共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
Popot MA Woolfitt AR Garcia P Tabet JC 《Analytical and bioanalytical chemistry》2008,390(7):1843-1852
The insulin-like-growth factor (IGF-I) peptide is considered to be the main indirect marker for growth hormone administration
(GH) in a horse. Further to a previous investigation on measurement of IGF-I in plasma samples by mass spectrometry, this
study focuses on quantitative and qualitative analysis of intact IGF-I in horse plasma. First, protein-transposing software
has been developed for IGF-I to facilitate its quantification by HPLC–electrospray–ion-trap mass spectrometry. Second, product-ion
scan experiments on IGF-I have been conducted on standard samples, non-fortified equine plasma samples, fortified plasma samples,
and equine GH post-administration samples. This “top-down” approach method enables characterisation of fragment ions corresponding
to the carboxy terminal end, which can be useful for the confirmation of the presence of IGF-I in plasma samples.
Figure Structure of IGF-I and amino acid sequences of IGF-I and R3 IGF-I. Deconvolution mass spectra of the IGF-I and R3 IGF-I mixture 相似文献
3.
Rudolf Tuckermann Ljiljana Puskar Mahta Zavabeti Ryo Sekine Don McNaughton 《Analytical and bioanalytical chemistry》2009,394(5):1433-1441
An experimental apparatus combining Raman spectroscopy with acoustic levitation, Raman acoustic levitation spectroscopy (RALS),
is investigated in the field of physical and chemical analytics. Whereas acoustic levitation enables the contactless handling
of microsized samples, Raman spectroscopy offers the advantage of a noninvasive method without complex sample preparation.
After carrying out some systematic tests to probe the sensitivity of the technique to drop size, shape, and position, RALS
has been successfully applied in monitoring sample dilution and preconcentration, evaporation, crystallization, an acid–base
reaction, and analytes in a surface-enhanced Raman spectroscopy colloidal suspension.
Figure We have systematically investigated the analytical potential of Raman spectroscopy of samples in acoustically levitated drops. 相似文献
4.
Emily O’Neill Danielle Harrington John Allison 《Analytical and bioanalytical chemistry》2009,393(8):2029-2038
Monitoring of cell cultures in microbioreactors is a crucial task in cell bioassays and toxicological tests. In this work
a novel tool based on a miniaturized sensor array fabricated using low-temperature cofired ceramics (LTCC) technology is presented.
The developed device is applied to the monitoring of cell-culture media change, detection of the growth of various species,
and in toxicological studies performed with the use of cells. Noninvasive monitoring performed with the LTCC microelectrode
array can be applied for future cell-engineering purposes.
Figure Microelectrode array for monitoring of cell cultures 相似文献
5.
Tuulia Hyötyläinen 《Analytical and bioanalytical chemistry》2009,394(3):743-758
Sample preparation before chromatographic separation is the most time-consuming and error-prone part of the analytical procedure.
Therefore, selecting and optimizing an appropriate sample preparation scheme is a key factor in the final success of the analysis,
and the judicious choice of an appropriate procedure greatly influences the reliability and accuracy of a given analysis.
The main objective of this review is to critically evaluate the applicability, disadvantages, and advantages of various sample
preparation techniques. Particular emphasis is placed on extraction techniques suitable for both liquid and solid samples.
Figure Miniaturised extraction techniques allow sensitive analysis of also small sample volumes. 相似文献
6.
Liu Yang Shunjun Xu Chunjin Liu Zhijun Su 《Analytical and bioanalytical chemistry》2009,395(5):1441-1451
Ginsenoside Re is one of the major the bioactive triterpene saponins in ginseng root, a well-known adaptogen in traditional
Chinese medicine. It is believed that the lead compound may be further developed into a promising new drug for preventing
hypertension and cardiovascular disease. To better understand the pharmacological activities of the component, an investigation
of its in vivo metabolism was necessary. In the present study, a high-performance liquid chromatography coupled with electrospray
ionization and quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-TOF-MS/MS) has been applied to discover and identify
the metabolites of ginsenoside Re in rat urine following intravenous and oral administration of the component, respectively.
