共查询到20条相似文献,搜索用时 31 毫秒
1.
Kallio M Jussila M Raimi P Hyötyläinen T 《Analytical and bioanalytical chemistry》2008,391(6):2357-2363
A previously constructed semi-rotating cryogenic modulator was modified for comprehensive two-dimensional gas chromatography
(GC×GC). The retention time repeatability was improved by replacing the modulator control program unit with a new system.
Peak widths obtained with the modified modulator were comparable with those obtained with the previous modulator and other
modulator types. The modulator was easy to construct and it can be installed in any commercial GC system. The constructed
GC×GC–FID system and data obtained by gas chromatography–mass spectrometry (GC–MS) were used for identification of unknowns
in forest aerosol samples.
Figure A semi-rotating cryogenic modulator in which modulation is based on two-step cryogenic trapping with continuously flowing
carbon dioxide has been developed for comprehensive two-dimensional gas chromatography 相似文献
2.
Sergi M Bafile E Compagnone D Curini R D'Ascenzo G Romolo FS 《Analytical and bioanalytical chemistry》2009,393(2):709-718
An analytical procedure for the simultaneous determination in human plasma and oral fluids of several illicit drugs belonging
to different chemical and toxicological classes is presented. Amphetamine, methamphetamine, morphine, 6-monoacetylmorphine,
methylenedioxyamphetamine, methylenedioxyethylamphetamine, methylenedioxymethamphetamine, cocaine, benzoylecgonine, tetrahydrocannabinol,
carboxytetrahydrocannabinol, ketamine, and phencyclidine have been quantified in real samples using a very rapid sample treatment,
basically a protein precipitation. The quantitative analysis was performed by liquid chromatography–tandem mass spectrometry
and has been fully validated. All the analytes were detected in positive ionization mode using a TurboIonSpray source, except
carboxytetrahydrocannabinol, which was detected in negative ionization mode. The use of a diverter valve between the column
and the mass spectrometer allows the preservation of the ion source performances for high-throughput analysis.
Figure Diverter system 相似文献
3.
Fanny Kieken Gaud Pinel Jean-Philippe Antignac Fabrice Monteau Anne Christelle Paris Marie-Agnès Popot Yves Bonnaire Bruno Le Bizec 《Analytical and bioanalytical chemistry》2009,394(8):2119-2128
Despite the worldwide existing regulation banning the use of the recombinant equine growth hormone (reGH) as growth promoter,
it is suspected to be used in horseracing to improve performances. Various analytical methods previously developed to screen
for its misuse have encountered some limitations in terms of detection timeframes, in particular during the first days following
reGH administration. A novel strategy involving the characterization of global metabolomic fingerprints in urine samples of
non-treated and reGH-treated horses by liquid chromatography–electrospray–high-resolution mass spectrometry (LC-ESI-HRMS)
is described and assessed in this paper in order to develop a new screening tool for growth hormone abuse in horseracing.
The strategy involves a limited sample preparation of the urine samples and the use of appropriate software for data processing
and analysis. As preliminary work, reproducibility of both sample preparation and mass spectrometry (MS) measurements was
evaluated in order to demonstrate the reliability of the method. Application of the developed protocol on two horses demonstrated
the suitability of the developed strategy and preliminary results showed significant modifications of the metabolome after
treatment with reGH.
相似文献
4.
Stir bar sorptive extraction in combination with thermal desorption coupled online to capillary gas chromatography–mass spectrometry
was applied to investigate volatile and semivolatile fractions in two waste leachate samples: old and fresh ones. The present
study helps to improve our knowledge of waste leachate organic composition. The aim is to then make use of this knowledge
afterwards in order to generate more reliable and specific treatment processes for waste leachates and thus to respect the
environmental statute law regarding their rejection. The volatile and semivolatile compounds appeared to be mainly anthropogenic
in origin. Moreover, lactic acid and cyclic octaatomic sulfur could potentially be used as microbiological activity indicators,
since they occur during organic matter degradation processes within waste leachates.
Figure TDU-CGC-MS analytical equipment 相似文献
5.
