and cost-effective extraction method for water, fruit juice, milk and soy milk samples. The effect of p ...
DOI:
10.1016/j.chroma.2013.10.055

12. Speciation of common volatile halogenated disinfection by-products in tap water under different oxidising agents

Author:
Montesinos, Isabel; Gallego, Mercedes
Source:
Journal of chromatography 2013 v.1310 pp. 113-120
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; byproducts; chlorine; detection limit; disinfection; gas chromatography-mass spectrometry; headspace analysis; nitrates; nitrites; organic matter; sodium sulfate; tap water;     Show all 12 Subjects
Abstract:
... A simple and efficient method has been developed for the extraction and determination of sixteen common volatile halogenated disinfection by-products (DBPs) using the static headspace (HS) technique coupled with gas chromatography–mass spectrometry (GC–MS). The DBPs determined included trihalomethanes (THMs), halonitromethanes (HNMs) and haloacetonitriles (HANs). The extraction parameters (HS cond ...
DOI:
10.1016/j.chroma.2013.08.036

13. Rapid and simultaneous determination of twenty amino acids in complex biological and food samples by solid-phase microextraction and gas chromatography–mass spectrometry with the aid of experimental design after ethyl chloroformate derivatization

Author:
Mudiam, Mohana Krishna Reddy; Ch., Ratnasekhar; Jain, Rajeev; Saxena, Prem Narain; Chauhan, Abhishek; Murthy, R.C.
Source:
Journal of chromatography 2012 v.907 pp. 56-64
ISSN:
1570-0232
Subject:
ionic strength,   etc   ; amino acids; biochemical pathways; biosynthesis; derivatization; detection limit; esters; experimental design; gas chromatography-mass spectrometry; hairs; hydrochloric acid; ionization; microwave radiation; nucleotides; pH; response surface methodology; secondary metabolites; solid phase microextraction; soybeans; urine; vitamins;     Show all 21 Subjects
Abstract:
... Amino acids play a vital role as intermediates in many important metabolic pathways such as the biosynthesis of nucleotides, vitamins and secondary metabolites. A sensitive and rapid analytical method has been proposed for the first time for the simultaneous determination of twenty amino acids using solid-phase microextraction (SPME). The protein samples were hydrolyzed by 6M HCl under microwave r ...
DOI:
10.1016/j.jchromb.2012.08.035

14. Head space solid phase microextraction based on nano-structured lead dioxide: Application to the speciation of volatile organoselenium in environmental and biological samples

Author:
Ghasemi, Ensieh; Farahani, Hadi
Source:
Journal of chromatography 2012 v.1258 pp. 16-20
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; desorption; detection limit; equations; experimental design; gas chromatography-mass spectrometry; headspace analysis; lead; mixing; platinum; screening; solid phase microextraction; temperature;     Show all 13 Subjects
Abstract:
... A novel and efficient speciation method based on the nano-structured lead dioxide as stationary phase of head space solid phase microextraction combined with gas chromatography mass spectrometry (GC–MS) was developed for the determination of volatile organoselenium compounds (dimethylselenide (DMSe) and dimethyldiselenide (DMDSe)) in different biological and environmental samples. PbO₂ particles w ...
DOI:
10.1016/j.chroma.2012.08.027

15. Application of ultrasound-assisted emulsification microextraction based on applying low-density organic solvent for the determination of organochlorine pesticides in water samples

Author:
Zhang, Yufeng; Lee, Hian Kee
Source:
Journal of chromatography 2012 v.1252 pp. 67-73
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; aqueous solutions; centrifugation; cost effectiveness; detection limit; dieldrin; emulsifying; emulsions; endrin; gas chromatography-mass spectrometry; heptachlor; hexachlorobenzene; iso-octanes; microextraction; pesticide residues; polyethylene; rivers; solvents; tap water; temperature; ultrasonics; water pollution;     Show all 22 Subjects
Abstract:
... In this study, a polyethylene Pasteur pipette-based ultrasound-assisted emulsification microextraction (USAEME) applying low-density organic solvent was successfully developed for the extraction of trace levels of organochlorine pesticides (OCPs) in water samples and followed by gas chromatography–mass spectrometry (GC–MS) analysis. In this approach, a polyethylene Pasteur squeeze-type pipette was ...
DOI:
10.1016/j.chroma.2012.06.065

16. Optimization of solvent bar microextraction combined with gas chromatography mass spectrometry for preconcentration and determination of tramadol in biological samples

