Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sensitive liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed to investigate isosteviol pharmacokinetics in vivo. Isosteviol was extracted from plasma with hexane and 4% formic acid. A Phenomenex Synergi 2mu Fusion reversed phase analytical HPLC column (50 mm x 2.0 mm) equipped with a Synergi 2micro Fusion guard column was employed for chromatographic separations. The gradient mobile phase consisted of acetonitrile (ACN) and 20mM ammonium acetate at pH 6.5, starting at 20% ACN and ramping to 80% at 7 min, followed by 80% ACN for 1 min, then 20% ACN for 5 min. Negative SRM was used to monitor the m/z 317.1/317.1 and 317.3/317.3 transitions for isosteviol and 395.0/395.0 and 397.0/397.0 transitions for internal standard. The retention time of isosteviol was 9.2 min. The assay was linear over the range of 50-2,000 ng/mL. The accuracy of the method was in the range of 97-105%. Intra- and inter-day precisions were in the range of 1.5-4.6%. Isosteviol (4 mg/kg) was dosed intravenously and orally to Sprague-Dawley rats (n=6). Plasma samples were collected and analysed. Intravenous isosteviol has a distribution half-life of 35.7+/-9.0 min with the initial distribution volume of 68.1+/-9.4 mL. The total clearance, terminal half-life and steady-state volume of distribution were 1.25+/-0.12 mL/min, 150.6+/-50.5 min and 272.6+/-95.9 mL, respectively. The oral bioavailability of isosteviol was found to be 60.4+/-15.5%.
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PMID:Oral and i.v. pharmacokinetics of isosteviol in rats as assessed by a new sensitive LC-MS/MS method. 1870 Dec 31

This paper presents the development of a programmed temperature vaporization-gas chromatography-tandem mass spectrometry (PTV-GC-MS-MS) method for the determination of PAHs in complex environmental matrices. This method aims at overcoming the current problems in detecting these compounds in matrices such as biota samples. When these matrices are extracted, great amounts of lipid compounds are co-extracted and can interfere with the analysis of PAHs, complicating their identification and quantification. The developed method significantly improves the detection and quantification limits, since PTV-GC-MS-MS can detect compounds at low-ppb level in complex matrices. The instrumental LODs and LOQs achieved lie between 1.04 and 26.9ngl(-1) and 2.06 and 45.4ngl(-1), respectively, and are lower than those calculated in the GC-MS-SIM mode. The LODs and LOQs of the method range between 1.9 and 3.6ngkg(-1) and between 79 and 99ngkg(-1), respectively. The validation of the method were made with a mussel reference material (SRM 2799). The applicability of the method to real mussel samples was also studied. Samples were extracted by means of microwave energy (with acetone:hexane 1:1, v/v) and the extracts were cleaned in a glass column with 22g of alumina. The usefulness of the MS-MS detection was verified. The obtained results were satisfactory, with good accuracy and precision. The proposed PTV-GC-MS-MS method was successfully applied to real mussel samples affected by the Prestige sinking off the Galician coast.
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PMID:Development of a programmed temperature vaporization-gas chromatography-tandem mass spectrometry method for polycyclic aromatic hydrocarbons analysis in biota samples at ultratrace levels. 1876 Jul 91

An analytical method for the determination of organochlorine pesticides (OCPs) in sediment samples involves ultrasonic extraction, solid-phase extraction (SPE), gas-chromatography (GC)/electron-capture detection (ECD), and GC/mass spectrometry (MS). OCPs were extracted from sediment samples by ultrasonication in mixtures of n-hexane and acetone. Several SPE sorbents [Florisil, silica gel, C18, Oasis HLB, and graphitized carbon black (GCB)] were evaluated as means of preliminary purification. GCB SPE cartridges successfully removed major contaminants such as non-polar hydrocarbons when eluted with an acetone-acetonitrile mixture. After purification, the extract was preferentially screened using GC/ECD and confirmed and quantified using GC/MS. The percentage recovery of samples spiked with 10 or 100ng/g OCP ranged from 73.9% to 106.0% with a relative standard deviation of 0.4-5.7%. Detection limits ranged from 0.002 to 0.005ng/g for GC/ECD and from 0.03 to 0.50ng/g for GC/MS detection. The linear dynamic range extended from 0.2 to 20ng/g, with a correlation coefficient (R(2)) greater than 0.995. The method was validated using a standard reference material (SRM 1941b) and spiked sediment samples. Real sediment samples collected from a river near a Korean industrial area exhibited low levels of several OCPs when analyzed using this method.
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PMID:Determination of organochlorine pesticides in sediment using graphitized carbon black solid-phase extraction and gas chromatography/mass spectrometry. 1878 49

