keyword
MENU ▼
Read by QxMD icon Read
search

ion chromatography

keyword
https://www.readbyqxmd.com/read/28343344/simultaneous-detection-of-chlorinated-polycyclic-aromatic-hydrocarbons-with-polycyclic-aromatic-hydrocarbons-by-gas-chromatography-mass-spectrometry
#1
Meng Qiao, Wei Cao, Bochuan Liu, Xu Zhao, Jiuhui Qu
Chlorinated polycyclic aromatic hydrocarbons (ClPAHs), including polychlorinated naphthalenes (PCNs), are hazardous and widespread in the environment, but studies of these substances in the wastewater environment are lacking. In this study, five typical PCNs and five typical ClPAHs (other than PCNs) were simultaneously detected along with their parent polycyclic aromatic hydrocarbons in wastewater samples. All these compounds could be analyzed by gas chromatography- electron ionization mass spectrometry in selected ion monitoring mode and separated on a DB-17ms column...
March 25, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28343077/separation-and-characterization-of-unknown-impurities-and-isomers-in-flomoxef-sodium-by-lc-it-tof-ms-and-study-of-their-negative-ion-fragmentation-regularities
#2
Xu Yu, Fan Wang, Jiani Li, Weiguang Shan, Bingqi Zhu, Jian Wang
Thirteen unknown impurities in flomoxef sodium were separated and characterized by liquid chromatography coupled with high resolution ion trap/time-of-flight mass spectrometry (LC-IT-TOF MS)with positive and negative modes of electrospray ionization method for further improvement of official monographs in pharmacopoeias. The fragmentation patterns of impurities in flomoxef in the negative ion mode were studied in detail, and new negative-ion fragmentation regularities were discovered. Chromatographic separation was performed on a Kromasil C18 column (250mm×4...
March 19, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28343038/physicochemical-characterization-of-ambient-pm2-5-in-tehran-air-and-its-potential-cytotoxicity-in-human-lung-epithelial-cells-a549
#3
Anoushiravan MohseniBandpi, Akbar Eslami, Abbas Shahsavani, Fariba Khodagholi, Abdolazim Alinejad
As air pollution is a major problem in Tehran, this study aimed to investigate the physicochemical characterization of the water-soluble and organic contents of ambient PM2.5 in Tehran and determine its in vitro toxicological impact on human lung epithelial cells (A549). A total of 11 sampling stations were selected, including three categories: traffic, urban, and suburban. All sampling was carried out in the spring and summer of 2015. Ion chromatography (IC), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and GC-MS were used to analyze ionic compounds, heavy metals, and polycyclic aromatic hydrocarbons (PAHs), respectively, and an ELISA reader was used for cytotoxicity analysis...
March 23, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28342304/rapid-profiling-and-pharmacokinetic-studies-of-major-compounds-in-crude-extract-from-polygonum-multiflorum-by-uhplc-q-tof-ms-and-uplc-ms-ms
#4
Linlin Wang, Mangmang Sang, Erwei Liu, Prince Osei Banahene, Yi Zhang, Tao Wang, Lifeng Han, Xiumei Gao
A reliable, rapid analytical method was established for characterization of constituents in the ethanol extract of Polygonum multiflorum by combining an ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). 131 constituents which including phenolic acids, stilbenes, flavones, anthraquinones, naphthalenes and their derivatives were identified or tentatively identified by using characteristic diagnostic fragment ions and references. The established method was further applied to analyze blood samples, and successfully identified 41 compounds which were absorbed through the gastrointestine in rats after administration the extract of P...
March 18, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28340481/metabolic-profiling-of-tyrosine-tryptophan-and-glutamate-in-human-urine-using-gas-chromatography-tandem-mass-spectrometry-combined-with-single-spe-cleanup
#5
Hyun Ju Shin, Na Hyun Park, Wonwoong Lee, Man Ho Choi, Bong Chul Chung, Jongki Hong
The tyrosine, tryptophan, and glutamate metabolic pathways play key roles on pathological state of neuronal functions and the change of their levels in biological systems reflects the progress degree of neuronal diseases. Comprehensive profiling of these metabolites is important to find new biomarkers for diagnosis or prognosis of various neuronal diseases. However, the overall profiling analysis of various neurochemicals in biological sample is confronted with several limitations due to their low concentration and physicochemical properties and the coexistence of matrices...