Various toxicological and metabolic interactions have been reported to exist between arsenic and selenium. In the present
study, synthetic seleno-arsenic compounds, potentially suitable for probing metabolic interactions between these two elements,
were prepared and tentatively characterized by using high-performance liquid chromatography (HPLC)–electrospray tandem mass
spectrometry and HPLC–inductively coupled plasma mass spectrometry. In analogy to the recently identified thio-arsenic species,
which can be prepared from their corresponding oxo-arsenic species via reaction with H2S, the seleno-arsenic compounds were also derived from oxo-arsenic compounds via reaction with H2Se.
Figure H2Se bubbled into solutions containing oxo‐arsenosugars converts them into their seleno‐arsenosugar analogues. 相似文献
6.
In-torch LA–ICP–MS was implemented into an in-house-built ICP–TOFMS system. The fast data acquisition capabilities of the
new configuration allowed simultaneous multi-element measurement and readout of in-torch LA–ICP–MS signals with 30 μs time
resolution. The measurements confirmed previously observed fine structures of in-torch generated signals and provided new
insights in the dynamic processes in the plasma on a microsecond time scale. The new setup is described in detail and first
figures of merit are given.
Figure Time dependent multi element signal after laser ablation in the torch of an ICP-TOFMS instrument 相似文献
7.
Jackson AT Slade SE Thalassinos K Scrivens JH 《Analytical and bioanalytical chemistry》2008,392(4):643-650
The end-group functionalisation of a series of poly(propylene glycol)s has been characterised by means of electrospray ionisation–tandem
mass spectrometry (ESI-MS/MS). A series of peaks with mass-to-charge ratios that are close to that of the precursor ion were
used to generate information on the end-group functionalities of the poly(propylene glycol)s. Fragment ions resulting from
losses of both of the end groups were noted from some of the samples. An example is presented of how software can be used
to significantly reduce the length of time involved in data interpretation (which is typically the most time-consuming part
of the analysis).
Figure Screenshot from Polymerator software of annotated ESI-MS/MS spectrum from the lithiated heptamer of poly(propylene glycol)
di-acrylate 相似文献
8.
Barr DB Leng G Berger-Preiss E Hoppe HW Weerasekera G Gries W Gerling S Perez J Smith K Needham LL Angerer J 《Analytical and bioanalytical chemistry》2007,389(3):811-818
The objective of our study was to compare three vastly different analytical methods for measuring urinary metabolites of pyrethroid
and pyrethrum insecticides to determine whether they could produce comparable data and to determine if similar analytical
characteristics of the methods could be obtained by a secondary laboratory. This study was conducted as a part of a series
of validation studies undertaken by the German Research Foundation’s Committee on the Standardization of Analytical Methods
for Occupational and Environmental Medicine. We compared methods using different sample preparation methods (liquid–liquid
extraction and solid-phase extraction with and without chemical derivatization) and different analytical detection methods
(gas chromatography–mass spectrometry (single quadrupole), gas chromatography–high resolution mass spectrometry (magnetic
sector) in both electron impact ionization and negative chemical ionization modes, and high-performance liquid chromatography–tandem
mass spectrometry (triple quadrupole) with electrospray ionization). Our cross validation proved that similar analytical characteristics
could be obtained with any combination of sample preparation/analytical detection method and that all methods produced comparable
analytical results on unknown urine samples.
Cross-method comparison using unknown urine samples revealed reasonably good agreement for any combination of the methods
tested 相似文献
9.
An X-ray fluorescence method (XRF) is presented that allowed low detection limits (at the 0.1–23 ng mL−1 level) to be obtained for Cr, Mn, Fe, Ni, Zn, Sr, Pb, Bi and Br in water. The samples were prepared using a thin layer method. Trace elements were determined via the calibration curve and standard addition. Absorption effects and inhomogenities in prepared samples were checked for using the emission–transmission method and internal standards, respectively. The results from the XRF method were compared with the results from the inductively coupled plasma atomic emission spectrometry method.
相似文献
10.
Pérez Pavón JL García Pinto C Guerrero Peña A Moreno Cordero B 《Analytical and bioanalytical chemistry》2008,391(2):599-607
In the present work we report the results obtained with a methodology based on direct coupling of a headspace generator to
a mass spectrometer for the identification of different types of petroleum crudes in polluted soils. With no prior treatment,
the samples are subjected to the headspace generation process and the volatiles generated are introduced directly into the
mass spectrometer, thereby obtaining a fingerprint of volatiles in the sample analysed. The mass spectrum corresponding to
the mass/charge ratios (m/z) contains the information related to the composition of the headspace and is used as the analytical signal for the characterization
of the samples. The signals obtained for the different samples were treated by chemometric techniques to obtain the desired
information. The main advantage of the proposed methodology is that no prior chromatographic separation and no sample manipulation
are required. The method is rapid, simple and, in view of the results, highly promising for the implementation of a new approach
for oil spill identification in soils.