The rat urine samples were collected and pretreated through C18 solid-phase extraction cartridges prior to analysis. Negative electrospray ionization mass spectrometry was used to discern
ginsenoside Re and its possible metabolites in urine samples. The metabolites were identified and tentatively characterized
by means of comparing molecular mass, retention time, and fragmentation pattern of the analytes with those of the parent compound,
ginsenoside Re. As a result, eleven and nine metabolites together with Re were detected and identified in rat urine collected
after intravenous and oral administration, respectively. A possible metabolic pathway of ginsenoside Re was also investigated
and proposed. Oxidation and deglycosylation were found to be the major metabolic processes of the constituent in rat.
相似文献
7.
Marco Frasconi Monica Mazzarino Francesco Botrè Franco Mazzei 《Analytical and bioanalytical chemistry》2009,394(8):2151-2159
In this paper, we present a surface-plasmon-resonance-based immunosensor for the real-time detection of cortisol and cortisone
levels in urine and saliva samples. The method proposed here is simple, rapid, economic, sensitive, robust, and reproducible
thanks also to the special features of the polycarboxylate-hydrogel-based coatings used for the antibody immobilization. The
sensor surface displays a high level of stability during repeated regeneration and affinity reaction cycles. The immunosensor
shows high specificity for cortisol and cortisone; furthermore, no significant interferences from other steroids with a similar
chemical structure have been observed. The suitability of the hydrogel coating for the prevention of nonspecific binding is
also investigated. A good correlation is noticed between the results obtained by the proposed method and the reference liquid
chromatography/tandem mass spectrometry method for the analysis of cortisol and cortisone in urine and saliva samples. Standard
curves for the detection of cortisol and cortisone in saliva and urine are characterized by a detection limit less than 10 μg l−1, sufficiently sensitive for both clinical and forensic use.
Application of a newly developed SPR immunosensor for the measurement of cortisol in anti-doping analysis 相似文献
8.
Veronica M. T. Lattanzio Michele Solfrizzo Angelo Visconti 《Analytical and bioanalytical chemistry》2009,395(5):1325-1334
The selective enzymatic deacetylation of T-2 toxin to give HT-2 toxin has been investigated in aqueous crude extracts of different
cereals and exploited to develop an analytical method for the determination of the sum of T-2 and HT-2 toxins. The method
has been validated for the analysis of total T-2 and HT-2 toxins in maize, wheat, and oats, showing recoveries from 72 to
97% for maize, from 67 to 84% for wheat, and from 61% to 87% for oats, at spiking levels of 20–400 μg/kg, with relative standard
deviation lower than 10%. Liquid chromatography-tandem mass spectrometry was used for quantitative toxin determination. The
potential biological role of this enzymatic conversion and its perspectives for application in the development of antibody-based
analytical techniques are discussed.
相似文献
9.
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
10.
Hye Kyeong Min Gu Kong Myeong Hee Moon 《Analytical and bioanalytical chemistry》2010,396(3):1273-1280
Analysis was performed on four different categories of phospholipids (phosphatidylserine (PS), phosphatidylinositol (PI),
phosphatidylglycerol (PG), and phosphatidic acid (PA)) from urine in patients with breast cancer. This quantitative analysis
was conducted using nanoflow liquid chromatography–electrospray ionization–tandem mass spectrometry (nLC-ESI-MS-MS). This
study shows the profiling of the phospholipids (PLs) that can be identified by the negative ion mode of MS. A previous study
(Kim et al. Anal. Bioanal. Chem. 393:1649, 21) focused on only two PL classes: phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) and were identified by positive
ion mode. PLs were extracted by lyophilization of 1 mL of urine from both healthy normal females and breast cancer patients
before and after surgery. Separation of PLs was performed by nLC followed by structural identification of PLs using data-dependent
collision-induced dissociation. A total of 34 urinary PL molecules (12 PSs, 12 PIs, four PGs, and six PAs) were quantitatively
examined. Among the four PL categories examined in this study, most PL classes showed an increase in the total amounts in
the cancer patients, yet PIs exhibited some decreases. The present study suggests that the lipid composition found in the
urine of breast cancer patients can be utilized for the possible development of disease markers, when the analysis is performed
with negative ion mode of nLC-ESI-MS-MS.
相似文献
11.