March 16, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28340480/using-uhplc-q-trap-ms-as-a-complementary-technique-to-in-depth-mine-uplc-q-tof-ms-data-for-identifying-modified-nucleosides-in-urine
#6
Zhiwei Lu, Qing Wang, Meiling Wang, Shuang Fu, Qingqing Zhang, Zhixin Zhang, Huizhen Zhao, Yuehong Liu, Zhenhai Huang, Ziye Xie, Honghong Yu, Xiaoyan Gao
Modified nucleosides, metabolites of RNA, are potential biomarkers of cancer before the appearance of morphological abnormalities. It is of great significance to comprehensively detect and identify nucleosides in human urine for discovery of cancer biomarkers. However, the lower abundance, the greater polarity and the matrix effects make it difficult to detect urinary nucleosides. In this paper, an integrated method consisted of sample preparation followed by ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC Q-TOF/MS) detection and primary identification, then ultra-high performance liquid chromatography coupled with hybrid triple quadrupole linear ion trap mass spectrometer (UHPLC Q-Trap/MS) further identification and validation were introduced...
March 12, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28340471/chemotaxonomic-studies-of-nine-paris-species-from-china-based-on-ultra-high-performance-liquid-chromatography-tandem-mass-spectrometry-and-fourier-transform-infrared-spectroscopy
#7
Yuanzhong Wang, Ehu Liu, Ping Li
Paris species, which contain steroid saponins, have been used as herb folk medicines in Asia. In the present study, a comprehensive strategy based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and Fourier transform infrared (FT-IR) spectroscopy was firstly proposed to evaluate the chemotaxonomic relationships of nine Paris species sampled from different geographical regions in China. Principle component analysis (PCA) based on FT-IR data revealed chemical similarities in term of the nine species and geographical regions, indicating the accumulation of metabolites affected by the combination of geographical factors and species...
March 18, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28335386/revisiting-the-metabolism-and-bioactivation-of-ketoconazole-in-human-and-mouse-using-liquid-chromatography-mass-spectrometry-based-metabolomics
#8
Ju-Hyun Kim, Won-Gu Choi, Sangkyu Lee, Hye Suk Lee
Although ketoconazole (KCZ) has been used worldwide for 30 years, its metabolic characteristics are poorly described. Moreover, the hepatotoxicity of KCZ limits its therapeutic use. In this study, we used liquid chromatography-mass spectrometry-based metabolomics to evaluate the metabolic profile of KCZ in mouse and human and identify the mechanisms underlying its hepatotoxicity. A total of 28 metabolites of KCZ, 11 of which were novel, were identified in this study. Newly identified metabolites were classified into three categories according to the metabolic positions of a piperazine ring, imidazole ring, and N-acetyl moiety...
March 13, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28333338/drug-discovery-for-male-subfertility-using-high-throughput-screening-a-new-approach-to-an-unsolved-problem
#9
Sarah J Martins da Silva, Sean G Brown, Keith Sutton, Louise V King, Halil Ruso, David W Gray, Paul G Wyatt, Mark C Kelly, Christopher L R Barratt, Anthony G Hope
STUDY QUESTION: Can pharma drug discovery approaches be utilized to transform investigation into novel therapeutics for male infertility? SUMMARY ANSWER: High-throughput screening (HTS) is a viable approach to much-needed drug discovery for male factor infertility. WHAT IS KNOWN ALREADY: There is both huge demand and a genuine clinical need for new treatment options for infertile men. However, the time, effort and resources required for drug discovery are currently exorbitant, due to the unique challenges of the cellular, physical and functional properties of human spermatozoa and a lack of appropriate assay platform...
March 16, 2017: Human Reproduction
https://www.readbyqxmd.com/read/28332747/ultra-performance-liquid-chromatography-hyphenated-with-quadrupole-orbitrap-mass-spectrometry-for-simultaneous-determination-of-necine-core-structure-pyrrolizidine-alkaloids-in-crotalaria-sessiliflora-l-without-all-corresponding-standards
#10
Wei Zhang, Wenbei Huai, Yi Zhang, Jincan Shen, Xunyou Tang, Xiujuan Xie, Ke Wang, Huajun Fan
INTRODUCTION: Crotalaria sessiliflora L. is a Chinese traditional herb for treatment of cutaneum carcinoma and cervical carcinoma. In addition to monocrotaline, coexisting pyrrolizidine alkaloids (PAs) also require further quantification for quality control and pharmaceutical uses of the herb. OBJECTIVE: To establish a UPLC-Q-Orbitrap/MS method of simultaneous determination of coexisting PAs with same parent structure for quality control and comprehensive researches of Crotalaria sessiliflora L...