Figure PCA score plots illustrate clear discrimination of types of crude oil in polluted soil samples (e.g. results are shown for
vertisol) 相似文献
11.
Aguinaga N Campillo N Viñas P Hernández-Córdoba M 《Analytical and bioanalytical chemistry》2008,391(4):1419-1424
This paper describes a headspace solid-phase microextraction (HS-SPME) procedure coupled to gas chromatography with mass spectrometric
detection (GC–MS) for the determination of eight PAHs in aquatic species. The influence of various parameters on the PAH extraction
efficiency was carefully examined. At 75 °C and for an extraction time of 60 min, a polydimethylsiloxane–divinylbenzene (PDMS/DVB)
fiber coating was found to be most suitable. Under the optimized conditions, detection limits ranged from 8 to 450 pg g−1, depending on the compound and the sample matrix. The repeatability varied between 7 and 15% (RSD). Accuracy was tested using
the NIST SRM 1974b reference material. The method was successfully applied to different samples, and the studied PAHs were
detected in several of the samples.
Figure Headspace SPME sampling followed by GC–MS facilitates routine monitoring of PAHs in aquatic species 相似文献
12.
Rosenberg E 《Analytical and bioanalytical chemistry》2008,391(1):33-57
This review discusses the characterisation of natural organic dyestuffs of historical interest by liquid chromatography–mass
spectrometry. The structures of the most important natural organic dyestuffs traditionally used are presented and discussed
from the perspective of their analytical chemical determination. The practical aspects of the determination of this inhomogeneous
range of compounds with different structures, such as anthraquinones, flavonoids, indigoids or tannins, are discussed with
their implications for sample preparation, liquid chromatographic separation and mass spectrometric detection. The particular
focus of this review is the discussion of the mass spectral fragmentation patterns of the different classes of natural organic
dyestuffs, which in the ideal case allow the identification of the dyestuff actually used, and thereby provide a key to the
better characterisation and understanding of historical objects dyed with natural organic dyestuffs.
Figure LC-MS allows characterisation of natural dyestuff constituents: the MS spectrum of alizarin is superimposed over a photo of
a textile coloured using this red dye 相似文献
13.
Nirogi RV Kandikere VN Shukla M Mudigonda K Shrivasthava W Datla PV Yerramilli A 《Analytical and bioanalytical chemistry》2006,384(3):780-790
A simple, rapid, sensitive and selective liquid chromatography/electrospray tandem mass spectrometry method was developed
and validated for the simultaneous quantification of cilostazol and its primary metabolite 3,4-dehydrocilostazol in human
plasma using mosapride as an internal standard. The method involves a simple one-step liquid-liquid extraction with a diethyl
ether and dichloromethane mixture (7:3). The analytes were chromatographed using an isocratic mobile phase on a reversed-phase
C18 column and analyzed by mass spectrometry in the multiple reaction monitoring mode using the respective [M+H]+ ions, m/z 370/288 for cilostazol, m/z 368/286 for 3,4-dehydrocilostazol and m/z 422/198 for the internal standard. The assay exhibited a linear dynamic range of 5–2,000 ng/mL for cilostazol and 5–400 ng/mL
for 3,4-dehydrocilostazol in human plasma. The lower limit of quantitation was 5 ng/mL for both cilostazol and its metabolite.
Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. A run time of 2.5 min for
each sample made it possible to analyze more than 400 human plasma samples per day. The validated method has been successfully
used to analyze human plasma samples for application in pharmacokinetics, bioavailability or bioequivalence studies.
相似文献
14.
