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https://www.readbyqxmd.com/read/28109254/letm-presented-with-causalgia-and-ensued-by-sudden-death
#1
Rana Alnasser Alsukhni, Yasmin Aboras, Ziena Jriekh, Mahmoud Almalla, Ahmad Sheikh El-Kahwateya
BACKGROUND: Longitudinally Extensive Transverse Myelitis LETM is a specific pattern of myelitis wherein at least three continuous vertebral segments are involved. Characteristically, it is a defining feature of neuromyelitis optica NMO. However, it is described in many other etiologies. CASE PRESENTATION: We present a case of 60 year old male who presented with symptoms and signs of regional sympathetic dystrophy RSD followed by symptoms of myelitis. Spinal cord MRI revealed cervical LETM extending to the brainstem...
January 21, 2017: BMC Neurology
https://www.readbyqxmd.com/read/28107995/multivariate-optimization-of-headspace-trap-for-furan-and-furfural-simultaneous-determination-in-sponge-cake
#2
Mayela Cepeda-Vázquez, David Blumenthal, Valérie Camel, Barbara Rega
Furan, a possibly carcinogenic compound to humans, and furfural, a naturally occurring volatile contributing to aroma, can be both found in thermally treated foods. These process-induced compounds, formed by close reaction pathways, play an important role as markers of food safety and quality. A method capable of simultaneously quantifying both molecules is thus highly relevant for developing mitigation strategies and preserving the sensory properties of food at the same time. We have developed a unique reliable and sensitive headspace trap (HS trap) extraction method coupled to GC-MS for the simultaneous quantification of furan and furfural in a solid processed food (sponge cake)...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107989/adsorption-and-deposition-assisted-anodic-stripping-voltammetry-for-determination-of-antimony-iii-in-presence-of-hematoxylin-on-glassy-carbon-electrode
#3
Hanife Vardar Sezgin, Yusuf Dilgin, H İsmet Gökçel
A validated simple, reliable and sensitive adsorptive anodic stripping voltammetric procedure is suggested for the accurate determination of antimony(III) on a glassy carbon electrode (GCE) in the presence of hematoxylin (HT), used as a chemical receptor in antimony analysis for the first time. Under optimized conditions, the plot of stripping peak current versus Sb(III) concentration showed two dynamic linear ranges, 1.0×10(-4) - 0.01µm (R(2) =0.9986) and 0.01 - 1.0µm (R(2) =0.9973) with a detection limit of 9...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107974/analysis-of-bromophenols-in-various-aqueous-samples-using-solid-phase-extraction-followed-by-hplc-ms-ms
#4
Xiyuan Chi, Jiyan Liu, Miao Yu, Zhouqing Xie, Guibin Jiang
A reliable and effective method for simultaneous analysis of trace amount of bromophenols (BPs) in various aqueous samples was developed in this study. The aqueous samples must be acidified after sampling to prevent the fast degradation of bromophenols. Solid-phase extraction was chosen to extract and purify the water samples. High performance liquid chromatography coupled with tandem mass spectrometry with an electrospray ionization source (HPLC-ESI-MS/MS) was used for following identification and quantification...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107942/stereoselective-quantification-of-triticonazole-in-vegetables-by-supercritical-fluid-chromatography
#5
Qi Tan, Jun Fan, Ruiqi Gao, Rujian He, Tai Wang, Yaomou Zhang, Weiguang Zhang
A highly fast analytical method though supercritical fluid chromatography (SFC) has been developed to quantify triticonazole enantiomers in cucumbers and tomatoes. Effects of organic modifier type and concentration on chiral separation and quantification of standard solution as well as matrix-matched standard solutions have been studied in detail. Among three organic modifiers, better separation of triticonazole racemate was achieved with 20% ethanol (v/v). The run time in SFC (ca 3min) with CO2-ethanol (80:20, v/v) as the mobile phase was six-fold shorter than HPLC analysis (about 18min)...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28107920/evaluation-of-liquid-cathode-glow-discharge-atomic-emission-spectrometry-for-determination-of-copper-and-lead-in-ores-samples
#6
Jie Yu, Shuxiu Yang, Quanfang Lu, Duixiong Sun, Jidong Zheng, Xiaomin Zhang, Xing Wang, Wu Yang
