共查询到20条相似文献,搜索用时 31 毫秒
1.
Fabien Lamoureux Jean-michel Gaulier François-Ludovic Sauvage Magali Mercerolle Christine Vallejo Gérard Lachâtre 《Analytical and bioanalytical chemistry》2009,394(7):1895-1901
The detection of ethyl-β-d-6-glucuronide (EtG), a stable phase II metabolite of ethanol, is of interest in both clinical and forensic contexts with
the aim of monitoring alcohol abuse. We present a liquid chromatography-electrospray ionisation-tandem mass spectrometry method
for the detection and quantification of EtG in hair. Thirty milligrams of washed and cut hair were cleaned up using solid-phase
extraction graphite cartridges. Separation was then performed using an Uptisphere-3SI column, and the detection was operated
in the negative mode. After validation, the method was applied to hair samples taken from four fatalities (F) with documented
excessive drinking habits, 12 heavy drinkers (HD) and seven social drinkers (SD). The method exhibits limits of detection
and quantification of 4 and 10 pg/mg, respectively. Intra- and inter-assay standard deviation and relative bias were less
than 20% over the calibrating range (10 to 3,000 pg/mg). EtG hair concentrations in SD were <10 pg/mg and >50 pg/mg for F
and HD (range, 54 to 497 pg/mg). The present assay appears convenient to carry out owing to the very small quantity of hair
samples required to determine an effective heavy alcohol consumption (EtG hair concentration >50 pg/mg). 相似文献
2.
Maria Elena Albermann F. Musshoff B. Madea 《Analytical and bioanalytical chemistry》2010,396(7):2441-2447
Hair analysis has become a powerful tool for the detection of chronic and past drug consumption. For several years, it has
been possible to determine even the intake of ethanol in hair samples by detecting the ethanol metabolites ethyl glucuronide
or fatty acid ethyl esters. Recently, new requirements were published for the use of EtG as an abstinence test (c
EtG < 7 pg/mg) as well as for heavy-drinking detection (c
EtG > 30 pg/mg). In order to perform abstinence tests, a sensitive LC-MS/MS procedure has been developed and fully validated
according to the guidelines of forensic toxicology. The nine-point calibration curve showed linearity over the range of concentrations
from 2–1,000 pg/mg. Detection and quantification limits were 1 and 4 pg/mg respectively. The intra- and inter-day precision
and accuracy were always better than 20%. The validated procedure has successfully been applied to perform abstinence tests
and to analyze hair samples from persons in withdrawal treatment. Concentrations between <LOQ and 400 pg/mg were determined.
In some cases, interfering peaks complicated the quantification to some extent. First results using varied chromatographic
conditions showed constituting results. However, modified chromatographic conditions help substantiate critical results, especially
if the determined EtG concentration is close to a cut-off value. 相似文献
3.
Albermann ME Musshoff F Aengenheister L Madea B 《Analytical and bioanalytical chemistry》2012,403(3):769-776
Ethyl glucuronide (EtG) analysis in hair is a suitable method for the retrospective determination of previous alcohol consumption.
According to the German guidelines, EtG abstinence is improbable at c
EtG > 7 pg/mg in the proximal 3 cm of scalp hair. The chromatography of the routinely used liquid chromatography-tandem mass
spectrometry procedure was optimized by replacing the stationary phase. To simplify sample preparation, two different mills
were tested, and an optimized grinding process was developed. The new method was successfully validated according to the guidelines
of the German Society of Toxicological and Forensic Chemistry. Despite a simple extraction procedure without any cleaning
steps, a very high sensitivity (limit of detection, 1.7 pg/mg; limit of quantitation, 2.3 pg/mg) could be achieved. Competitive
analysis showed significantly higher EtG concentrations in pulverized versus cut hair samples. The strong impact of sample
preparation on the determined EtG concentrations suggests the introduction of a standardized sample preparation method to
produce comparable results. 相似文献
4.