C. R. Dockery A. R. Stefan A. A. Nieuwland S. N. Roberson B. M. Baguley J. E. Hendrix S. L. Morgan 《Analytical and bioanalytical chemistry》2009,394(8):2095-2103
Systematic designed experiments were employed to find the optimum conditions for extraction of direct, reactive, and vat dyes
from cotton fibers prior to forensic characterization. Automated microextractions were coupled with measurements of extraction
efficiencies on a microplate reader UV–visible spectrophotometer to enable rapid screening of extraction efficiency as a function
of solvent composition. Solvent extraction conditions were also developed to be compatible with subsequent forensic characterization
of extracted dyes by capillary electrophoresis with UV–visible diode array detection. The capillary electrophoresis electrolyte
successfully used in this work consists of 5 mM ammonium acetate in 40:60 acetonitrile–water at pH 9.3, with the addition
of sodium dithionite reducing agent to facilitate analysis of vat dyes. The ultimate goal of these research efforts is enhanced
discrimination of trace fiber evidence by analysis of extracted dyes.
Figure Fitted absorbance response surface for extraction of a direct dye, C. I. yellow 58, using a ternary solvent system. 相似文献
12.
Bercaru O Ulberth F Emons H Vandecasteele C 《Analytical and bioanalytical chemistry》2006,384(5):1207-1213
The effect of dissolved humic acids on the recovery of PAHs from water samples has been investigated using a commercially
available humic acid preparation as colloid model and a mixture containing the 16 EPA PAHs. The presence of humic acid reduced
the extraction efficiency down to between 10 and 75%. An analytical protocol was therefore developed for the accurate determination
of PAHs in the presence of humic acids based on isotope dilution mass spectrometry. The procedure compensates for losses due
to sorption of PAHs and can be used for the determination of the total PAH concentration in water, i.e. dissolved PAHs plus
PAHs adsorbed on colloids. To obtain reliable estimates it is essential to allow a certain time for equilibration between
the isotope spike and the aqueous matrix which may vary between 5 and 24 h, in correlation with the water solubility of PAHs.
The protocol allows one to recover the 16 PAHs studied at 94 to 105%. The expanded uncertainty of the measurements was 5–7%
for all PAHs. Liquid–liquid extraction and solid-phase extraction in combination with the developed isotope dilution protocol
performed equally well for the quantification of PAHs from water samples rich in colloidal material.
相似文献
13.
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
14.
n-Butyl benzyl phthalate (BBP) is an endocrine-disrupting chemical. A bacterium species capable of using BBP as the sole source
of carbon and energy was isolated from mangrove sediment. Effects of BBP concentration, pH, temperature, and salinity on BBP
biodegradation were studied. The optimum pH, temperature, and salinity for the BBP biodegradation were 7.0, 37°C, and 15 g L−1, respectively. BBP was completely degraded within 6 days under optimum conditions, and the biodegradation of BBP could be
fitted to a first-order kinetic model. The major metabolites of BBP biodegradation were identified as mono-butyl phthalate,
mono-benzyl phthalate, phthalic acid, and benzoic acid by using high-performance liquid chromatography and gas chromatography–mass
spectrometry. A preliminary metabolic pathway was proposed for the biodegradation of BBP.
相似文献
15.
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
16.
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
17.
A rapid, specific, and sensitive method has been developed using molecularly imprinted polymers (MIPs) as solid-phase extraction
sorbents for extraction of trace tetracycline antibiotics (TCs) in foodstuffs. MIPs were prepared by precipitation polymerization
using tetracycline as the template. Under the optimal condition, the imprinting factors for MIPs were 4.1 (oxytetracycline),
7.0 (tetracycline), 7.4 (chlortetracycline), 7.7 (doxycycline), respectively. Furthermore, the performance of MIPs as solid-phase
extraction sorbents was evaluated and high extraction efficiency of molecularly imprinted solid-phase extraction (MISPE) procedure
was demonstrated. Compared with commercial sorbents, MISPE gave a better cleanup efficiency than C18 cartridge and a higher
recovery than Oasis HLB cartridge. Finally, the method of liquid chromatography–tandem mass spectrometry coupled with molecular-imprinted
solid-phase extraction was validated in real samples including lobster, duck, honey, and egg. The spiked recoveries of TCs
ranged from 94.51% to 103.0%. The limits of detection were in the range of 0.1–0.3 μg kg−1.