In this study, a liquid cathode glow discharge-atomic emission spectrometry (LCGD-AES) was constructed for simultaneously determination of Cu and Pb in digested ores samples, in which the glow discharge was produced between the needle-like Pt anode and electrolyte overflowing from quartz capillary. The stability of LCGD and the effects of discharge voltage, capillary diameter and flow rate on emission intensity were systematically investigated. The limits of detections (LODs) of Cu and Pb were compared with those measured by closed-type electrolyte cathode discharge-atomic emission spectrometry (ELCAD-AES)...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28106344/fast-separation-of-flavonoids-by-supercritical-fluid-chromatography-using-a-column-packed-with-a-sub-2%C3%A2-%C3%AE-m-particle-stationary-phase
#7
Bo Wang, Xiao-Hua Liu, Wei Zhou, Yan Hong, Shi-Lan Feng
The purpose of this study was to compare the effects of different chromatographic columns for the separation of seven flavonoids. Four different stationary phases are available, including BEH, BEH 2-EP, CSH fluorophenyl and HSS C18 SB. The analytes included calycosin, genistein, medicarpin, calycosin-7-O-β-d-glucoside, formononetin, formononetin-7-O-β-d-glucoside and liquiritigenin. The CSH fluorophenyl column was determined to be the most suitable and provided the fastest separation within 17 min using gradient elution with carbon dioxide as the mobile phase and methanol as the co-solvent...
January 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28105971/determination-of-tryptamines-and-%C3%AE-carbolines-in-ayahuasca-beverage-consumed-during-brazilian-religious-ceremonies
#8
Mônica Cardoso Santos, Sandro Navickiene, Alain Gaujac
Ayahuasca is a potent hallucinogenicbeverage prepared from <em>Banisteriopsis caapi</em>in combination with other psychoactive plants.<em>N</em>,<em>N</em>-dimethyltryptamine, tryptamine, harmine,harmaline, harmalol, and tetrahydroharmine werequantified in ayahuasca samples using a simpleand low-cost method based on SPE and LC with UVdiode-array detection. The experimental variablesthat affect the SPE method, such as type of solidphase and nature of solvent, were optimized...
January 19, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28105847/compact-ultrahigh-pressure-nanoflow-capillary-liquid-chromatograph
#9
Xiaofeng Zhao, Xiaofeng Xie, Sonika Sharma, Luke T Tolley, Alex Plistil, Hal E Barnett, Martin P Brisbin, Adam C Swensen, John C Price, Paul B Farnsworth, H Dennis Tolley, Stanley D Stearns, Milton L Lee
A compact ultrahigh-pressure nanoflow liquid chromatograph (LC) was developed with the purpose in mind of creating a portable system that could be easily moved to various testing locations or placed in close proximity to other instruments for optimal coupling, such as with mass spectrometry (MS). The system utilized innovative nanoflow pumps integrated with a very low volume stop-flow injector and mixing tee. The system weighed only 5.9 kg (13 lbs) or 4.5 kg (10 lbs) without a controller and could hold up to 1100 bar (16000 psi) of pressure...
January 3, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28094519/targeted-multiresidue-analysis-of-veterinary-drugs-in-milk-based-powders-using-liquid-chromatography-tandem-mass-spectrometry-lc-ms-ms
#10
James B Wittenberg, Kelli A Simon, Jon W Wong
An analytical method was developed and validated for the determination of 40 veterinary drugs in various milk-based powders. The method involves acetonitrile/water extraction, solid-phase filtration for lipid removal in fat-containing matrices, and analysis using liquid chromatography tandem mass spectrometry (LC-MS/MS). The limits of quantitation (LOQ) ranged from 0.02 to 82 ng/g. Acceptable recoveries (70-120%, RSD < 20%) were reached for 40 out of 52 target compounds at three fortification levels in non-fat milk powder...
January 17, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28094507/conjugated-polyelectrolyte-based-sensitive-detection-and-removal-of-antibiotics-tetracycline-from-water
#11
Akhtar Hussain Malik, Parameswar Krishnan Iyer
A new conjugated polyelectrolyte poly[5,5'-(((2-phenyl-9H-fluorene-9,9-diyl)bis(hexane-6,1-diyl))bis(oxy))diisophthalate] sodium (PFPT) was synthesized via Palladium catalysed Suzuki cross coupling polymerization method and successfully applied for the rapid, real time and highly sensitive detection of antibiotics tetracycline (Tc) in 100% aqueous media via photo-induced electron transfer with detection limit in ppb level. Remarkably, PFPT could also be applied for the trace analysis of Tc in serum samples having recoveries well in the range 92-97% with relative standard deviations (RSD) of 1...