March 23, 2017: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28330273/purification-and-characterization-of-polygalacturonase-from-aspergillus-fumigatus-mtcc-2584-and-elucidating-its-application-in-retting-of-crotalaria-juncea-fiber
#11
Gautam Anand, Sangeeta Yadav, Dinesh Yadav
Polygalacturonases represents an important member of pectinases group of enzymes with diverse industrial applications and is widely distributed among fungi, bacteria, yeasts, plants and some plant parasitic nematodes. An endo-polygalacturonase from a new fungal source Aspergillus fumigatus MTCC 2584 was produced under solid-state fermentation conditions and was purified simply by acetone precipitation and gel-filtration chromatography technique. The approximate molecular weight of the purified PG was found to be 43...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330233/improvement-of-shelf-life-of-soymilk-using-immobilized-protease-of-oerskovia-xanthineolytica-ncim-2839
#12
A K Sahoo, V S Gaikwad, R C Ranveer, P B Dandge, S R Waghmare
Protease enzyme has lot of commercial applications, so the cost-effective production of protease using sunflower oil seed waste was carried out from Oerskovia xanthineolyitca NCIM 2839. The maximum protease production was after 24 h of incubation with 2.5 % oil seed waste concentration. O. xanthineolytica was found to produce two proteases-P1 and P2. The proteases were purified using 60 % cold acetone precipitation and DEAE-cellulose ion exchange chromatography. SDS-PAGE revealed molecular weight of P1 and P2 was 36 and 24 kDa, respectively...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330188/purification-and-characterization-of-a-surfactant-compatible-lipase-from-aspergillus-tamarii-jgif06-exhibiting-energy-efficient-removal-of-oil-stains-from-polycotton-fabric
#13
Arijit Das, Srividya Shivakumar, Sourav Bhattacharya, Sujina Shakya, S S Swathi
An extracellular lipase with 23,666.66 U/ml/min activity was produced by Aspergillus tamarii JGIF06 under submerged fermentation in mineral salt medium containing coconut oil (2.5 % v/v), tryptone (2 % w/v) and ammonium chloride (2 % w/v), with initial pH of 5 ± 0.2, incubated at 25 °C for 7 days on a rotary shaker at 120 rpm. A 7.9-fold increase in lipase-specific activity was recorded after purification by DEAE Sepharose ion exchange and Sephadex G200 column chromatography. The apparent molecular mass of this enzyme was revealed as 50 kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis...
December 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330182/efficient-single-step-chromatographic-purification-of-recombinant-human-antithrombin-rhat-from-saccharomyces-cerevisiae
#14
Maheswara Reddy Mallu, Sandeep Vemula, Srinivasa Reddy Ronda
Antithrombin (AT) is a glycoprotein that inactivates the several physiological target enzymes of coagulation system. The effect of purification strategies plays a crucial role in getting maximum recovery of yield, purity and biological activity of recombinant human antithrombin (rhAT). In the present work, the task of purifying rhAT from Saccharomyces cerevisiae BY4741 has been carried out using two different approaches such as cross flow filtration (CFF) system and chromatography methods. In the first approach, the protein was concentrated and partially purified through CFF to achieve maximum recovery yield and purity of 87 and 94 %, respectively...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28330086/cloning-expression-purification-and-characterization-of-human-mitochondrial-carbonic-anhydrase-va
#15
Danish Idrees, Sudhir Kumar, Syed Abdul Arif Rehman, Samudrala Gourinath, Asimul Islam, Faizan Ahmad, Md Imtaiyaz Hassan
Carbonic anhydrase VA (CAVA) is a mitochondrial enzyme that catalyzes the reversible hydration of CO2 to produce HCO3(-) and proton. CAV is primarily involved in several biosynthetic processes such as ureagenesis, gluconeogenesis and lipogenesis by providing bicarbonate ion. Here, we report a new strategy for cloning, expression and purification for CAVA in the bacterial system followed by its biophysical characterization. The cDNA of CAVA, a 801 nucleotide long that encodes a 267-amino acid polypeptide of molecular mass of 30-kDa (excluding signal peptide), was sub-cloned in the expression vector pET21c and transformed into Escherichia coli strain BL21 (DE3) for expression...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28328039/reduction-of-metal-adducts-in-oligonucleotide-mass-spectra-in-ion-pair-reversed-phase-chromatography-mass-spectrometry-analysis