Iván álvarez Ana María Bermejo María Jesús Tabernero Purificación Fernández Pamela Cabarcos Patricia López 《Analytical and bioanalytical chemistry》2009,393(4):1345-1350
Alcohol is the most frequently abused “addictive substance” that causes serious social problems throughout the world; thus,
alcoholism is of particular interest in clinical and forensic medicine. Alcohol biomarkers are physiological indicators of
alcohol exposure or ingestion and may reflect the presence of an alcohol use disorder. The glucuronide conjugation is a minor
pathway of ethanol metabolism. Ethyl glucuronide (EtG) is a marker of recent alcohol consumption that detects alcohol use
reliably over a definite time period. The present paper describes a new method for the determination of EtG in hair. It is
based both in the microwave-assisted extraction (MAE), to extract the analyte from hair samples, and gas chromatography–mass
spectrometry (GC-MS), to identify and quantify the EtG in selected ion monitoring (SIM) mode. The method was applied to 15
hair samples from occasional alcohol users, obtaining positive results in all cases. It was fully validated, including a linear
range (0.3–10 ng/mg) and the main precision parameters. In summary, the use of microwave-assisted extraction turned out to
be a substantially simpler, faster, and a more sensitive procedure than any other conventional sample preparations. 相似文献
5.
F Granado-Lorencio C Herrero-Barbudo I Blanco-Navarro B Pérez-Sacristán 《Analytical and bioanalytical chemistry》2010,397(3):1389-1393
Our aim was to assess the suitability of ultra-high performance liquid chromatography (UHPLC) for the simultaneous determination
of biomarkers of vitamins A (retinol, retinyl esters), E (α- and γ-tocopherol), D (25-OH-vitamin D), and the major carotenoids
in human serum to be used in clinical practice. UHPLC analysis was performed on HSS T3 column (2.1 × 100 mm; 1.8 μm) using
gradient elution and UV–VIS detection. The system allows the simultaneous determination of retinol, retinyl palmitate, 25-OH-vitamin
D, α- and γ-tocopherol, lutein plus zeaxanthin, α-carotene, β-carotene, α- and β-cryptoxanthin and lycopene. The method showed
a good linearity over the physiological range with an adequate accuracy in samples from quality control programs. Suitability
of the method in clinical practice was tested by analyzing samples (n = 286) from patients. In conclusion, UHPLC constitutes a reliable approach for nutrient/biomarker profiling allowing the
rapid, simultaneous and low-cost determination of vitamins A, E, and D (including vitamers and ester forms) and the major
carotenoids in clinical practice. 相似文献
6.
H. Gnann C. Engelmann G. Skopp M. Winkler V. Auwärter S. Dresen N. Ferreirós F. M. Wurst W. Weinmann 《Analytical and bioanalytical chemistry》2010,396(7):2415-2423
Phosphatidylethanol (PEth) is an abnormal phospholipid carrying two fatty acid chains. It is only formed in the presence of
ethanol via the action of phospholipase D (PLD). Its use as a biomarker for alcohol consumption is currently under investigation.
Previous methods for the analysis of PEth included high-performance liquid chromatography (HPLC) coupled to an evaporative
light scattering detector (ELSD), which is unspecific for the different homologues—improved methods are now based on time
of flight mass spectrometry (TOF-MS) and tandem mass spectrometry (MS/MS). The intention of this work was to identify as many
homologues of PEth as possible. A screening procedure using multiple-reaction monitoring (MRM) for the identified homologues
has subsequently been established. For our investigations, autopsy blood samples collected from heavy drinkers were used.
Phosphatidylpropanol 16:0/18:1 (internal standard) was added to the blood samples prior to liquid–liquid extraction using
borate buffer (pH 9), 2-propanol and n-hexane. After evaporation, the samples were redissolved in the mobile phase and injected into the LC-MS/MS system. Compounds
were separated on a Luna Phenyl Hexyl column (50 mm × 2 mm, 3 μm) by gradient elution, using 2 mM ammonium acetate and methanol/acetone
(95/5; v/v). A total of 48 homologues of PEth could be identified by using precursor ion and enhanced product ion scans (EPI). 相似文献
7.
Morini L Colucci M Ruberto MG Groppi A 《Analytical and bioanalytical chemistry》2012,402(5):1865-1870
A liquid chromatography tandem mass spectrometry method for ethyl glucuronide (EtG) detection and quantification in nails
was developed and fully validated. Nails were extracted in 700 μL double-distilled water. EtG-d
5 was used as an internal standard. Reversed-phase separation was obtained with an isocratic mobile phase composed of 0.1%
formic acid and acetonitrile (99:1) for 10 min. Quantification was performed by multiple reaction monitoring of two transitions
per compound (EtG and internal standard). The assay was linear from 10 to 500 pg/mg. Validation parameters were studied at
three different quality control levels (10, 50, and 300 pg/mg). Intraday, interday, and total imprecision had a coefficient
of variation of less than 9.5%. Ion suppression and ion enhancement were negligible (less than 20%). No carryover was detected.
