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1.
Simone Schiesel Michael Lämmerhofer Wolfgang Lindner 《Analytical and bioanalytical chemistry》2010,396(5):1655-1679
The presented work deals with the development and comprehensive validation of a quantitative LC–electrospray ionization (ESI)–tandem
mass spectrometry (MS/MS) method using a triple quadrupole instrument in the MRM mode for the metabolic profiling of amino
acids, organic acids, vitamins, some biogenic amines, secondary metabolites of β-lactam antibiotics biosynthesis as well as
their intermediates, and degradation products in fermentation broths of β-lactam antibiotics production (in total 57 hydrophilic
compounds). A great number of chromatographic systems (22 different stationary phase/mobile phase conditions) were screened
for their adequate chromatographic selectivity to cope with isobaric compounds and other critical analyte pairs. Finally,
a hydrophilic interaction liquid chromatography (HILIC) method employing a zwitterionic ZIC-HILIC column was selected as best
compromise. Particular focus was given on the elucidation of absolute and relative matrix effects via comparison of slopes
of calibration functions of spiked matrix and standard solutions. These data as well as precision and accuracy data confirm
suitability of the HILIC–ESI–MS/MS assay for metabolic profiling studies in fermentation samples. Detailed comprehensive data
sets are presented which should illustrate critical issues, problems, and challenges of multitarget quantitative metabolic
profiling and should outline possible strategies to circumvent pitfalls and overcome common problems. 相似文献
2.
Gero P. Hooff Nina Patel W. Gibson Wood Walter E. Müller Gunter P. Eckert Dietrich A. Volmer 《Analytical and bioanalytical chemistry》2010,398(4):1801-1808
The isoprenoids farnesyl-(FPP) and geranylgeranylpyrophosphate (FPP and GGPP) are two major lipid intermediates in the mevalonate
pathway. They participate in post-translational modification of members of the superfamily of small guanosine triphosphatases
(GTPases; Ras, Rab, Rac, etc.) via prenylation reactions. Due to the important role of these proteins in a number of cell
processes, in particular cell growth, division, and differentiation, investigation of the involvement of isoprenoids in these
processes is of great interest. In a previously published report, we described a fully validated assay for the quantitation
of the two isoprenoids using a high-performance liquid chromatography (HPLC)–fluorescence detection (FLD) method. The current
work expands on the previous method and enhances it greatly by using a much faster state-of-the-art ultrahigh-performance
liquid chromatography (UHPLC) technique coupled to tandem mass spectrometry (MS/MS). The method exhibited a linear concentration
range of 5–250 ng/mL for FPP and GGPP in human brain tissue; it was shown to be unaffected by ion suppression and provided
results almost six times faster than the HPLC–FLD assay. Comparison of UHPLC–MS/MS and HPLC–FLD yielded excellent comparability
of the two assays for both isoprenoids. Based on the UHPLC–MS/MS assay, a novel in vitro test system was implemented to study
enzyme specificity for distinct amino acid CAAX motifs, which is potentially useful for investigating target interactions
of new therapeutics for diseases involving pathological regulation of isoprenoids and/or small GTPases. 相似文献
3.
Mol HG Rooseboom A van Dam R Roding M Arondeus K Sunarto S 《Analytical and bioanalytical chemistry》2007,389(6):1715-1754
The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas
chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary–secondary amine and graphitized
carbon black) and large-volume (20 μL) injection. The same extract, before clean-up and after a change of solvent, was also
analyzed by liquid chromatography with tandem mass spectrometry (LC–MS–MS). All aspects related to sample preparation were
re-assessed with regard to ease and speed of the analysis. The principle of the extraction procedure (solvent, salt) was not
changed, to avoid the possibility invalidating data acquired over past decades. The modifications were made with techniques
currently commonly applied in routine laboratories, GC–MS and LC–MS–MS, in mind. The modified method enables processing (from
homogenization until final extracts for both GC and LC) of 30 samples per eight hours per person. Limits of quantification
(LOQs) of 0.01 mg kg−1 were achieved with both GC–MS (full-scan acquisition, 10 mg matrix equivalent injected) and LC–MS–MS (2 mg injected) for
most of the pesticides. Validation data for 341 pesticides and degradation products are presented. A compilation of analytical
quality-control data for pesticides routinely analyzed by GC–MS (135 compounds) and LC–MS–MS (136 compounds) in over 100 different
matrices, obtained over a period of 15 months, are also presented and discussed. At the 0.05 mg kg−1 level acceptable recoveries were obtained for 93% (GC–MS) and 92% (LC–MS–MS) of pesticide–matrix combinations. 相似文献
4.