Pisonero J Kroslakova I Günther D Latkoczy C 《Analytical and bioanalytical chemistry》2006,386(1):12-20
The spatial distribution and concentration of impurities in metallurgical-grade silicon (MG-Si) samples (97–99% w/w Si) were investigated by use of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The spatial resolution
(120 μm) and low limits of detection (mg kg−1) for quality assurance of such materials were studied in detail. The volume-dependent precision and accuracy of non-matrix-matched
calibration for quantification of minor elements, using NIST SRM 610 (silicate standard), indicates that LA-ICP-MS is well
suited to rapid process control of such materials. Quantitative results from LA-ICP-MS were compared with previously reported
literature data obtained by use of ICP-OES and rf-GD-OES. In particular, the distribution of element impurities and their
relationship to their different segregation coefficients in silicon is demonstrated.
Dedicated to Professor Klaus G. Heumann 相似文献
15.
Aguinaga N Campillo N Viñas P Hernández-Córdoba M 《Analytical and bioanalytical chemistry》2008,391(3):753-758
A sensitive and solvent-free method for the determination of ten polycyclic aromatic hydrocarbons, namely, naphthalene, acenaphthylene,
acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene and chrysene, with up to four aromatic rings, in milk samples using headspace solid-phase microextraction and
gas chromatography–mass spectrometry detection has been developed. A polydimethylsiloxane–divinylbenzene fiber was chosen
and used at 75°C for 60 min. Detection limits ranging from 0.2 to 5 ng L−1 were attained at a signal-to-noise ratio of 3, depending on the compound and the milk sample under analysis. The proposed
method was applied to ten different milk samples and the presence of six of the analytes studied in a skimmed milk with vegetal
fiber sample was confirmed. The reliability of the procedure was verified by analyzing two different certified reference materials
and by recovery studies.
Figure Milk is safe, healthy food 相似文献
16.
Acetone plays an important role in the chemistry of both the atmosphere and the ocean, due to its potential effect on the
tropospheric HOx (= HO + HO2) budget, as well as its environmental and health effects. We discuss the development of a mobile, sensitive, selective, economical
and facile method for the determination of acetone in seawater. The method consists of derivatizing acetone to its pentafluorobenzyl
oxime using 1,2,3,4,5-pentafluorobenzylhydroxylamine (PFBHA), followed by solid-phase microextraction (SPME) and analysis
by gas chromatography/mass spectrometry (GC/MS). A detection limit of 3.0 nM was achieved. The buffering capacity of seawater
imposes challenges in using the method’s optimum pH (3.7) on seawater samples, requiring calibration standards to be made
in buffered salt water and the acidification of seawater samples and standards prior to extraction. We employed the technique
for analysis of selected surface seawater samples taken on the Nordic seas during the ARK-XX/1 cruise (R.V. Polarstern). An upper limit of 5.5–9.6 nM was observed for acetone in these waters, the first acetone measurements reported for far
North Atlantic and Arctic waters.
Simplified schematic of transformations of organic compounds at the atmosphere–ocean interface 相似文献
17.
Oberacher H 《Analytical and bioanalytical chemistry》2008,391(1):135-149
After completion of the human genome sequence the search for differences among individual genomes has become the centre of
focus for geneticists. Two different types of polymorphism—single nucleotide polymorphisms (SNPs) and short tandem repeats
(STRs)—are major sources of genetic diversity and are of widespread use in genetic analysis. A plethora of genotyping techniques
have been developed, and mass spectrometry (MS) is among the most widely used analytical platforms. The most striking advantage
of mass spectrometric genotyping assays over others is the use of the measured molecular mass information for allele calling.
The molecular mass is less error-prone than other sequence-specific parameters, including migration times, retention times,
or hybridization yields, as it represents an intrinsic property of a nucleic acid molecule that is directly related to its
nucleotide composition. Mass spectrometric assays can roughly be divided into two major groups—matrix-assisted laser desorption/ionization
(MALDI)-based and electrospray ionization (ESI)-based assays. An important subdivision of ESI-based genotyping methods are
approaches that originate from the hyphenation of liquid chromatography (LC) to MS. The principles of these three classes
of mass spectrometric genotyping techniques are summarized in this review. Possibilities and limitations are critically discussed
to assist scientists, especially non-experts in MS, in choosing the appropriate mass spectrometric assay for genotyping a
genetic marker of interest.
Figure Comparison of the principle workflows applied for the characterization of genetic markers by MALDI–MS, ESI–MS, and LC–MS 相似文献
18.
