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https://www.readbyqxmd.com/read/28633848/novel-synthesis-of-nanocomposite-for-the-extraction-of-sildenafil-citrate-viagra-from-water-and-urine-samples-process-screening-and-optimization
#1
Arash Asfaram, Mehrorang Ghaedi, Mihir Kumar Purkait
A sensitive analytical method is investigated to concentrate and determine trace level of Sildenafil Citrate (SLC) present in water and urine samples. The method is based on a sample treatment using dispersive solid-phase micro-extraction (DSPME) with laboratory-made Mn@ CuS/ZnS nanocomposite loaded on activated carbon (Mn@ CuS/ZnS-NCs-AC) as a sorbent for the target analyte. The efficiency was enhanced by ultrasound-assisted (UA) with dispersive nanocomposite solid-phase micro-extraction (UA-DNSPME). Four significant variables affecting SLC recovery like; pH, eluent volume, sonication time and adsorbent mass were selected by the Plackett-Burman design (PBD) experiments...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28633843/ultrasound-assisted-dispersive-magnetic-solid-phase-extraction-for-preconcentration-and-determination-of-trace-amount-of-hg-ii-ions-from-food-samples-and-aqueous-solution-by-magnetic-graphene-oxide-fe3o4-go-2-ptsc-central-composite-design-optimization
#2
Akram Keramat, Rouholah Zare-Dorabei
In this work, the synthesis of the magnetic graphene oxide modified by 2-pyridinecarboxaldehyde thiosemicarbazone groups (Fe3O4@GO/2-PTSC) was utilized for preconcentration and determination of mercuric ions in a trace amount by inductively coupled plasma-optical emission spectrometry (ICP-OES). Characterization of the adsorbent was performed using various techniques, such as FT-IR, VSM, SEM and XRD analysis. Central composite design (CCD) under response surface methodology (RSM) was used for obtaining the most important parameters and probable interactions in variables...
September 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28631113/fast-determination-of-ingredients-in-solid-pharmaceuticals-by-microwave-enhanced-in-source-decay-of-microwave-plasma-torch-mass-spectrometry
#3
Rui Su, Xinchen Wang, Changming Hou, Meiling Yang, Keke Huang, Huanwen Chen
Rapid qualitative and quantitative analysis of solid samples (e.g., pharmaceutical preparations) by using a small and low-resolution mass spectrometer without MS/MS function is still a challenge in ambient pressure ionization mass spectrometric analysis. Herein, a practically efficient method termed microwave-enhanced in-source decay (MEISD) using microwave plasma torch desorption ionization coupled with time-of-flight mass spectrometry (MPTDI-TOF MS) was developed for fast analysis of pharmaceutical tablets using a miniature TOF mass spectrometer without tandem mass function...
June 19, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28629936/logit-log-evaluation-of-planar-yeast-estrogen-screens
#4
Dinah Schick, Wolfgang Schwack
Receptor assays like the yeast estrogen screen (YES) performed in microtiter plates normally provide dose-response curves with a sigmoidal shape in semi-log plots. Such sigmoidal plots can be linearized by the logit function resulting in logit-log plots, as mainly known for the evaluation of enzyme-linked immunosorbent assays and radioimmunoassays. Since the planar yeast estrogen screen (pYES) represents the transfer of the receptor assay YES to high-performance thin-layer chromatography (HPTLC), it was assumed to obtain sigmoidal shaped dose-response curves from the measured signals, which subsequently could be used to generate logit-log plots...
June 13, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28628485/free-standing-ag-triangle-arrays-with-configurable-vertical-gap-for-surface-enhanced-raman-spectroscopy
#5
Kuanguo Li, Yong Wang, Kang Jiang, Yuan Ren, Yanqiu Dai, Yonghua Lu, Pei Wang
Large-area ordered arrays with dense hot spots are highly desirable substrates for surface-enhanced Raman scattering (SERS). In this paper, we present a quasi-3D SERS substrate of free-standing Ag triangle arrays (FATA) which was fabricated by nanosphere lithography incorporated with photolithography and Ag covering. Significant SERS effect arises from a strongly enhanced local electric field within the tiny gaps between the suspending Ag triangle and the Ag baseplate. The SERS intensity relative standard deviation (RSD) is less than 7...