Aguilera-Luiz MM Plaza-Bolaños P Romero-González R Vidal JL Frenich AG 《Analytical and bioanalytical chemistry》2011,399(8):2863-2875
A rapid multi-analyte method has been developed for the simultaneous determination of pesticides and mycotoxins in milk by
ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC–QqQ–MS/MS). A variety of
methodologies has been evaluated, including solid-phase extraction (SPE), “dilute-and-shoot” (liquid–liquid extraction-based
procedures), and QuEChERS (quick, easy, cheap, effective, rugged, and safe)-based methods. The optimization and development
process was carried out considering that the maximum residue level for aflatoxin M1 (AFM1) in milk in the European Union (EU)
is set at 0.05 μg kg−1, which is the lowest tolerance in the target compounds. The selected method consisted of an extraction by SPE using C18 as
sorbent and methanol as elution solvent. The final determination was performed by UHPLC–QqQ–MS/MS. Matrix-matched standard
calibration was used for quantification, obtaining recoveries in the range 60–120% with relative standard deviations <25%,
at three spiking levels: 0.5, 10, and 50 μg kg−1 (ten times lower for AFM1). Limits of quantification ranged from 0.20 to 0.67 μg kg−1, which were always below or equal to the established tolerance levels by the EU. Finally, the selected method was applied
to different types of milk. 相似文献
5.
Gas chromatography with spectroscopic detectors. 总被引:2,自引:0,他引:2
N Ragunathan K A Krock C Klawun T A Sasaki C L Wilkins 《Journal of chromatography. A》1999,856(1-2):349-397
In recent years, capillary gas chromatography (GC) with Fourier Transform Infrared (FT-IR) and/or mass spectral (MS) detection has become a primary analytical tool for qualitative and quantitative analysis of complex mixtures. Because of the wide range of applications, the analytical requirements have motivated a variety of chromatographic and detection developments. This review examines those, illustrating with applications that demonstrate the power of GC and multidimensional GC-MS, GC-FT-IR and GC-FT-IR-MS systems for solving a variety of analytical problems. In addition, the article discusses the integrated performance of such analytical systems with the aid of recent sample introduction and computer data analysis advances. 相似文献
6.
E. Pitarch T. Portolés J. M. Marín M. Ibáñez F. Albarrán F. Hernández 《Analytical and bioanalytical chemistry》2010,397(7):2763-2776
The presence of a wide variety of organic pollutants with different physicochemical characteristics has been investigated
in wastewater samples from a municipal solid-waste-treatment plant in Castellón, Spain. An advanced analytical strategy was
applied—combined used of two powerful and complementary techniques, GC and LC, both hyphenated with tandem mass spectrometry
with triple-quadrupole analyzers. The GC–MS–MS method was based on sample extraction using C18 SPE cartridges and enabled the determination of approximately 60 compounds from different chemical families, for example
PAHs, octyl/nonylphenols, PCBs, organochlorine compounds, insecticides, herbicides, and PBDEs. Most of the compounds selected
are included as priority contaminants in the European Union (EU) Water Directive. The UHPLC–MS–MS method, which provided high
chromatographic resolution and sensitivity and short analysis time, used sample extraction with Oasis HLB SPE cartridges and
enabled the determination of 37 (more polar) pesticides. The methodology developed was applied to the analysis of 41 water
samples (20 untreated raw leachates and 21 treated samples) collected between March 2007 and February 2009. Amounts of the
contaminants investigated rarely exceeded 0.5 μg L−1 in the treated (reverse osmosis) water samples analyzed. As expected, in untreated leachates the number of compounds detected
and the concentrations found were notably higher than in treated waters. The most commonly detected pollutants were herbicides
(simazine, terbuthylazine, terbutryn, terbumeton, terbacil, and diuron), fungicides (thiabendazole and carbendazim), and 4-t-octylphenol. The results obtained proved that use of reverse osmosis for water treatment was efficient and notably reduced
the amounts of organic contaminants found in raw leachate samples. In order to investigate the presence of other non-target
contaminants, water samples were also analyzed by using GC–TOF MS and LC–QTOF MS. Several organic pollutants that did not
form a part of the previous list of target contaminants were identified in the samples, because of the high sensitivity of
TOF MS in full-spectrum acquisition mode and the valuable accurate-mass information provided by these instruments. The insecticide
diazinon, the fungicide diphenylamide, the UV filter benzophenone, N-butylbenzenesulfonamide (N-BBSA), the insect repellent diethyltoluamide, caffeine, and the pharmaceuticals erythromycin,
benzenesulfonanilide, ibuprofen, atenolol, and paracetamol were some of the compounds identified in the water samples analyzed. 相似文献
7.