Krupp EM Milne BF Mestrot A Meharg AA Feldmann J 《Analytical and bioanalytical chemistry》2008,390(7):1753-1764
Mercury in plants or animal tissue is supposed to occur in the form of complexes formed with biologically relevant thiols
(biothiols), rather than as free cation. We describe a technique for the separation and molecular identification of mercury
and methylmercury complexes derived from their reactions with cysteine (Cys) and glutathione (GS): Hg(Cys)2, Hg(GS)2, MeHgCys, MeHgGS. Complexes were characterised by electrospray mass spectrometry (MS) equipped with an ion trap and the fragmentation
pattern of MeHgCys was explained by using MP2 and B3LYP calculations, showing the importance of mercury–amine interactions
in the gas phase. Chromatographic baseline separation was performed within 10 min with formic acid as the mobile phase on
a reversed-phase column. Detection was done by online simultaneous coupling of ES-MS and inductively coupled plasma MS. When
the mercury complexes were spiked in real samples (plant extracts), no perturbation of the separation and detection conditions
was observed, suggesting that this method is capable of detecting mercury biothiol complexes in plants.
Figure Separation and structural identification of Hg and MeHg biothiols
A part of this work was presented as a poster at the European Winter Conference on Plasma Spectrochemistry, 2007, held in
Taormina, Italy. 相似文献
19.
Rodríguez-Fariñas N Gomez-Gomez MM Camara-Rica C 《Analytical and bioanalytical chemistry》2008,390(1):29-35
Oral administration of sodium tungstate is an effective treatment for type 1 and 2 diabetes in animal models; it does not
incur significant side effects, and it may constitute an alternative to insulin. However, the mechanism by which tungstate
exerts its observed metabolic effects in vivo is still not completely understood. In this work, serum-containing proteins
which bind tungstate have been characterized. Size exclusion chromatography (SEC) coupled to inductively coupled plasma mass
spectrometry (ICP-MS) with a Phenomenex Bio-Sep-S 2000 column and 20 mM HEPES and 150 mM NaCl at pH 7.4 as the mobile phase
was chosen as the most appropriate methodology to screen for tungsten–protein complexes. When human serum was incubated with
tungstate, three analytical peaks were observed, one related to tungstate–albumin binding, one to free tungstate, and one
to an unknown protein binding (MW higher than 300 kDa). Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF)
mass spectrometric analysis of the tungsten-containing fractions collected from SEC–ICP-MS chromatograms, after desalting
and preconcentration processes, confirmed the association of tungstate with albumin and the other unknown protein.
Figure SEC-ICP-MS // MALDI-TOF 相似文献
20.
Cuyckens F Balcaen LI De Wolf K De Samber B Van Looveren C Hurkmans R Vanhaecke F 《Analytical and bioanalytical chemistry》2008,390(7):1717-1729
A combination of inductively coupled plasma mass spectrometry (ICP-MS) and electrospray ionization mass spectrometry (ESI-MS)
was deployed for the metabolite profiling and metabolite identification of a new antituberculosis compound (R207910, also
known as TMC207) that is currently in drug development. R207910 contains one bromine atom, allowing the detection by ICP-MS.
Fluctuations in the Br sensitivity caused by the HPLC gradient were counteracted by the use of species-unspecific isotope
dilution. In order to evaluate the method developed, the results obtained were compared with those acquired via radioactivity
detection. HPLC-ESI-MS was used for the structural identification of R207910 and its metabolites. The 79Br/81Br isotope ratio is also valuable in the search for metabolites in the complex background of endogenous compounds obtained
using HPLC-ESI-MS analyses. Data-dependent scanning using isotope recognition with an ion trap mass spectrometer or processing
of Q-Tof data provides HPLC-ICP-MS-like “bromatograms”. The combination of accurate mass measurements and the fragmentation
behavior in the MS2 spectra obtained using the Q-Tof Ultima mass spectrometer or MSn spectra acquired using the LTQ-Orbitrap allowed structural characterization of the main metabolites of R207910 in methanolic
dog and rat faeces extracts taken 0–24 h post-dose.
Figure Analyses of a rat faeces extract taken 0–24 h post-dose: a HPLC-ICP-MS using isotope dilution, b corresponding Br mass flow chromatogram, c radio-HPLC, d Q-Tof ESI-MS TIC, e Q-Tof ESI-MS bromatogram after Br stripping, f LTQ-Orbitrap ESI-MS2 TIC obtained with isotopic-data-dependent scanning 相似文献