A new approach has been developed and tested for the urgent analysis of dioxins in samples of air-dust filters originating from catastrophe emissions. The procedure consists of a fast extraction of the sample with microwave solvent extraction (MASE) and acetone as solvent followed by a fast cleanup of the extract with normal phase coupled column liquid chromatography (LC/LC). The multi-dimensional LC/LC system employs a 50 mm x4.6 mm i.d. column packed with 3mum silica and a 150 mm x4.6 mm i.d. column packed with 5mum PYE as the first and second analytical column, respectively. Iso-hexane is used on both columns to perform cleanup and dichloromethane to perform efficient back-flush elution of the compounds from the second column. The obtained polarity-based separation in the first dimension and molecular-structure based separation in the second dimension provides a fast and powerful cleanup. Validation was done by analysing samples of homemade RIVM air-dust with aged residues (n=8, spiking level about 15pgmg(-1) per compound) of dioxins/furans and samples of reference Urban Dust SRM 1649a (n=4) with both the new approach and the existing conventional procedure and were instrumentally analyzed with capillary gas chromatography and high resolution mass spectrometric detection (GC/HRMS). In comparison to the existing conventional procedure, the new approach reduces sample processing from several days to several hours per sample. As regards the aged-residue air-dust samples, the new method shows a good accuracy, precision and high selectivity providing a performance in good agreement with the existing procedure. In SRM air-dust, the concentration of a few compounds obtained by the new method was below (10-50%) the certified value.
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PMID:Fast sample preparation involving MASE and coupled column normal phase liquid chromatography for the rapid trace analysis of dioxins in air-dust samples from fire catastrophe emissions. 1896 47

A low temperature microwave-assisted extraction method (MAE) is reported for the analysis of polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter (PM). The main parameters affecting the extraction efficiency (choice of extractants, microwave power, and extraction time) were investigated and optimized. The optimized procedure requires a 20 ml mixture of acetone:n-hexane (1:1) for extraction of PAHs in PM at 150W of microwave energy (20 min extraction time). Clean-up of MAE extracts was not found to be necessary. The optimized method was validated using two different SRM (1648-urban particulate matter and 1649a, urban dust). The results obtained are in good agreement with certified values. PAHs recoveries for both reference materials were between 79 and 122% with relative standard deviation ranging from 3 to 21%. Detection limits were determined based on blank determination using two kinds of quartz filter substrates (n=10), which ranged from 0.001 (0.03) ng m(-3)(pg/microg) for B(k)Ft to 1.119 (37.3) for Naph in ng m(-3) (pg/microg), respectively. The repeatability and day-to-day reproducibility obtained in this study were in the range of 4-16 and 3-25% for spiked standards and SRM 1649, respectively. The optimized and validated MAE technique was applied to the extraction of PAHs from a set of real world PM samples collected in Singapore. The sum of particulate-bound PAHs in outdoor PM ranged from 1.05 to 3.45 ng m(-3) while that in indoor PM (cooking emissions) ranged from 27.6 to 75.7 ng m(-3), respectively.
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PMID:Optimization and validation of a low temperature microwave-assisted extraction method for analysis of polycyclic aromatic hydrocarbons in airborne particulate matter. 1897 May 35

A sensitive and automated method is presented for the determination of polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter. The procedure includes extraction of PM10-bound PAHs by accelerated solvent extraction (ASE) followed by gel permeation chromatography (GPC) clean-up, and large-volume programmable temperature vaporizer (PTV-LV) injection coupled to GC-MS. The limit of detection (LOD) of the whole method, based on a signal-to-noise ratio (S/N) of 3:1, ranged from 0.26pgm(-3) to 3pgm(-3) when air volumes of 760m(3) are collected. The hexane-acetone mixture (1:1, v/v) gave the best recoveries when ASE parameters were fixed at 125 degrees C, 1500psi, and a total time of 10min. The recoveries for all PAHs tested ranged from 96% to 103%, rates similar to those obtained by the Soxhlet reference method. To improve the sensitivity, 70muL were injected. The PTV-LV injection settings were optimized using a statistical design of experiments, including a screening 2(4) full factorial design and a further central composite design. A sensitivity increase from 10 to 50 times was achieved as compared with the conventional 2muL splitless injection. The method was validated with the standard reference material SRM 1649a and applied to real PM10 samples from the monitoring network of the Regional Valencia Government (Spain). The analytical performance of the method shows that it is appropriate to monitor PAHs levels in ambient air according to European Union Directives. In addition, the method can be used when a high sensitivity is required.
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PMID:Determination of PAHs in airborne particles by accelerated solvent extraction and large-volume injection-gas chromatography-mass spectrometry. 1897 Jun 41

Validation of a high-throughput measurement system with microwave-assisted extraction (MAE), fully automated sample preparation device (SPD), and gas chromatography-electron capture detector (GC-ECD) for the determination of polychlorinated biphenyls (PCBs) in minke whale blubber was performed. PCB congeners accounting for > 95% of the total PCBs burden in blubber were efficiently extracted with a small volume (20 mL) of n-hexane using MAE due to simultaneous saponification and extraction. Further, the crude extract obtained by MAE was rapidly purified and automatically substituted to a small volume (1 mL) of toluene using SPD without using concentrators. Furthermore, the concentration of PCBs in the purified and concentrated solution was accurately determined by GC-ECD. Moreover, the result of accuracy test using a certified material (SRM 1588b; Cod liver oil) showed good agreement with the NIST certified concentration values. In addition, the method quantification limit of total-PCB in whale blubbers was 41 ng g(-1). This new measurement system for PCBs takes only four hours. Consequently, it indicated this method is the most suitable for the monitoring and screening of PCBs in the conservation of the marine ecosystem and safe distribution of foods.
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PMID:Validation of high-throughput measurement system with microwave-assisted extraction, fully automated sample preparation device, and gas chromatography-electron capture detector for determination of polychlorinated biphenyls in whale blubber. 1909 81