The method was applied to several real cases, among teetotalers, social drinkers, and heavy drinkers. A questionnaire, together
with the informed consent form, was given to all the participants in order to evaluate alcohol intake in the one month before
sample collection. Nail EtG levels in a social drinker were much higher than the concentrations of EtG in hair provided by
the same subject, thus suggesting potential high sensitivity in evaluating both chronic excessive alcohol consumption and
binge drinking habits. 相似文献
8.
Beyer J Vo TN Gerostamoulos D Drummer OH 《Analytical and bioanalytical chemistry》2011,400(1):189-196
Detection of the alcohol metabolites ethylglucuronide (EtG) and ethylsulfate (EtS) has become routine in many forensic laboratories
over the last few years. Most previously published methods using liquid chromatography coupled with electrospray tandem mass
spectrometry require a post-chromatographic addition of solvent and/or extensive sample preparation prior to analysis. The
aim of the study was to develop a simplified method. To 20 μL urine, internal standard containing EtG-d5 and EtS-d
5
was added and the mixture was treated with elution buffer internal standard. EtG and EtS were separated using a Shimadzu
Prominence high performance liquid chromatography (HPLC) system with a C18 separation column (Restek Ultra Aqueous C18, 4.6 × 150 mm,
5 μm), using isocratic elution with a mobile phase consisting of 10 mM ammonium acetate buffer pH 7 (total run time, 6 min).
The compounds were detected using an Applied Biosystems API 5000 liquid chromatography tandem mass spectrometry system (atmospheric
pressure chemical ionization, multiple-reaction monitoring mode). The method was fully validated according to international
guidelines. The assay was found to be selective for the compounds of interest. It was linear from 0.1 to 10 mg/L for all analytes
(R
2 > 0.99). Matrix effects studies showed the presence of a slight but consistent ion enhancement (n = 10 different urine samples) at low concentrations and no effects at higher concentrations. Accuracy data were between 0.75%
and 8.1% bias for EtG and between −5.0% and −11.3% bias for EtS. Precision data were between 4.3% and 6.9% relative standard
deviations (RSD) for EtG and between 6.0% and 7.5% RSD for EtS. No instability was observed after repeated freezing and thawing.
This fast, reliable, and accurate method enables the detection and quantification of alcohol metabolites in urine. The method
is easier to use and more sensitive than previously published methods. 相似文献
9.
Gareri J Appenzeller B Walasek P Koren G 《Analytical and bioanalytical chemistry》2011,400(1):183-188
Previous studies have indicated that the use of high-ethanol-content (>65%) hair-care products may elevate fatty acid ethyl
ester (FAEE) concentrations in hair. In this case series, nine individuals were identified by FAEE analysis to be chronic
alcohol abusers in the context of child-welfare substance abuse monitoring. Based on patient claims of moderate or no alcohol
consumption, the presence of ethanol in the patients’ hair-care regimens was investigated. Samples were additionally tested
for the presence of ethyl glucuronide (EtG). From a total of nine patients, 12 hair samples were submitted for analysis. Patient
histories were obtained as well as Material Safety Data Sheets (MSDS) listing hair-care product ethanol content. Hair samples
were pre-washed to remove external contamination and analyzed for FAEE and EtG by GC-MS. According to the Society of Hair
Testing consensus guidelines, FAEE levels exceeding 0.50 ng/mg and/or EtG levels exceeding 30 pg/mg indicate chronic excessive
alcohol consumption. Upon initial analysis, the nine samples exhibited positive FAEE findings ranging from 0.496 to 4.984 ng/mg.
MSDS review revealed the presence of ethanol from 10% to 95% by volume in at least one hair-care product used by each individual.
Results of the EtG analysis ranged from 1.9 to 23.5 pg/mg. These findings indicate that regular use of products with ethanol
content as low as 10% can impact FAEE results. EtG analysis should be used to confirm FAEE findings and appears to be unaffected
by hair-care products, likely due to alternative mechanisms of incorporation. 相似文献
10.