#16
Robert E Birdsall, Martin Gilar, Henry Shion, Ying Qing Yu, Weibin Chen
RATIONALE: Electrospray ionization mass spectrometry (ESI-MS)-based techniques commonly used in oligonucleotide analyses are known to be sensitive to alkali metal adduct formation. Adducts directly impact the sensitivity of MS-based analyses as the available charge is distributed across the parent peak and adduct(s). The current study systematically evaluated common liquid chromatography (LC) components in LC/ESI-MS configurations used in oligonucleotide analysis to identify metal adduct contributions from LC instrumentation...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28328035/%C3%AE-elimination-coupled-with-strong-cation-exchange-chromatography-for-phosphopeptide-analysis
#17
Hansuk Buncherd, Winfried Roseboom, Daranee Chokchaichamnankit, Phannee Sawangareetrakul, Amornrat Phongdara, Chantragan Srisomsap, Luitzen de Jong, Jisnuson Svasti
RATIONALE: Since the last decade, mass spectrometry (MS) has become an essential technique for phosphoprotein analysis. Formidable analytical challenges of MS for phosphoprotein study are both the low abundance of phosphopeptides and the lack of an unambiguous diagnostic fragment ion for identification of phospho residues. These challenges can be met by a charge-based isolation of β-elimination products after tryptic digestion using diagonal strong cation-exchange chromatography. METHODS: β-Elimination combined with diagonal strong cation-exchange chromatography (BE/2SCX) was used for the enrichment of phosphorylated peptides prior to a mass spectrometric analysis by liquid chromatography/ion trap tandem mass spectrometry (MS/MS)...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28328020/detection-of-glutathione-conjugates-of-amiodarone-and-its-reactive-diquinone-metabolites-in-rat-bile-using-mass-spectrometry-tools
#18
Keyur R Parmar, Shalu Jhajra, Saranjit Singh
RATIONALE: Amiodarone is reported to cause hepato and pulmonary toxicity in humans, which has been envisaged to be due to formation of its reactive metabolites, essentially based on its structural similarity to benzbromarone, a drug withdrawn from the market due to reasons of similar hepatotoxicity. Therefore, the purpose of this study was to detect glutathione conjugates of amiodarone and its reactive diquinone metabolites in rat bile using mass spectrometry tools. METHODS: Wistar rats were dosed orally with an amiodarone suspension and bile was collected via bile duct cannulation followed by solid-phase extraction, protein precipitation and centrifugation...
May 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28324833/simplified-purification-approach-of-urinary-neutrophil-gelatinase-associated-lipocalin-by-tangential-flow-filtration-and-ion-exchange-chromatography
#19
Kunal K Shukla, Shamkant B Badgujar, Paresh B Bhanushali, Sushma G Sabharwal
This investigation reports a simplified approach for the purification of urinary siderocalin known as neutrophil gelatinase-associated lipocalin (NGAL). Urinary NGAL was purified by tangential flow filtration and ion exchange chromatography. Isolated NGAL was analyzed by SDS-PAGE, immunoblotting and mass spectrometry (MS). The relative molecular mass of NGAL is 23674Da. Peptide mass fingerprinting of the purified NGAL yielded peptides that partially matched with known sequence of P80188 (NGAL_HUMAN). The tryptic digestion profile of isolated NGAL infers that it may be unique and additive molecule in the dictionary of urinary proteins...
March 11, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28324127/development-of-certified-reference-materials-for-electrolytes-in-human-serum-gbw09124-09126
#20
Liuxing Feng, Jun Wang, Yanjie Cui, Naijie Shi, Haifeng Li, Hongmei Li
Three reference materials, at relatively low, middle, and high concentrations, were developed for analysis of the mass fractions of electrolytes (K, Ca, Na, Mg, Cl, and Li) in human serum. The reference materials were prepared by adding high purity chloride salts to normal human serum. The concentration range of the three levels is within ±20% of normal human serum. It was shown that 14 units with duplicate analysis is enough to demonstrate the homogeneity of these candidate reference materials. The statistical results also showed no significant trends in both short-term stability test for 1 week at 40 °C and long-term stability test for 14 months...
March 21, 2017: Analytical and Bioanalytical Chemistry
keyword
keyword
97204
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"