June 19, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28623787/simultaneous-determination-of-btex-and-their-metabolites-using-solid-phase-microextraction-followed-by-hplc-or-gc-ms-an-application-in-teeth-as-environmental-biomarkers
#6
Johannes L González, Albert Pell, Montserrat López-Mesas, Manuel Valiente
Applications of benzene, toluene, ethylbenzene, and o-, m-, and p-xylenes (BTEX) release them into the environment exposing living organism. These endocrine disruptors are toxic, highly volatile and easily absorbed by the lungs and can cause adverse consequences for the human health as neurological diseases and cancer. A method for the analysis of BTEX and its metabolites (phenols and aromatic acids) in teeth is presented. The method consists in a one-step simple extraction procedure from spiked tooth using NaOH solution followed by SPME-HPLC or HS-SPME-GC/MS determination...
June 14, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28621728/determination-of-sulfonamide-residues-in-food-by-capillary-zone-electrophoresis-with-on-line-chemiluminescence-detection-based-on-an-ag-iii-complex
#7
Tingting Dai, Jie Duan, Xinghua Li, Xiangdong Xu, Hongmei Shi, Weijun Kang
The presence of sulfonamide (SA) residues in foods is largely due to the raising of animals with sulfonamide antibiotics added or polluted feedstuff. In this paper, a sensitive method was developed for the determination of the residues of three sulfonamides in animal-derived food; the SAs include sulfadimidine (SDD), sulfadiazine (SDZ), and sulfathiazole (STZ). The method is based on capillary zone electrophoresis (CE) with online chemiluminescence (CL) detection, using an Ag(III) complex as an oxidant. These SAs have an inhibiting effect on the Ag(III)-luminol CL reaction...
June 16, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28621487/simultaneous-quantification-of-imatinib-and-its-main-metabolite-n-demethyl-imatinib-in-human-plasma-by-liquid-chromatography-tandem-mass-spectrometry-and-its-application-to-therapeutic-drug-monitoring-in-patients-with-gastrointestinal-stromal-tumor
#8
Wei Zhuang, Hai-Bo Qiu, Xin-Meng Chen, Xiu-Hong Yuan, Li-Fang Yang, Xiao-Wei Sun, Xiao-Jun Zhou, Min Huang, Xue-Ding Wang, Zhi-Wei Zhou
AIM: To improve and validate a more stable and less time-consuming method based on liquid chromatography and tandem mass spectrometry (LC- MS/MS) for the quantitative measurement of Imatinib and its metabolite N-demethyl-Imatinib (NDI) in human plasma. METHODS: Separation of analytes was performed on a Waters XTerra RP18 column (50mm×2.1 mm i.d., 3.5 μm) with a mobile phase consisting of methanol/acetonitrile/ water (65:20:15, v/v/v) with 0.05% formic acid at a flow-rate of 0...
June 16, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28617336/response-surface-optimized-infrared-assisted-extraction-and-uhplc-determination-of-flavonoid-types-from-flos-sophorae
#9
Qianqian Mou, Jingxia He, Rongli Yin, Bin Yang, Meihong Fu, Jing Fang, Hua Li
Single-factor experiment and Box-Behnken design were applied to optimize the infrared-assisted extraction (IRAE) of rutin, quercetin, kaempferol, and isorhamnetin from Flos sophorae. Four factors (extract solvent, solid-liquid ration, extraction time, infrared power) affecting the extraction yield of flavonoids were studied. Under optimized conditions the extraction yield was 33.199 ± 0.24 mg/g, which substantially improved, compared with heating reflux extraction (HRE) and ultrasonic-assisted extraction (UAE), while extraction time was only 9 min...
