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You searched for: Publication Year 2012 Remove constraint Publication Year: 2012 Subject gas chromatography-mass spectrometry Remove constraint Subject: gas chromatography-mass spectrometry Subject ionization Remove constraint Subject: ionization Subject derivatization Remove constraint Subject: derivatization Text Availability Citation in PubAg Remove constraint Text Availability: Citation in PubAg
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1. 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:
amino acids; biochemical pathways; biosynthesis; derivatization; detection limit; esters; experimental design; gas chromatography-mass spectrometry; hairs; hydrochloric acid; ionic strength; ionization; microwave radiation; nucleotides; pH; response surface methodology; secondary metabolites; solid phase microextraction; soybeans; urine; vitamins
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

2. Determination of polycyclic aromatic hydrocarbons and their oxy-, nitro-, and hydroxy-oxidation products

Author:
Cochran, R.E.; Dongari, N.; Jeong, H.; Beránek, J.; Haddadi, S.; Shipp, J.; Kubátová, A.
Source:
Analytica chimica acta 2012 v.740 pp. 93-103
ISSN:
0003-2670
Subject:
air; derivatization; gas chromatography-mass spectrometry; ionization; methane; monitoring; oxidation; particulates; polycyclic aromatic hydrocarbons; smoke; solid phase extraction; temperature
Abstract:
... A sensitive method has been developed for the trace analysis of PAHs and their oxidation products (i.e., nitro-, oxy-, and hydroxy-PAHs) in air particulate matter (PM). Following PM extraction, PAHs, nitro-, oxy-, and hydroxy-PAHs were fractionated using solid phase extraction (SPE) based on their polarities. Gas chromatography–mass spectrometry (GC–MS) conditions were optimized, addressing inject ...
DOI:
10.1016/j.aca.2012.05.050

3. Molecularly imprinted-solid phase extraction combined with simultaneous derivatization and dispersive liquid–liquid microextraction for selective extraction and preconcentration of methamphetamine and ecstasy from urine samples followed by gas chromatography

Author:
Djozan, Djavanshir; Farajzadeh, Mir Ali; Sorouraddin, Saeed Mohammad; Baheri, Tahmineh
Source:
Journal of chromatography 2012 v.1248 pp. 24-31
ISSN:
0021-9673
Subject:
aqueous solutions; centrifugation; derivatization; detection limit; drugs; gas chromatography-mass spectrometry; humans; ionization; liquid-phase microextraction; methanol; molecular imprinting; polymerization; solid phase extraction; solvents; urine
Abstract:
... In this study, a developed technique was reported for extraction and pre-concentration of methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) from urine samples using molecularly imprinted-solid phase extraction (MISPE) along with simultaneous derivatization and dispersive liquid–liquid microextraction (DLLME). Molecularly imprinted microspheres as sorbent in solid phase e ...
DOI:
10.1016/j.chroma.2012.05.085

4. Improving methodological aspects of the analysis of five regulated haloacetic acids in water samples by solid-phase extraction, ion-pair liquid chromatography and electrospray tandem mass spectrometry

Author:
Prieto-Blanco, M.C.; Alpendurada, M.F.; López-Mahía, P.; Muniategui-Lorenzo, S.; Prada-Rodríguez, D.; Machado, S.; Gonçalves, C.
Source:
Talanta 2012 v.94 pp. 90-98
ISSN:
0039-9140
Subject:
adsorbents; correlation; derivatization; detection limit; disinfection; drinking water; energy; gas chromatography-mass spectrometry; haloacetic acids; ionization; ions; liquid chromatography; monitoring; pollutants; quality control; solid phase extraction; spectrometers; tandem mass spectrometry; triethylamine
Abstract:
... Haloacetic acids (HAAs) are organic pollutants originated from the drinking water disinfection process, which ought to be controlled and minimized. In this work a method for monitoring haloacetic acids (HAAs) in water samples is proposed, which can be used in quality control laboratories using the techniques most frequently available. Among its main advantages we may highlight its automated charac ...
DOI:
10.1016/j.talanta.2012.02.061

5. Negative Chemical Ionization GC/MS Determination of Nitrite and Nitrate in Seawater Using Exact Matching Double Spike Isotope Dilution and Derivatization with Triethyloxonium Tetrafluoroborate

Author:
Pagliano, Enea; Meija, Juris; Sturgeon, Ralph E.; Mester, Zoltan; D’Ulivo, Alessandro
Source:
Analytical chemistry 2012 v.84 no.5 pp. 2592-2596
ISSN:
1520-6882
Subject:
alkylation; derivatization; detection limit; esters; gas chromatography-mass spectrometry; headspace analysis; ionization; isotope dilution technique; monitoring; nitrates; nitrites; nitrogen dioxide; oxygen; seawater; solvents
Abstract:
... The alkylation of nitrite and nitrate by triethyloxonium tetrafluoroborate allows determination of their ethyl esters by headspace gas chromatography/mass spectrometry (GC/MS). In the present study, significant improvement in analytical performance is achieved using negative chemical ionization providing detection limits of 150 ng/L for NO₂– and 600 ng/L for NO₃–, an order of magnitude better than ...
DOI:
10.1021/ac2030128

6. Sample preparation method for the speciation of polybrominated diphenyl ethers and their methoxylated and hydroxylated analogues in diverse environmental matrices

Author:
Sun, Jianteng; Liu, Jiyan; Liu, Qian; Qu, Guangbo; Ruan, Ting; Jiang, Guibin
Source:
Talanta 2012 v.88 pp. 669-676
ISSN:
0039-9140
Subject:
cleaning; derivatization; detection limit; fish; gas chromatography-mass spectrometry; ionization; liquid chromatography; molluscs; polybrominated diphenyl ethers; sediments; silica gel; soil
Abstract:
... A reliable analytical method was developed here for the simultaneous separation, identification and quantification of ten polybrominated diphenyl ethers (PBDEs), nine methoxylated PBDEs (MeO-PBDEs) and ten hydroxylated PBDEs (OH-PBDEs) in various environmental matrices, including water, soil, sediment, plant, mollusk and fish. PBDEs and MeO-PBDEs were measured by gas chromatography coupled with ma ...
DOI:
10.1016/j.talanta.2011.11.059