Mitochondrial NAD+-dependent isocitrate dehydrogenase (IDH3) catalyzes the allosterically regulated rate-limiting step of the tricarboxylic
acid cycle activated. In pigs, very little is known about this gene. Here, we cloned 1,346 bp full-length cDNA and 8,778 bp
genomic sequence of porcine γ subunit of IDH3 (IDH3γ). IDH3γ contains 12 exons separated by 11 introns. Real-time PCR revealed that IDH3γ mRNA were upregulated in backfat of Large White compared with Meishan and F1 hybrids, and most abundant in small intestine
via tissue distribution profile. A microsatellite (“GT” repeats) in second intron was found. The selected pigs were genotyped
at this microsatellite. The IDH3γ genotypes showed a significant effect on backfat thickness at thorax–waist (P < 0.05), backfat thickness at sixth to seventh thorax (P < 0.01), and average backfat thickness (P < 0.05). This site seemed to be significantly dominant in action (P < 0.05 for backfat thickness at sixth to seventh thorax, backfat thickness at thorax–waist, and average backfat thickness),
and allele B was associated with increase of thickness values of these traits. This locus is possibly considered as a marker
for adipose deposition traits. 相似文献
11.
Valiollah Babaeipour Seyed Abbas Shojaosadati Rasoul Khalilzadeh Nader Maghsoudi Amir Mohammad Farnoud 《Applied biochemistry and biotechnology》2010,160(8):2366-2376
Development of inexpensive and simple culture media and appropriate induction conditions are always favorable for industry.
In this research, chemical composition and stoichiometric data for γ-interferon production and recombinant Escherichia coli growth were used in order to achieve a simple medium and favorable induction conditions. To achieve this goal, the effects
of medium composition and induction conditions on the production of γ-interferon were investigated in batch culture of E. coli BL21 (DE3) [pET3a-ifnγ]. These conditions were considered as suitable conditions for the production of γ-interferon: 2.5× M9 medium, supplemented
with a mixture of amino acids (milligram per liter), including glutamic acid 215, aspartic acid 250, lysine 160, and phenylalanine
90, and induction at late-log phase (OD600 = 4.5). Under these conditions, dry cell weight of 6 ± 0.2 g/l and γ-interferon concentration of 2.15 ± 0.1 g/l were obtained.
Later, without changing the concentration ratio of amino acids and glucose, the effect of increase in the primary glucose
concentration on productivity of γ-interferon was investigated. It was found that 25 g/l glucose will result in maximum attainable
biomass and recombinant human γ-interferon. At improved conditions, a dry cell weight of 14 ± 0.2 g/l, concentration and overall
productivity of γ-interferon 4.2 ± 0.1 g/l and 420 ± 10 mg/l h, respectively, were obtained. 相似文献
12.
Redondo AH Körber C König S Längin A Al-Ahmad A Weinmann W 《Analytical and bioanalytical chemistry》2012,402(7):2417-2424
Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are direct alcohol consumption markers widely used nowadays for clinical and
forensic applications. They are detectable in blood and urine even after consumption of trace amounts of ethanol and for a
longer time frame, being detectable even when no more ethanol is present. The instability of EtG against bacterial degradation
in contaminated urine samples and/or the possible postcollection synthesis of this metabolite in samples containing, e.g.,
Escherichia coli and ethanol, may cause false identification of alcohol uptake. Therefore, it is of paramount importance to constrict these
error sources by inhibition of any bacterial growth causing hydrolization or synthesis of EtG. This study evaluates a new
method of collecting urine samples on filter paper, dried urine spots (DUS), for simultaneous detection of EtG, EtS and creatinine,
having the great advantage of inhibiting bacterial activity. In addition, a method validation for the determination of EtG
and EtS in DUS was performed according to the FDA guidelines. Sterile-filtered urine was spiked with EtG and EtS, inoculated
with E. coli and incubated. Liquid and dried urine samples were collected after various time intervals up to 96 h. Liquid samples were
frozen immediately after collection, whereas aliquots for DUS were pipetted onto filter paper, allowed to dry and stored at
RT until analysis 1 week after. The specimens were analyzed by LC–ESI–MS/MS. As expected, degradation of EtG, but not of EtS,
was observed in contaminated liquid urine samples. However, the specimens collected on filter paper and stored at RT showed
no degradation during storage. Therefore, collecting urine samples on filter paper for EtG and EtS analysis turns out to be
a reliable method to avoid bacterial degradation of EtG and EtS, and consequently, stabilization of these ethanol metabolites
is achieved. In addition, simultaneous measurement of creatinine content as an indicator of urine dilution helps to interpret
the results. Method validation for EtG and EtS in DUS was satisfactory, showing the linearity of the calibration curves in
the studied concentration range, good precision, accuracy and selectivity. 相似文献
13.