Watson NE Vanwingerden MM Pierce KM Wright BW Synovec RE 《Journal of chromatography. A》2006,1129(1):111-118
A useful methodology is introduced for the analysis of data obtained via gas chromatography with mass spectrometry (GC-MS) utilizing a complete mass spectrum at each retention time interval in which a mass spectrum was collected. Principal component analysis (PCA) with preprocessing by both piecewise retention time alignment and analysis of variance (ANOVA) feature selection is applied to all mass channels collected. The methodology involves concatenating all concurrently measured individual m/z chromatograms from m/z 20 to 120 for each GC-MS separation into a row vector. All of the sample row vectors are incorporated into a matrix where each row is a sample vector. This matrix is piecewise aligned and reduced by ANOVA feature selection. Application of the preprocessing steps (retention time alignment and feature selection) to all mass channels collected during the chromatographic separation allows considerably more selective chemical information to be incorporated in the PCA classification, and is the primary novelty of the report. This methodology is objective and requires no knowledge of the specific analytes of interest, as in selective ion monitoring (SIM), and does not restrict the mass spectral data used, as in both SIM and total ion current (TIC) methods. Significantly, the methodology allows for the classification of data with low resolution in the chromatographic dimension because of the added selectivity from the complete mass spectral dimension. This allows for the successful classification of data over significantly decreased chromatographic separation times, since high-speed separations can be employed. The methodology is demonstrated through the analysis of a set of four differing gasoline samples that serve as model complex samples. For comparison, the gasoline samples are analyzed by GC-MS over both 10-min and 10-s separation times. The successfully classified 10-min GC-MS TIC data served as the benchmark analysis to compare to the 10-s data. When only alignment and feature selection was applied to the 10-s gasoline separations using GC-MS TIC data, PCA failed. PCA was successful for 10-s gasoline separations when the methodology was applied with all the m/z information. With ANOVA feature selection, chromatographic regions with Fisher ratios greater than 1500 were retained in a new matrix and subjected to PCA yielding successful classification for the 10-s separations. 相似文献
8.
Thevis M Geyer H Mareck U Sigmund G Henke J Henke L Schänzer W 《Analytical and bioanalytical chemistry》2007,388(7):1539-1543
Manipulation of urine sampling in sports drug testing is considered a violation of anti-doping rules and is consequently sanctioned
by regulatory authorities. In 2003, three identical urine specimens were provided by three different athletes, and the identity
of all urine samples was detected and substantiated using numerous analytical strategies including gas chromatography–mass
spectrometry with steroid and metabolite profiling, gas chromatography–nitrogen/phosphorus detector analysis, high-performance
liquid chromatography–UV fingerprinting, and DNA-STR (short tandem repeat) analysis. None of the respective athletes was the
donor of the urine provided for doping analysis, which proved to be a urine sample collected from other unidentified individual(s).
Samples were considered suspicious based on identical steroid profiles, one of the most important parameters for specimen
individualization in sports drug testing. A database containing 14,224 urinary steroid profiles of athletes was screened for
specific values of 4 characteristic parameters (ratios of testosterone/epitestosterone, androsterone/etiocholanolone, androsterone/testosterone,
and 5α-androstane-3α,17β-diol/5β-androstane-3α,17β-diol) and only the three suspicious samples matched all criteria. Further
metabolite profiling regarding indicated medications and high-performance liquid chromatography–UV fingerprinting substantiated
the assumption of manipulation. DNA-STR analyses unequivocally confirmed that the 3 urine samples were from the same individual
and not from the athletes who provided DNA from either buccal cell material or blood specimens. This supportive evidence led
to punishment of all three athletes according to the rules of the World Anti-Doping Agency. Application of a new multidisciplinary
strategy employing common and new doping control assays enables the detection of urine substitution in sports drug testing.