January 17, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28093672/influence-of-quechers-modifications-on-recovery-and-matrix-effect-during-the-multi-residue-pesticide-analysis-in-soil-by-gc-ms-ms-and-gc-ecd-npd
#12
Bożena Łozowicka, Ewa Rutkowska, Magdalena Jankowska
A QuEChERS extraction followed by GC/MS/MS and GC-μECD/NPD for 216 pesticide and metabolites determination in soil simultaneously were developed and compared. Volume of water, volume and polarity of solvent, and cleanup sorbents (C18, GCB, PSA) were optimized. The QuEChERS with and without purification step were applied to estimate effectiveness of the method. The recovery and matrix effect (ME) were critical parameters within each tested procedure. The optimal method without cleanup was validated. Accuracy (expressed as recovery), precision (expressed as RSD), linearity, LOQ, and uncertainty were determined...
January 16, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28093127/magnetic-beads-based-dna-hybridization-chain-reaction-amplification-and-dnazyme-recognition-for-colorimetric-detection-of-uranyl-ion-in-seafood
#13
Hongyan Zhang, Xian Cheng, Lian Chen, Fan Mo, LiangJun Xu, FengFu Fu
A novel colorimetric biosensor, which employs DNAzyme-functionalized magnetic beads (MBs) as recognition probe, enzyme-assisted catalytic oxidation of TMB (3,3',5,5'-tetramethylbenzidine sulfate) as signal and DNA hybridization chain reaction as amplification strategy, has been developed for detecting trace uranyl ion (UO2(2+)) in seafood and aqueous environment with high sensitivity and specificity. We demonstrated that UO2(2+) can specifically cleave DNAzyme immobilized on MBs surface to release a short single-strand DNA (primer), and the released primer trigger DNA hybridization chain reaction to form a long one dimensional DNA concatamer on the MBs surface...
March 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28093121/phenyltrichlorosilane-functionalized-magnesium-oxide-microspheres-preparation-characterization-and-application-for-the-selective-extraction-of-dioxin-like-polycyclic-aromatic-hydrocarbons-in-soils-with-matrix-solid-phase-dispersion
#14
Dongqin Tan, Jing Jin, Fang Li, Xiaoli Sun, Dhanjai, Yuwen Ni, Jiping Chen
Magnesium oxide microspheres functionalized with phenyltrichlorosilane (PTS-MgO) were synthesized by surface modification through silanization reaction, which was confirmed by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry analysis (TGA) and N2 adsorption-desorption. The result indicated that PTS-MgO not only possessed the ability of enhancing the retention with PAHs, but also weakening the interference from chlorinated compounds. As a sorbent for the matrix solid-phase dispersion (MSPD) extraction, PTS-MgO was used to selectively extract seven dioxin-like polycyclic aromatic hydrocarbons (DL-PAHs) from soil samples...
March 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28092827/conjugated-polymer-with-carboxylate-groups-hg-2-system-as-a-turn-on-fluorescence-probe-for-label-free-detection-of-cysteine-containing-compounds
#15
Hongyu Mi, Mingming Guan, Jilin Liu, Hongyan Shan, Qiang Fei, Yanfu Huan, Guodong Feng
In this work, a turn on fluorescent sensor, based on Hg(2+) coordination conjugated polymer, was developed to detect cysteine-containing compounds. The fluorescence of conjugated polymer (poly(2,5-bis (sodium 4-oxybutyrate) -1,4 - phenylethynylene-alt-1,4-phenyleneethynylene; PPE-OBS) would be quenched by Hg(2+) because of the coordination-induced aggregation and electron transfers of PPE-OBS toward Hg(2+). When there were some cysteine-containing compounds in PPE-OBS-Hg(2+) system, the fluorescence of PPE-OBS would be recovered...
