| 1. |
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| 2. |
- Geng, Dawei, 1986-, et al.
(författare)
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Gas chromatography/atmospheric pressure chemical ionization/mass spectrometry for the analysis of organochlorine pesticides and polychlorinated biphenyls in human serum
- 2016
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Ingår i: Journal of Chromatography A. - Amsterdam, Netherlands : Elsevier. - 0021-9673 .- 1873-3778. ; 1453, s. 88-98
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Tidskriftsartikel (refereegranskat)abstract
- A method using a novel atmospheric pressure chemical ionization source for coupling gas chromatography (GC/APCI) to triple quadrupole mass spectrometry (MS/MS) for the determination of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) regulated by the Stockholm Convention is presented. One microliter injection of a six-point calibration curve of native PCBs and OCPs, ranging from 0.04 to 300 pg/μL, was performed. The relative standard deviation (RSD) of the relative response factors (RRFs) was less than 15% with a coefficient of determination (r2) >0.995. Meanwhile, two calibration solutions (CS), CS 2 (0.4 pg/μL) and CS 3 (4 pg/μL) were analyzed to study the repeatability calculated for both area and RRFs. The RSD for RRF ranged from 3.1 to 16% and 3.6 to 5.5% for CS 2 and CS 3, respectively. The limits of detection (LOD) determined by peak-to-peak signal-to-noise ratio (S/N) of 3 were compared between the GC/APCI/MS/MS and a GC coupled to high resolution mass spectrometry (GC/HRMS) system. GC/APCI/MS/MS resulted in lower LOD for most of the compounds, except for PCB#74, cis-chlordane and trans-chlordane. GC/APCI/MS/MS and GC/HRMS were also compared by performing analysis on 75 human serum samples together with eight QA/QC serum samples. The comparison between GC/APCI/MS/MS system and GC/HRMS system for 16 of the targeted compounds was carried out. No statistically significant difference was discovered. Due to increased sensitivity and user friendly operation under atmospheric pressure, GC/APCI/MS/MS is a powerful alternative technique that can easily meet the specification of GC/HRMS.
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| 3. |
- Hagberg, Jessika, 1974-
(författare)
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Analysis of brominated dioxins and furans by high resolution gas chromatography/high resolution mass spectrometry
- 2009
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Ingår i: Journal of Chromatography A. - Amsterdam : Elsevier. - 0021-9673 .- 1873-3778. ; 1216:3, s. 376-384
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Forskningsöversikt (refereegranskat)abstract
- This article reviews the available literature on the analysis of brominated dibenzo-p dioxins and furans(PBDD/Fs) by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS).Sample extraction and clean up, injection techniques, chromatographic separation, labelled standardsand QA/QC works are discussed. Furthermore, full separation of PBDD/Fs from polybrominated diphenylethers (PBDEs) during clean up and control of possible chromatographic interference of PBDEs duringinstrumental analysis as well as possible actions to further enhance the quality of published data arediscussed in detail.
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| 4. |
- Hartonen, Minna, et al.
(författare)
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Characterization of cerebrospinal fluid by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry
- 2013
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1293, s. 142-149
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) was applied in the quantification and identification of organic compounds in patient-matched human cerebrospinal fluid (CSF) and serum samples. Concentrations of 21 amino and hydroxyl acids varied from 0.04 to 77ng/μl in CSF and from 0.1 to 84ng/μl in serum. In total, 91 metabolites out of over 1200 detected were identified based on mass spectra and retention indices. The other metabolites were identified at the functional group level. The main metabolites detected in CSF were sugar and amino acid derivatives. The CSF and serum had clearly distinct metabolic profiles, with larger biological variation in the serum than in CSF. The GC×GC-TOFMS allowed detection and identification of several metabolites that have not been previously detected in CSF.
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| 5. |
- Jin, Rong, et al.