Figure Identical GC-MS/NPD profiles of three urine specimens collected from three different individuals for doping control purposes 相似文献
9.
Eva Gorrochategui Josefina Casas Cinta Porte Sílvia Lacorte Romà Tauler 《Analytica chimica acta》2015
A lipidomic study was developed in a human placental choriocarcinoma cell line (JEG-3) exposed to tributyltin (TBT) and to a mixture of perfluorinated chemicals (PFCs). The method was based on the application of multivariate curve resolution-alternating least squares (MCR-ALS) to data sets obtained by ultra-high performance liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC–TOF-MS) using an untargeted approach. Lipids from exposed JEG-3 cells were solid–liquid extracted and analyzed by UHPLC–TOF-MS in full scan mode, together with control samples. Raw UHPLC–TOF-MS data of the different cell samples were subdivided into 20 distinct chromatographic windows and each window was further organized in a column-wise augmented data matrix, where data from every sample was in an individual data matrix. Then, the 20 new augmented data matrices were modeled by MCR-ALS. A total number of 86 components were resolved and a statistical comparative study of their elution profiles showed distinct responses for the lipids of exposed versus control cells, evidencing a lipidome disruption attributed to the presence of the xenobiotics. Results from one-way ANOVA followed by a multiple comparisons test and from discriminant partial least squares (PLS-DA) analysis were compared as usual strategies for the determination of potential biomarkers. Identification of 24 out of the 33 proposed biomarkers contributed to the better understanding of the effects of PFCs and TBT in the lipidome of human placental cells. Overall, this study proposes an innovative untargeted LC–MS MCR-ALS approach valid for -omic sciences such as lipidomics. 相似文献
10.
Davy Guillarme Cristina Casetta Carlo Bicchi Jean-Luc Veuthey 《Journal of chromatography. A》2010,1217(44):6882-6890
The analysis of polyphenols in tea extracts is important due to their potential health benefits. Therefore, efficient and high throughput analytical methods have been developed for the separation of seven predominant polyphenols, also known as catechin derivatives, present in tea extracts. Columns packed with sub-2-μm particles operating at elevated pressure (UHPLC strategy) were selected to improve chromatographic performance. The potential of UHPLC–UV was demonstrated with baseline resolution of all standard catechins in only 30 s using a 50-mm column packed with 1.7-μm particles. When dealing with real samples such as tea extracts, however, longer columns of up to 150 mm in length were employed to enhance the separation of catechin derivatives and other constituents within the tea samples while maintaining an acceptable analysis time. Two strategies based on 2-D experiments were proposed to clearly identify catechins. Firstly, a liquid–liquid extraction procedure was added prior to the UHPLC–UV analysis to decrease the complexity of the sample. Secondly, UHPLC was coupled to ESI-MS/MS to attain sufficient sensitivity and selectivity between catechin derivatives and other constituents of tea extract. These two strategies were found extremely promising as a clear discrimination of catechins from the matrix could be attained. 相似文献
11.
Drummer OH 《Analytical and bioanalytical chemistry》2007,388(7):1495-1503
The application of analytical techniques in postmortem toxicology is often more difficult than in other forms of forensic
toxicology owing to the variable and often degraded nature of the specimens and the diverse range of specimens available for
analysis. Consequently, analysts must ensure that all methods are fully validated for the particular postmortem specimen(s)
used. Collection of specimens must be standardized to minimize site-to-site variability and should if available include a
peripheral blood sample and at least one other specimen. Urine and vitreous humor are good specimens to complement blood.