January 13, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28092076/determination-of-trace-elements-in-cow-placenta-by-tungsten-coil-atomic-emission-spectrometry
#16
Daniel A Gonçalves, Ana C Soncin, George L Donati, Mirian C Dos Santos
Tungsten coil atomic emission spectrometry (WCAES) is used to determine trace levels of Mn (403.1 nm) and Cr (425.5 nm) in cow placenta. All samples were collected in Ilha Solteira, SP, Brazil. The instrumental setup is based on a tungsten filament extracted from 150 W, 15 V microscope light bulbs, a solid state power supply, fused silica lens, crossed Czerny-Turner spectrograph, and a thermoelectrically cooled charge-coupled device detector. The limits of detection (LOD) and quantification (LOQ) for Cr are 2 and 8 μg L(-1), and 20 and 60 μg L(-1) for Mn, respectively...
January 16, 2017: Biological Trace Element Research
https://www.readbyqxmd.com/read/28091717/bar-adsorptive-microextraction-technique-application-for-the-determination-of-pharmaceuticals-in-real-matrices
#17
Carlos Almeida, Samir M Ahmad, José Manuel F Nogueira
In the present work, bar adsorptive microextraction using miniaturized devices (7.5 × 3.0 mm) coated with suitable sorbent phases, combined with microliquid desorption (100 μL) followed by high-performance liquid chromatography with diode array detection (BAμE-μLD/HPLC-DAD), is proposed for the determination of trace level of six pharmaceuticals (furosemide, mebeverine, ketoprofen, naproxen, diclofenac and mefenamic acid) in environmental water and urine matrices. By comparing ten distinct sorbent materials (five polymeric and five activated carbons), the polymer P5 proved to be the most suitable to achieve the best selectivity and efficiency...
January 16, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28089277/accurate-determination-of-residual-acrylic-acid-in-superabsorbent-polymer-of-hygiene-products-by-headspace-gas-chromatography
#18
Shu-Xin Zhang, Xin-Sheng Chai, Ran Jiang
This work reports on a method for the determination of residual acrylic acid (AA) in the superabsorbent polymers for hygiene products by headspace analysis. It was based on water extraction for the polymer sample at a room temperature for 50min. Then, the AA in the extractant reacted with bicarbonate solution in a closed headspace sample vial, from which the carbon dioxide generated from the reaction (within 20min at 70°C) was detected by gas chromatography (GC). It was found that there is adsorption partition equilibrium of AA between solid-liquid phases...
January 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28088360/hollow-porous-ionic-liquids-composite-polymers-based-solid-phase-extraction-coupled-online-with-high-performance-liquid-chromatography-for-selective-analysis-of-hydrophilic-hydroxybenzoic-acids-from-complex-samples
#19
Xingping Dai, Dongsheng Wang, Hui Li, Yanyi Chen, Zhicheng Gong, Haiyan Xiang, Shuyun Shi, Xiaoqing Chen
Polar and hydrophilic properties of hydroxybenzoic acids usually made them coelute with interferences in high performance liquid chromatography (HPLC) analysis. Then selective analysis of them was necessary. Herein, hollow porous ionic liquids composite polymers (PILs) based solid phase extraction (SPE) was firstly fabricated and coupled online with HPLC for selective analysis of hydroxybenzoic acids from complex matrices. Hollow porous PILs were firstly synthesized using Mobil Composition of Matter No. 48 (MCM-48) spheres as sacrificial support, 1-vinyl-3-methylimidazolium chloride (VMIM(+)Cl(-)) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker...
January 9, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28081498/enhancing-analysis-throughput-sensitivity-and-specificity-in-lc-esi-ms-ms-assay-of-plasma-25-hydroxyvitamin-d3-by-derivatization-with-triplex-4-4-dimethylaminophenyl-1-2-4-triazoline-3-5-dione-daptad-isotopologues
#20
Shoujiro Ogawa, Hiroki Kittaka, Akiho Nakata, Kenji Komatsu, Takahiro Sugiura, Mamoru Satoh, Fumio Nomura, Tatsuya Higashi
The plasma/serum concentration of 25-hydroxyvitamin D3 [25(OH)D3] is a diagnostic index for vitamin D deficiency/insufficiency, which is associated with a wide range of diseases, such as rickets, cancer and diabetes. We have reported that the derivatization with 4-(4-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione (DAPTAD) works well in the liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) assay of the serum/plasma 25(OH)D3 for enhancing the sensitivity and the separation from a potent interfering metabolite, 3-epi-25-hydroxyvitamin D3 [3-epi-25(OH)D3]...
November 17, 2016: Journal of Pharmaceutical and Biomedical Analysis
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