Glycerol would stimulate the production of poly(γ-glutamic acid) (γ-PGA) and decrease its molecular weight in Bacillus subtilis NX-2. When 20 g/l glycerol was added in the medium, the yield of γ-PGA increased from 26.7 ± 1.0 to 31.7 ± 1.3 g/l, and molecular
weight of γ-PGA decreased from 2.43 ± 0.07 × 106 to 1.86 ± 0.06 × 106 Da. In addition, it was found that the decrease of γ-PGA chain length by glycerol would lead to the decrease of broth viscosity
during the fermentation and enhanced the uptake of substrates, which could not only improve cell growth but also stimulate
γ-PGA production. Moreover, it was also found that glycerol could effectively regulate molecular weight between 2.43 ± 0.07 × 106 and 1.42 ± 0.05 × 106 Da with the concentration ranging from 0 to 60 g/l. This was the first time to discover such contribution of glycerol on
γ-PGA production in Bacillus genus. And the effects of glycerol on molecular weight of γ-PGA would be developed to be an approach for the regulation of
microbial γ-PGA chain length, which is of practical importance for future commercial development of this polymer. 相似文献
14.
Morini L Politi L Groppi A Stramesi C Polettini A 《Journal of mass spectrometry : JMS》2006,41(1):34-42
A method for the determination of ethyl glucuronide (EtG) in hair samples, using liquid chromatography/electrospray tandem mass spectrometry (LC/ESI-MS/MS), was developed and validated. The treatment of hair samples was as follows: to 100 mg of washed (dichloromethane followed by methanol, 1 ml each) and cut (1-2 mm) material, 700 microl of water, 20 microl of internal standard solution (pentadeuterated EtG, D(5)-EtG, 500 microg/l) and 20 microl of methanol were added. Samples were incubated at 25 degrees C overnight and then ultrasonicated for 2 h. Finally, 8 microl of the centrifuged solution (13,000 rpm) were analyzed by LC/ESI-MS/MS in negative ion mode. The surviving ions of EtG and D(5)-EtG were monitored together with the following MRM transitions: m/z 221 --> 75, m/z 221 --> 85 (EtG) and m/z 226 --> 75, m/z 226 --> 85 (D(5)-EtG). The method exhibited a mean correlation coefficient better than 0.9998 over the dynamic range (3-2000 pg/mg). The lower limit of quantification (LLOQ) and the limit of detection (LOD) were 3 and 2 pg/mg respectively. The intra- and interday precision and accuracy were studied at four different concentration levels (3, 5, 56 and 160 pg/mg) and were always better than 7% (n = 5). Matrix effects did not exceed 20%. The method was applied to several hair samples taken from autopsies of known alcoholics, from patients in withdrawal treatment, from social drinkers, from adult teetotalers and from children not exposed to ethanol, with EtG concentrations globally ranging from < or =2 to 4180 pg/mg. 相似文献
15.
Nakamura S Wada M Crabtree BL Reeves PM Montgomery JH Byrd HJ Harada S Kuroda N Nakashima K 《Analytical and bioanalytical chemistry》2007,387(6):1983-1990
A sensitive semi-micro column HPLC method with peroxyoxalate chemiluminescence (POCL) detection and column switching has been
developed for simultaneous determination of 3,4-methylenedioxymethamphetamine (MDMA) and related compounds, for example 3,4-methylenedioxyamphetamine,
methamphetamine, and amphetamine, in hair. After digestion of the hair with 1 mol L−1 sodium hydroxide the compounds were extracted with n-heptane and derivatized with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole. A mixture of hydrogen peroxide and bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate
in acetonitrile was used as post-column CL reagent. Calibration plots showed linearity was good (r = 0.999); detection limits were 0.02–0.16 ng mg−1 hair at a signal-to-noise ratio of 3. The precision of the method, as RSD (n = 5), in intra-day and inter-day assays was better than 5.0 and 6.9%, respectively. The proposed method was sufficiently
sensitive to detect low ng mg−1 levels of MDMA and related compounds in hair, and could be used for quantification of the compounds in hair samples from
patients treated in a chemical dependency unit. 相似文献
16.
Giovannoli C Anfossi L Baggiani C Giraudi G 《Analytical and bioanalytical chemistry》2008,392(3):385-393
Experimental work performed was aimed at the assessment of a competitive capillary electrophoresis immunoassay with laser-induced
fluorescence (CEIA-LIF) detection for the determination of the Cry1Ab endotoxin from Bacillus thuringensis. The binding constant of a monoclonal antibody, raised against the insecticide protein Cry1Ab, was determined on a microplate
by indirect enzyme-linked immunosorbent assay (ELISA) and compared with that obtained in-capillary under nonequilibrium separation
conditions. The two binding constants appear comparable—(5.0 ± 1.2) × 106 M−1 and (9.06 ± 5.7) × 106 M−1—reflecting good preservation of the antibody binding behavior in the capillary electrophoresis format. These results allow
use of a calibration curve possible between 0.2 and 150 nM of endotoxin protein, with a limit of detection of 0.5 nM (33 μg L−1). Preliminary recovery experiments on maize extracts spiked with known amounts of Cry1Ab endotoxin also showed promising
results in detecting the toxin in complex real matrices. 相似文献
17.