Chromatograms obtained by direct injection of the spiked egg extracts (5 × 10-3 mmol L−1) and purification with MISPE 相似文献
18.
Application of surface chemical analysis tools for characterization of nanoparticles 总被引:1,自引:1,他引:0
D. R. Baer D. J. Gaspar P. Nachimuthu S. D. Techane D. G. Castner 《Analytical and bioanalytical chemistry》2010,396(3):983-1002
The important role that surface chemical analysis methods can and should play in the characterization of nanoparticles is
described. The types of information that can be obtained from analysis of nanoparticles using Auger electron spectroscopy
(AES), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary-ion mass spectrometry (TOF-SIMS), low-energy ion scattering
(LEIS), and scanning-probe microscopy (SPM), including scanning tunneling microscopy (STM) and atomic force microscopy (AFM),
are briefly summarized. Examples describing the characterization of engineered nanoparticles are provided. Specific analysis
considerations and issues associated with using surface-analysis methods for the characterization of nanoparticles are discussed
and summarized, with the impact that shape instability, environmentally induced changes, deliberate and accidental coating,
etc., have on nanoparticle properties.
相似文献
19.
Christian Zwiener Thomas Glauner Jochen Sturm Michael W?rner Fritz H. Frimmel 《Analytical and bioanalytical chemistry》2009,395(6):1885-1892
Potentiostatic-controlled electrochemical reduction of iomeprol was used to deiodinate iomeprol (IMP), a representative of
the iodinated X-ray contrast media. The reduction process was followed by product analysis with liquid chromatography-electrospray
ionization-tandem mass spectrometry and ion chromatography-inductively coupled plasma-mass spectrometry. The identification
is mainly based on the interpretation of the mass fragmentation. The product analysis showed a rather selective deiodination
process with the successive occurrence of IMP-I, IMP-2I, IMP-3I, and a transformation product (TP), respectively. The TP was
formed from IMP-3I by a further cleavage of an amide bond and release of a (C = O)CHOH group from the side chain of IMP. The
iodine mass balance on the basis of IMP and iodide showed a gap of about 26% at the beginning of the electrolysis process
which could be completely closed by taking the intermediates IMP-I and IMP-2I into consideration. This means that the major
intermediates and the TPs were considered and that the reduction process is a rather selective one to remove organically bound
iodine from X-ray contrast media. An attractive application area would be the electrochemical deiodination of X-ray contrast
media in urine of patients or hospital effluents.
相似文献
20.
Hongjuan Dong Jasmin Kemptner Martina Marchetti-Deschmann Christian Peter Kubicek Günter Allmaier 《Analytical and bioanalytical chemistry》2009,395(5):1373-1383
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) has been proved to be a powerful
tool for the identification and characterization of microorganisms based on their surface peptide/protein pattern. Because
of the complexity of microorganisms, there are no standardized protocols to acquire reproducible peptide/protein profiles
for a broad range of microorganisms and for fungi in particular. Small variations during MALDI MS sample preparation affect
the quality of mass spectra quite often. In this study, we were aiming to develop a sample preparation method for the analysis
of colored, a quite often observed phenomenon, and mycotoxin-producing Fusarium conidia spores using MALDI–TOF MS. Different washing solvent systems for light- and deep-colored (from slightly orange to
red-brown) conidia spores and connected sample deposition techniques were evaluated based on MS reproducibility and number
and intensities of peaks. As a method of choice for generation of reproducible and characteristic MALDI–TOF mass spectra,
the use of a washing process for colored Fusarium conidia spores with acetonitrile/0.5% formic acid (7/3) was found and subsequently combined with two-layer volume technique
(spores/matrix (ferulic acid) solution was deposited onto a MALDI target, and after solvent evaporation, a second matrix layer
was deposited). With the application of this sample preparation method, for deep-colored Fusarium species, 19 abundant molecular ions in the m/z range 2,000–10,000 were always detected with an S/N ratio of 3:1 or better. Finally this optimized sample preparation for
the first time provided mass spectrometric fingerprints of strongly colored Fusarium conidia spores resulting in the possibility of differentiation of such spores at the species level.
相似文献