Author:
Ghasemi, Ensieh
Source:
Journal of chromatography 2012 v.1251 pp. 48-53
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; detection limit; drugs; experimental design; gas chromatography-mass spectrometry; microextraction; mixing; monitoring; pH; polypropylenes; screening; solvents; temperature;     Show all 13 Subjects
Abstract:
... A simple, rapid and sensitive analytical method for preconcentration and determination of tramadol in different biological samples have been developed using solvent bar microextraction (SBME) combined with gas chromatography–mass spectrometry (GC–MS). The target drugs were extracted from 12ml of aqueous sample with pH 12.0 (source phase; SP) into an organic extracting solvent (n-nonanol) located i ...
DOI:
10.1016/j.chroma.2012.06.060

17. Determination of Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in water samples by solid-phase microextraction with on-fiber derivatization and gas chromatography–mass spectrometry

Author:
Racamonde, Inés; Villaverde-de-Sáa, Eugenia; Rodil, Rosario; Quintana, José Benito; Cela, Rafael
Source:
Journal of chromatography 2012 v.1245 pp. 167-174
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; cannabinoids; derivatization; detection limit; gas chromatography-mass spectrometry; pH; rivers; solid phase microextraction; temperature; wastewater; wastewater treatment;     Show all 11 Subjects
Abstract:
... A new method for the determination of two cannabinoids, Δ9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH), in wastewater samples is proposed using solid-phase microextraction (SPME) as extraction technique and gas chromatography coupled to mass spectrometry (GC–MS) as determination technique. Several parameters involved in SPME extraction were studied and optimiz ...
DOI:
10.1016/j.chroma.2012.05.017

18. Aniline–silica nanocomposite as a novel solid phase microextraction fiber coating

Author:
Bagheri, Habib; Roostaie, Ali
Source:
Journal of chromatography 2012 v.1238 pp. 22-29
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; aniline; coatings; desorption; detection limit; electrolytes; gas chromatography-mass spectrometry; headspace analysis; nanocomposites; nanoparticles; polycyclic aromatic hydrocarbons; rain; scanning electron microscopy; silica; solid phase microextraction; stainless steel; tap water; temperature;     Show all 18 Subjects
Abstract:
... A new unbreakable solid phase microextraction (SPME) fiber coating based on aniline–silica nanocomposite was electrodeposited on a stainless steel wire. The electropolymerization process was carried out at a constant deposition potential, applied to the corresponding aqueous electrolyte containing aniline and silica nanoparticles. The scanning electron microscopy (SEM) images showed the non-smooth ...
DOI:
10.1016/j.chroma.2012.03.027

19. One step solvent bar microextraction and derivatization followed by gas chromatography–mass spectrometry for the determination of pharmaceutically active compounds in drain water samples

Author:
Guo, Liang; Lee, Hian Kee
Source:
Journal of chromatography 2012 v.1235 pp. 26-33
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; agitation; derivatization; detection limit; drainage water; gas chromatography-mass spectrometry; ibuprofen; ketoprofen; liquid-phase microextraction; pH; propranolol; solid phase microextraction; solvents; temperature;     Show all 14 Subjects
Abstract:
... For the first time, a simple and novel one-step combined solvent bar microextraction with derivatization with GC–MS analysis, was developed for the determination of pharmaceutically active compounds (PhACs) in water samples. In the procedure, the derivatization reagent was added in the extraction solvent (solvent bar), so that the analytes could be extracted from the aqueous sample and simultaneou ...
DOI:
10.1016/j.chroma.2012.02.068

20. Development of multiwalled carbon nanotubes based micro-solid-phase extraction for the determination of trace levels of sixteen polycyclic aromatic hydrocarbons in environmental water samples

Author:
Guo, Liang; Lee, Hian Kee
Source:
Journal of chromatography 2011 v.1218 no.52 pp. 9321-9327
ISSN:
0021-9673
Subject:
ionic strength,   etc   ; United States Environmental Protection Agency; agitation; carbon nanotubes; desorption; detection limit; gas chromatography-mass spectrometry; polycyclic aromatic hydrocarbons; polypropylenes; river water; solvents; temperature; ultrasonic treatment;     Show all 13 Subjects
Abstract:
... Micro-solid-phase extraction (μ-SPE) was developed for the determination of trace level of 16 United States Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) in river water samples with gas chromatography–mass spectrometry (GC–MS). In the μ-SPE device, multiwalled carbon nanotubes was employed as sorbent and was packed inside an porous polypropylene membrane “envelop ...
DOI:
10.1016/j.chroma.2011.10.066