Accelerated solvent extraction (ASE) has been applied to the quantitative extraction of organochlorine compounds (OCs), including organochlorine pesticides (HCHs, DDXs) and polychlorinated biphenyls (PCBs) present in both atmospheric particulate and gaseous phase. Extraction parameters such as the combination of solvents, extraction temperature, and static extraction time were investigated and optimized. Effective extraction can be carried out using a 3:1 mixture of n-hexane and acetone as extraction solvents at 100 degrees C in 20min for all the compounds studied. The entire analytical procedure developed in this study proves to be reliable as evident from the analysis of specific surrogate standards with the mean recoveries per sample being greater than 82%. The optimized method was validated using NIST-certified SRM 1649a. Semi-volatile OCs, in the atmosphere of Singapore were quantified using the optimized ASE method together with GC-MS. Total average concentrations of SigmaHCHs, SigmaDDXs, and SigmaPCBs in air samples were 244.9+/-88.5pgm(-3), 7.7+/-4.1pgm(-3), and 34.1+/-19.7pgm(-3), respectively. The distribution of these compounds between the gas and particulate phase is discussed. Possible sources of atmospheric OCs are evaluated based on the molecular ratio of specific compounds and backward air trajectory analysis.
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PMID:Determination of semi-volatile organochlorine compounds in the atmosphere of Singapore using accelerated solvent extraction. 1920 May 69

A simple, inexpensive sample preparation procedure, based on the matrix solid-phase dispersion (MSPD) technique, for the determination of six UV filters: 2-ethylhexyl salicylate (EHS), 3,3,5-trimethylcyclohexyl salicylate (Homosalate, HMS), 3-(4-methylbenzylidene) camphor (4-MBC), isoamyl-p-methoxycinnamate (IAMC), 2-ethylhexyl-p-methoxycinnamate (EHMC) and octocrylene (OCR), in dust from indoor environments is presented and the influence of several operational parameters on the extraction performance discussed. Under the final working conditions, sieved samples (0.5 g) were mixed with the same amount of anhydrous sodium sulphate and dispersed with 2 g of octadecyl bonded silica (C18) in a mortar with a pestle. This blend was transferred to a polypropylene solid-phase extraction cartridge containing 2 g of activated silica, as the clean-up co-sorbent. The cartridge was first rinsed with 5 mL of n-hexane and the analytes were then recovered with 4 mL of acetonitrile. This extract was adjusted to 1 mL, filtered and the compounds were determined by gas chromatography combined with tandem mass spectrometry (GC-MS/MS). Recoveries for samples spiked at two different concentrations ranged between 77% and 99%, and the limits of quantification (LOQs) of the method between 10 and 40 ng g(-1). Analysis of settled dust from different indoor areas, including private flats, public buildings and vehicle cabins, showed that EHMC and OCR were ubiquitous in this matrix, with maximum concentrations of 15 and 41 microg g(-1), respectively. Both UV filters were also quantified in dust reference material SRM 2585 for first time. EHS, 4-MBC and IAMC were detected in some of the analyzed samples, although at lower concentrations than EHMC and OCR.
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PMID:Determination of selected UV filters in indoor dust by matrix solid-phase dispersion and gas chromatography-tandem mass spectrometry. 1953 93

A fast and simple method for the analysis of polybrominated diphenyl ethers (PBDEs) in fish samples was developed using a one-step extraction and clean-up by means of pressurized liquid extraction (PLE) combined with gas chromatography-ion trap tandem mass spectrometry (GC-ITMS-MS). The selective PLE method provided to obtain ready-to-analyse extracts without any additional clean-up step, using a sorbent as fat retainer inside the PLE cell. Several PLE operating conditions, such as solvent type, extraction temperature and time, number of cycles and type of fat retainer, were studied. Using Florisil as fat retainer, maximum recoveries of PBDEs (83-108%) with minimum presence of matrix-interfering compounds were obtained using a mixture of n-hexane:dichloromethane 90:10 (v/v) as solvent, an extraction temperature of 100 degrees C and a static extraction time of 5 min in combination with three static cycles. Quality parameters of the method were established using standards and fish samples. Limits of detection and quantification ranged from 10 to 34 pg g(-1) wet weight and between 34 and 68 pg g(-1) wet weight, respectively. In addition, good linearity (between 1 and 500 ng ml(-1)) and high precision (RSD %<15%) were achieved. The method was validated using the standard reference material SRM-1945 (whale blubber) and was then applied to the analysis of PBDEs in fish samples.
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PMID:Selective pressurized liquid extraction of polybrominated diphenyl ethers in fish. 1983 61


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