(författare)
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Congener-specific determination of ultratrace levels of chlorinated and brominated polycyclic aromatic hydrocarbons in atmosphere and industrial stack gas by isotopic dilution gas chromatography/high resolution mass spectrometry method
- 2017
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1509, s. 114-122
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Tidskriftsartikel (refereegranskat)abstract
- Isotopic dilution gas chromatography combined with high resolution mass spectrometry (GC/HRMS) has overwhelming advantages with respect to the accuracy of congener-specific ultratrace analysis of complex persistent organic pollutants (POPs) in environmental matrices. However, an isotopic dilution GC/HRMS method for analysis of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) using 13C-labelled congeners as internal standards has not been established. In this study, a method for identification and quantification of 38 congeners of Cl-PAHs and Br-PAHs in atmosphere and stack gas samples from waste incinerators was developed using the isotopic dilution GC/HRMS technique. The instrumental detection limits of the GC/HRMS method ranged from 0.2pg to 1.8pg for Cl-PAH congeners, and 0.7pg to 2.7pg for Br-PAH congeners, which were about three orders of magnitude lower than those of the GC/quadrupole MS method. This new method developed was also the first to enable determination of Cl-PAH and Br-PAH homologs comprising congeners with the same molecular skeleton and chlorine or bromine substitution numbers. Among the detected congeners, seven Cl-PAH congeners and thirteen Br-PAH congeners that were abundant in the atmosphere and stack gases released from waste incinerators were firstly detected in real samples and reported using the established isotopic dilution GC/HRMS method. The developed isotopic dilution GC/HRMS is significant and needed for better studying the environmental behavior and health risk of Cl-PAHs and Br-PAHs.
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| 6. |
- Jönsson, Sofie, et al.
(författare)
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Analysis of nitroaromatic compounds in complex samples using solid-phase microextraction and isotope dilution quantification gas chromatography-electron-capture negative ionisation mass spectrometry
- 2007
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Ingår i: Journal of Chromatography A. - Amsterdam : Elsevier. - 0021-9673 .- 1873-3778. ; 1164:1-2, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- A solid-phase microextraction (SPME) method using gas chromatography–electron-capture negative ionisation mass spectrometry (GC–ECNI-MS) and isotope dilution quantification for the analysis of nitroaromatic compounds in complex, water based samples has been optimised. For ionisation, ECNI was the most sensitive and selective method. SPME was compared to solid-phase extraction (SPE) and found to be more sensitive for these small volume samples. LODs were in the range 0.02–38 ng L−1 for SPME and 6–184 ng L−1 for SPE, respectively. The SPME method was applied on samples in the ng L−1 level from artificial reed beds treated with sludge containing residues from explosives and pharmaceuticals.
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| 7. |
- Jönsson, Sofie, et al.
(författare)
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Determination of 2,4,6-trichloroanisole and 2,4,6-tribromoanisole on ng L-1 to pg L-1 levels in wine by soild-phase microextraction and gas chromatography-high-resolution mass spectrometry
- 2006
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1111:1, s. 71-75
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Tidskriftsartikel (refereegranskat)abstract
- A gas chromatography-high-resolution mass spectrometry (GC-HRMS) method using solid-phase microextraction (SPME) for the determination of 2,4,6-trichloroanisole (TCA) and 2,4,6-tribromoanisole (TBA) in wine at low ng L−1 levels was developed. A robust SPME method was developed by optimizing several different parameters, including type of fiber, salt addition, sample volume, extraction and desorption time. The quantification limit for TCA and TBA in wine was lowered substantially using GC-HRMS in combination with the optimized SPME method and allowed the detection of low analyte concentrations (ng L−1) with good accuracy. Limits of quantification for red wine of 0.3 ng L−1 for TCA and 0.2 ng L−1 for TBA with gas chromatography-negative chemical ionization mass spectrometry and 0.03 ng L−1 for TCA and TBA were achieved using GC-HRMS. The method was applied to 30 wines of which 4 wines were sensorically qualified as cork defected. TCA was found in three of these wines with concentrations in the range 2–25 ng L−1. TBA was not detected in any of the samples.