Hair analysis is a powerful tool for retrospective drug analysis. By determining the minor ethanol metabolites ethyl glucuronide
(EtG) and fatty acid ethyl esters (FAEEs) in hair, even a previous consumption of alcohol is detectable. However, previous
studies showed a lack of correlation if both parameters are determined simultaneously. A further study was conducted to confirm
or refute these results. One hundred and sixty hair samples were analyzed for EtG and FAEE in the context of driving ability.
In 109 cases, alcohol abstinence was clearly proven and was excluded in 15 cases. In 36 cases, ambiguous results were found.
Possible reasons for the deviating results are discussed. It is recommended, that in context of driving ability diagnostics
the EtG result is determinant. In critical cases FAEE concentrations can be determined for checking purposes, but a negative
FAEE result cannot refute a determined EtG concentration >7 pg/mg. 相似文献
18.
Cortezzi SS Garcia JS Ferreira CR Braga DP Figueira RC Iaconelli A Souza GH Borges E Eberlin MN 《Analytical and bioanalytical chemistry》2011,401(4):1331-1339
A bottom-up label-free mass spectrometric proteomic strategy was used to analyse the protein profiles of the human embryonic
secretome. Culture media samples used for embryonic culture of patients undergoing intracytoplasmic sperm injection cycles
were selected as a test case for this exploratory proof-of-principle study. The media were stored after embryo transfer and
then pooled into positive (n = 8) and negative (n = 8) implantation groups. The absolute quantitative bottom-up technique employed a multidimensional protein identification
technology based on separation by nano-ultra-high pressure chromatography and identification via tandem nano-electrospray
ionization mass spectrometry with data-independent scanning in a hydrid QqTOF mass spectrometer. By applying quantitative
bottom-up proteomics, unique proteins were found exclusively in both the positive- and negative-implantation groups, which
suggest that competent embryos express and secrete unique biomarker proteins into the surrounding culture medium. The selective
monitoring of these possible secretome biomarkers could make viable procedures using single-embryo transfer. 相似文献
19.
A. Bunkowski B. Bödeker S. Bader M. Westhoff P. Litterst J. I. Baumbach 《International Journal for Ion Mobility Spectrometry》2009,12(2):73-79
Using a 63Ni—Ion Mobility Spectrometer (IMS) coupled with a Multi-Capillary Column (MCC) the signals obtained are considered to identify
characteristic peaks of volatile compounds in exhaled human breath samples of 10 mL volume. The breath of 20 patients with
sarcoidosis and suspicion of sarcoidosis because of mediastinal lymp node enlargement was investigated. It could be shown
that a procedure related to a single peak in the IMS-chromatogram delivers a differentiation into the two groups of patients
with confirmed sarcoidosis and such suffering no sarcoidosis. The potential biomarker is characterised by the following parameters
inverse mobility (1/K0) 0.53 ± 0.01 Vs/cm2—retention time 22 ± 5 s. These results are a first step in breath analysis by MCC/IMS in patients with sarcoidosis. 相似文献
20.
E. V. Starodubtseva O. V. Turova M. G. Vinogradov L. S. Gorshkova V. A. Ferapontov 《Russian Chemical Bulletin》2005,54(10):2374-2378
The rate of hydrogenation of γ-ketoesters MeCOCH2CH2COOR (R = Et, Pri, But) in the presence of the chiral RuII—BINAP catalyst (BINAP is 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) greatly increases upon the addition of 5–10 equivalents
of HCl with respect to ruthenium. In the hydrogenation of ethyl levulinate, the optically active γ-hydroxy ester initially
formed would cyclize by ∼95% to give γ-valerolactone with optical purity of 98–99% ee. When the Ru(COD)(MA)2—BINAP—HCl catalytic system is used (COD is 1,5-cyclooctadiene, MA is 2-methylallyl), complete conversion of the ketoester
(R = Et) in EtOH is attained in 5 h at 60 °C under an H2 pressure of 60–70 atm.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2301–2304, October, 2005. 相似文献