June 15, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28603124/validation-and-application-of-high-performance-liquid-chromatographic-method-for-the-estimation-of-metoclopramide-hydrochloride-in-plasma
#10
Ahmad Khan, Jallat Khan, Muhammad Irfan, Syed Baqir Shyum Naqvi, Gul Majid Khan, Muhammad Harris Shoaib, Rabia Ismail Yousaf, Amjad Khan
The objective of this study was validation of a reverse phase HPLC method for the estimation of metoclopramide HCl in plasma already validated for determination of metoclopramide HCl in tablets dosage form. A reverse chromatographic method was used for estimation of metoclopramide HCl with the mobile phase of acetonitrile, 20mM potassium dihydrogen phosphate buffer solution (pH 3.0 adjusted with orthophosphoric acid) in the ratio of 40: 60. The column used was Waters C18 3.9×300mm µBondapak (RP). The flow rate of the mobile phase was 2ml/ minute...
January 2017: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28603108/a-validated-stability-indicating-rp-hplc-method-for-estimation-of-armodafinil-in-pharmaceutical-dosage-forms-and-characterization-of-its-base-hydrolytic-product
#11
Kambham Venkateswarlu, Ardhgeri Rangareddy, Kanaka Narasimhaiah, Hemraj Sharma, Naga Mallikarjuna Raja Bandi
The main objective of present study was to develop a RP-HPLC method for estimation of Armodafinil in pharmaceutical dosage forms and characterization of its base hydrolytic product. The method was developed for Armodafinil estimation and base hydrolytic products were characterized. The separation was carried out on C18 column by using mobile phase as mixture of water and methanol (45:55%v/v). Eluents were detected at 220nm at 1ml/min. Stress studies were performed with milder conditions followed by stronger conditions so as to get sufficient degradation around 20%...
January 2017: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28602302/fabrication-of-porous-ionic-liquid-polymer-as-solid-phase-microextraction-coating-for-analysis-of-organic-acids-by-gas-chromatography-mass-spectrometry
#12
Zhentao Tang, Yixiang Duan
A kind of porous ionic liquid polymer was designed as coating material for solid-phase microextraction (SPME) fibers to extract polar organic acids. The synthesized ionic liquids (1-vinyl-3-(4-vinyl-benzyl)imidazolium chloride) were polymerized in the presence of azobisisobutyronitrile (AIBN), and subsequently coated on stainless steel wires with physical adhesion. To guarantee the adhesion between coating and the surface of stainless steel wires, micro-wave induced plasma was applied to modify the stainless steel wires...
September 1, 2017: Talanta
https://www.readbyqxmd.com/read/28602290/a-sensitive-and-disposable-electrochemical-immunosensor-for-detection-of-sox2-a-biomarker-of-cancer
#13
Elif Burcu Aydın, Mustafa Kemal Sezgintürk
A novel, sensitive, disposable indium tin oxide (ITO)-based electrochemical immunosensor was developed firstly for simple, rapid determination of Sex-determining region Y-box 2 (SOX2). SOX2 is a cancer biomarker and used for detecting small cell lung cancer, lung adenocarcinoma, squamous cell carcinoma, skin cancer, prostate cancer, and breast cancer. In this study, a disposable ITO thin film based electrode was used as working electrode for biosensing the interaction between SOX2 antigen and anti-SOX2 antibody...
September 1, 2017: Talanta
https://www.readbyqxmd.com/read/28601766/trace-level-determination-of-5-hydroxytryptamine-and-its-related-indoles-in-amniotic-fluid-by-gas-chromatography-mass-spectrometry
#14
Hongmei Shi, Bo Wang, Lingmei Niu, Mengsi Cao, Weijun Kang, Kaoqi Lian, Pingping Zhang
5-hydroxytryptamine (5-HT) and its derivatives are endogenously active substances involved in multiple physiological and pathological processes. A novel method of detetermining 5-hydroxyindole ethanol (5-HTOL), 5-hydroxyindole acetic acid (5-HIAA), 5-hydroxytryptophan (5-HTP) and 5-HT in amniotic fluid by gas chromatography-mass spectrometry (GC-MS) was established based on a modified method of derivatization by silanization, in combination with solid-phase extraction pretreatment. Good linearity was achieved in the tested calibration range...