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| 8. |
- Katajamaa, Mikko, et al.
(författare)
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Data processing for mass spectrometry-based metabolomics
- 2007
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1158:1-2, s. 318-328
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Forskningsöversikt (refereegranskat)abstract
- Modern analytical technologies afford comprehensive and quantitative investigation of a multitude of different metabolites. Typical metabolomic experiments can therefore produce large amounts of data. Handling such complex datasets is an important step that has big impact on extent and quality at which the metabolite identification and quantification can be made, and thus on the ultimate biological interpretation of results. Increasing interest in metabolomics thus led to resurgence of interest in related data processing. A wide variety of methods and software tools have been developed for metabolomics during recent years, and this trend is likely to continue. In this paper we overview the key steps of metabolomic data processing and focus on reviewing recent literature related to this topic, particularly on methods for handling data from liquid chromatography mass spectrometry (LC-MS) experiments.
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| 9. |
- Kivilompolo, Marit, et al.
(författare)
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Rapid quantitative analysis of carnitine and acylcarnitines by ultra-high performance-hydrophilic interaction liquid chromatography-tandem mass spectrometry
- 2013
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1292, s. 189-194
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Tidskriftsartikel (refereegranskat)abstract
- L-Carnitine and its acyl esters (acylcarnitines) play an important role in the metabolism of fatty acids. However, most of the present methods for the quantitative analysis of acylcarnitines have restrictions both in sample preparation and in chromatographic separation. Herein we present a validated method for determination of carnitine and eleven acylcarnitines in human serum and rat tissue biopsies by using ultra-high performance-hydrophilic interaction liquid chromatography-tandem mass spectrometry (UHP-HILIC-MS/MS). The procedure uses minimal sample preparation including only addition of organic solvent, labeled internal standard, incubation and centrifugation. The separation is performed without derivatization or addition of ion-pairing reagent within 7 min on a hydrophilic interaction liquid chromatographic column with mass spectrometric detection. The method is linear in response over the concentration range from 20 to 600 ng/ml for carnitine and acetylcarnitine and 5-200 ng/ml for the other acylcarnitines, with correlation coefficients higher than 0.994. Recoveries were higher than 88% for most of the compounds. Limits of detection were 5 ng/ml for carnitine and acetylcarnitine and approximately 0.5 ng/ml for other acylcarnitines. The method was applied to the analysis of serum and tissue samples.
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| 10. |
- Lindström, Gunilla, et al.
(författare)
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Accuracy and precision in the determination of perfluorinated chemicals in human blood verified by interlaboratory comparisons
- 2009
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1216:3, s. 394-400
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Tidskriftsartikel (refereegranskat)abstract
- Perfluorinated chemicals, PFCs, are analyzed in laboratories worldwide to determine human blood levels and exposure pathways. The development of the nalytical echnique has been rapid in the last ten years, and prerequisites for accurate and precise determination of PFCs in human blood at low ng/g concentrations are today readily available. The main contributing factors are the improved LC-MS instrumentations, the increased availability of native and mass labeled PFC standards, and new column materials available for chromatographic separations. The results of the first international interlaboratory study (ILS) in 2005 on PFCs revealed relatively better analytical results for human blood analyses when compared to analyses of a number of environmental matrices. The representative accuracy for the analyses of PFCs in human matrixes reported in recent years was established in the second human serum ILS in 2006. Interlaboratory standard deviations for the two human serum samples one low level concentration and one medium level concentration were found to be 12% and 16% for PFOS, respectively, and 47% and 21% for PFOA, respectively. Reported detections for all PFCs followed a frequency of PFOS>PFOA>PFHxS>PFNA>PFDA>>PFDoA>> PFDS>>PFHxA. Due to the small number of reported values for the other perfluorosulfonates and perfluorocarboxylates, standard deviations were not established.
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