In some circumstances solid tissues such as liver are recommended as well as gastric contents. Substance-screening techniques
are the most important element since they will determine the range of substances that were targeted in the investigation and
provide initial indication of the possible role of substances in the death. While immunoassay techniques are still commonly
used for the most common drugs-of-abuse, chromatographic screening methods are required for general unknown testing. These
are still predominately gas chromatography (GC) based using nitrogen/phosphorous detection and/or mass spectrometry (MS) detection,
although some laboratories are now using time-of-flight MS or liquid chromatography (LC)–MS(MS) to cover a sometimes more
limited range of substances. It is recommended that laboratories include a second chromatographic method to provide coverage
of acidic and other substances not readily covered by a GC-based screen when extracts do not include all physiochemical types.
This may include a gradient high-performance liquid chromatography (HPLC) photodiode array method, or better LC-MS(MS). Substance-specific
techniques (e.g., benzodiazepines, opiates) providing a second form of identification (confirmation) are now divided between
GC-MS(MS) and LC-MS(MS) procedures. LC-MS(MS) has taken over from many methods for the more polar compounds previously used
in HPLC or in GC methods requiring derivatization. Analysts using LC-MS will need to obtain clean extracts to avoid poor and
variable sensitivity caused by background suppression of the signal. Isolation techniques in postmortem toxicology tend to
favor liquid extraction; however solid-phase extraction and solid-phase microextraction methods are available for many analytes. 相似文献
12.
Paglia G Hrafnsdóttir S Magnúsdóttir M Fleming RM Thorlacius S Palsson BØ Thiele I 《Analytical and bioanalytical chemistry》2012,402(3):1183-1198
Here we present an ultra-performance liquid chromatography–mass spectrometry (UPLC–MS) method for extracellular measurements
of known and unexpected metabolites in parallel. The method was developed by testing 86 metabolites, including amino acids,
organic acids, sugars, purines, pyrimidines, vitamins, and nucleosides, that can be resolved by combining chromatographic
and m/z dimensions. Subsequently, a targeted quantitative method was developed for 80 metabolites. The presented method combines
a UPLC approach using hydrophilic interaction liquid chromatography (HILIC) and MS detection achieved by a hybrid quadrupole–time
of flight (Q–ToF) mass spectrometer. The optimal setup was achieved by evaluating reproducibility and repeatability of the
analytical platforms using pooled quality control samples to minimize the drift in instrumental performance over time. Then,
the method was validated by analyzing extracellular metabolites from acute lymphoblastic leukemia cell lines (MOLT-4 and CCRF-CEM)
treated with direct (A-769662) and indirect (AICAR) AMP activated kinase (AMPK) activators, monitoring uptake and secretion
of the targeted compound over time. This analysis pointed towards a perturbed purine and pyrimidine catabolism upon AICAR
treatment. Our data suggest that the method presented can be used for qualitative and quantitative analysis of extracellular
metabolites and it is suitable for routine applications such as in vitro drug screening. 相似文献
13.
A new electro solid-phase microextraction (El-SPME) technique using homemade pencil-lead fibers has been developed as an effective
means of selective extraction of methamphetamine before analysis by gas chromatography (GC) and gas chromatography–mass spectrometry
(GC–MS). The methamphetamine was extracted by use of a laboratory-made El-SPME cell with three electrodes—the pencil-lead
SPME fiber, Ag/AgCl, and platinum as working, reference, and auxiliary electrodes, respectively. A negative potential was
applied to the homemade pencil-lead fiber during extraction. Experimental conditions, for example type of pencil-lead fiber,
conditions for modification of the fiber, extraction time, applied potential, pH, and gas chromatographic conditions were
optimized. Methamphetamine was identified by GC–MS. Screening of the extracted compounds showed that the proposed El-SPME
technique is much more selective than direct SPME using a commercially available polyacrylate fiber. Under the optimum conditions
the calibration plot for the compound was linear in the range 50–3,200 ng mL−1 and the detection limit was 34 ng mL−1. 相似文献
14.
González-Fernández M García-Barrera T Gómez-Ariza JL 《Analytical and bioanalytical chemistry》2011,401(9):2779-2783
This paper reports the identification and quantification of superoxide dismutase in the liver of Mus musculus and Mus spretus mice using a metallomics analytical approach. The approach consisted of using orthogonal chromatographic systems coupled
to ICP–MS and UV detectors. Size-exclusion fractionation of the cytosolic extracts was followed by anion-exchange chromatographic
separation of Cu- and Zn-containing species. After purification then tryptic digestion, Cu- and Zn-containing superoxide dismutase
was identified by nESI-QqTOF. The MS–MS spectra of doubly charged peptides, with the Mascot searching engine, were used to
obtain the sequence of the protein. 相似文献
15.
Lucie Nováková Marco Rentsch Alexandre Grand-Guillaume Perrenoud Raul Nicoli Martial Saugy Jean‑Luc Veuthey Davy Guillarme 《Analytica chimica acta》2015
The potential and applicability of UHPSFC–MS/MS for anti-doping screening in urine samples were tested for the first time. For this purpose, a group of 110 doping agents with diverse physicochemical properties was analyzed using two separation techniques, namely UHPLC–MS/MS and UHPSFC–MS/MS in both ESI+ and ESI− modes. The two approaches were compared in terms of selectivity, sensitivity, linearity and matrix effects. As expected, very diverse retentions and selectivities were obtained in UHPLC and UHPSFC, proving a good complementarity of these analytical strategies. In both conditions, acceptable peak shapes and MS detection capabilities were obtained within 7 min analysis time, enabling the application of these two methods for screening purposes. Method sensitivity was found comparable for 46% of tested compounds, while higher sensitivity was observed for 21% of tested compounds in UHPLC–MS/MS and for 32% in UHPSFC–MS/MS. The latter demonstrated a lower susceptibility to matrix effects, which were mostly observed as signal suppression. In the case of UHPLC–MS/MS, more serious matrix effects were observed, leading typically to signal enhancement and the matrix effect was also concentration dependent, i.e., more significant matrix effects occurred at the lowest concentrations. 相似文献
16.
María Ibáñez Carlos GuerreroJuan V. Sancho Félix Hernández 《Journal of chromatography. A》2009,1216(12):2529-2539
The potential of ultra-high-pressure liquid chromatography (UHPLC) coupled to hybrid quadrupole time-of-flight mass spectrometry (QTOF–MS) for the screening and confirmation of antibiotics in water samples is illustrated in this paper. UHPLC presents several advantages over conventional liquid chromatography as it generates narrow peaks (increasing peak height and improving sensitivity) and reduces chromatographic runs. Regarding QTOF–MS, its increased mass resolution, high sensitivity in full-spectrum acquisition mode and mass accuracy, in both MS and MS/MS modes, make this technique ideal for the detection and reliable confirmation of organic contaminants in environmental samples. After a solid-phase extraction using Oasis HLB cartridges, UHPLC–QTOF–MS has been applied in this work to several types of water samples (surface water and influent and effluent wastewaters). Several antibiotics were found in the samples, such as ofloxacin, ciprofloxacin, clarythromycin or erythromycin, among others. Moreover, the full spectrum data provided by TOF–MS acquisition has enabled searching for many other pharmaceuticals that could be present in the samples in a “post-target” way. This approach has allowed the detection and confirmation of paracetamol, omeprazole and codeine, among others. UPLC–QTOF–MS has been shown as an attractive and efficient hyphenated technique for the rapid detection and confirmation of pharmaceuticals in water with very little sample handling. 相似文献
17.
Blagoj Mitrevski Paul Wynne Philip J. Marriott 《Analytical and bioanalytical chemistry》2011,401(8):2361-2371
Multidimensional gas chromatography (MDGC), and especially its latest incarnation—comprehensive two-dimensional gas chromatography
(GC × GC)—have proved advantageous over and above classic one-dimensional gas chromatography (1D GC) in many areas of analysis
by offering improved peak capacity, often enhanced sensitivity and, especially in the case of GC × GC, the unique feature
of ‘structured’ chromatograms. This article reviews recent advances in MDGC and GC × GC in drug analysis with special focus
on ecstasy, heroin and cocaine profiling. Although 1D GC is still the method of choice for drug profiling in most laboratories
because of its simplicity and instrument availability, GC × GC is a tempting proposition for this purpose because of its ability
to generate a higher net information content. Effluent refocusing due to the modulation (compression) process, combined with
the separation on two ‘orthogonal’ columns, results in more components being well resolved and therefore being analytically
and statistically useful to the profile. The spread of the components in the two-dimensional plots is strongly dependent on
the extent of retention ‘orthogonality’ (i.e. the extent to which the two phases possess different or independent retention
mechanisms towards sample constituents) between the two columns. The benefits of ‘information-driven’ drug profiling, where
more points of reference are usually required for sample differentiation, are discussed. In addition, several limitations
in application of MDGC in drug profiling, including data acquisition rate, column temperature limit, column phase orthogonality
and chiral separation, are considered and discussed. Although the review focuses on the articles published in the last decade,
a brief chronological preview of the profiling methods used throughout the last three decades is given. 相似文献
18.
Qing LS Xue Y Deng WL Liao X Xu XM Li BG Liu YM 《Analytical and bioanalytical chemistry》2011,399(3):1223-1231
The chemical composition of herbal medicines is very complex, and their therapeutic effects are determined by multi-components
with sophisticated synergistic and/or suppressive actions. Therefore, quality control of herbal medicines has been a formidable
challenge. In this work, we describe a fast analytical method that can be used for quality assessment of herbal medicines.
The method is based on ligand fishing using human-serum-albumin-functionalized magnetic nanoparticles (HSA-MNPs) and mass
spectrometry. To demonstrate the applicability of the proposed method, eight samples of Dioscorea panthaica were analyzed. The sampled plants were of both wild and cultivated origins. They grew at different geographical locations
and were harvested at different times. The ligands bound to HSA-MNPs were isolated from the plant extracts and detected by
using direct infusion electrospray ionization mass spectrometry (DI–ESI–MS). Chemical identity has been confirmed for five
of the ligands isolated. From more than 15 peaks in the ESI–MS spectrum, 11 common peaks were selected for calculating the
correlation coefficient and cosine ratio. The values of correlation coefficient and cosine ratio were >0.9824 and >0.9988,
respectively, for all the samples tested. The results indicated a high level of similarity among the eight D. panthaica samples. Compared with chromatographic fingerprint analysis, the proposed HSA-MNP-based DI–ESI–MS/MS approach was not only
fast and easy to carry out but also biological-activity-oriented, promising a more effective data interpretation and thus
reliable assessment conclusions. 相似文献
19.
Marie-Claude Djidja Emmanuelle Claude Marten F. Snel Simona Francese Peter Scriven Vikki Carolan Malcolm R. Clench 《Analytical and bioanalytical chemistry》2010,397(2):587-601
The development of tissue micro-array (TMA) technologies provides insights into high-throughput analysis of proteomics patterns
from a large number of archived tumour samples. In the work reported here, matrix-assisted laser desorption/ionisation–ion
mobility separation–mass spectrometry (MALDI–IMS–MS) profiling and imaging methodology has been used to visualise the distribution
of several peptides and identify them directly from TMA sections after on-tissue tryptic digestion. A novel approach that
combines MALDI–IMS–MSI and principal component analysis–discriminant analysis (PCA–DA) is described, which has the aim of
generating tumour classification models based on protein profile patterns. The molecular classification models obtained by
PCA–DA have been validated by applying the same statistical analysis to other tissue cores and patient samples. The ability
to correlate proteomic information obtained from samples with known and/or unknown clinical outcome by statistical analysis
is of great importance, since it may lead to a better understanding of tumour progression and aggressiveness and hence improve
diagnosis, prognosis as well as therapeutic treatments. The selectivity, robustness and current limitations of the methodology
are discussed. 相似文献
20.
The application of multi-way parallel factor analysis (PARAFAC2) is described for the classification of different kinds of petroleum oils using GC-MS. Oils were subjected to controlled weathering for 2, 7 and 15 days and PARAFAC2 was applied to the three-way GC-MS data set (MSxGCxsample). The classification patterns visualized in scores plots and it was shown that fitting multi-way PARAFAC2 model to the natural three-way structure of GC-MS data can lead to the successful classification of weathered oils. The shift of chromatographic peaks was tackled using the specific structure of the PARAFAC2 model. A new preprocessing of spectra followed by a novel use of analysis of variance (ANOVA)-least significant difference (LSD) variable selection method were proposed as a supervised pattern recognition tool to improve classification among the highly similar diesel oils. This lead to the identification of diagnostic compounds in the studied diesel oil samples. 相似文献