June 3, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28601363/evaluation-of-uncertainty-sources-in-the-determination-of-testosterone-in-urine-by-calibration-based-and-isotope-dilution-quantification-using-ultra-high-performance-liquid-chromatography-tandem-mass-spectrometry
#15
J Pitarch-Motellón, A F Roig-Navarro, J V Sancho, M Ibáñez, N Fabregat-Cabello, O J Pozo, Rosa Ventura, J I García Alonso, Pablo Rodríguez-González, Adriana González Gago, Amaia Ereño Artabe, Peter Van Eenoo, Koen Deventer, Yvette Dehnes, Sebastian Rzeppa
Three quantification methodologies, namely calibration with internal standard (Cal-IS, non-weighted), weighted calibration with internal standard (wCal-IS) and isotope pattern deconvolution (IPD) have been used for the determination of testosterone in urine by LC-MS/MS. Uncertainty has been calculated and compared for the three methodologies through intra- and inter-laboratory reproducibility assays. IPD showed the best performance for the intra-laboratory reproducibility, with RSD and combined uncertainty values below 4% and 9% respectively...
June 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28600692/simultaneous-determination-of-pyrethroids-and-pyrethrins-by-dispersive-liquid-liquid-microextraction-and-liquid-chromatography-triple-quadrupole-mass-spectrometry-in-environmental-samples
#16
Alexander Ccanccapa-Cartagena, Ana Masiá, Yolanda Picó
A simple and environmentally friendly dispersive liquid-liquid microextraction (DLLME) method coupled with electrospray ionization liquid chromatography triple quadrupole mass spectrometry (LC-QqQ-MS/MS) was developed for the simultaneous determination of 17 synthetic and natural pyrethroids. A comparison of solid-phase extraction (SPE) versus DLLME for water samples and only "dilute and shoot" versus the additional extract cleanup by DLLME for sediment samples is reported. Chloroform was the extracting solvent in the DLLME technique for both water and sediment samples...
June 10, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28599860/molecularly-imprinted-nanoparticles-grafted-to-porous-silica-as-chiral-selectors-in-liquid-chromatography
#17
Raquel Gutierrez-Climente, Alberto Gomez-Caballero, Antonio Guerreiro, Deiene Garcia-Mutio, Nora Unceta, M Aránzazu Goicolea, Ramon J Barrio
The work presented here explores the grafting of molecularly imprinted nanoparticles (MIN) on silica beads for the development of new chiral stationary phases (CSP). Both solid-phase imprinting and precipitation polymerisation were tested for MIN synthesis though the latter approach was the only one that provided efficient chiral selectors. MIN particles were prepared by iniferter polymerisation initiated by UV radiation, using itaconic acid as functional monomer and ethylene dimethacrylate as cross-linker...
June 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28597970/simultaneous-determination-of-eight-short-chain-aliphatic-amines-in-drug-substances-by-hplc-with-diode-array-detection-after-derivatization-with-halonitrobenzenes
#18
Lingfei Han, Desheng Hou, Congyu Ma, Na Fu, Jing Liu, Feng Feng, Wenyuan Liu, Feng Zheng
Short-chain aliphatic amines are a class of hazardous impurities in drug substances. A simple method, involving derivatization followed by high-performance liquid chromatography with diode array detection, has been developed for residue determination of eight aliphatic amines simultaneously in drug substances. Different halonitrobenzenes derivatization reagents were systematically compared. As a result, 1-fluoro-2-nitro-4-(trifluoromethyl)benzene was selected since the derivatization effectively shifted the absorption wavelength to the visible region (400-450 nm), where most drug substances, impurities and even the derivatization reagent absorb very weakly...
June 8, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28595724/sol-gel-coated-ion-sources-for-liquid-chromatography-direct-electron-ionization-mass-spectrometry
#19
Nicolò Riboni, Laura Magrini, Federica Bianchi, Maria Careri, Achille Cappiello
Advances in interfacing liquid chromatography and electron ionization mass spectrometry are presented. New ion source coatings synthesized by sol-gel technology were developed and tested as vaporization surfaces in terms of peak intensity, peak width and peak delay for the liquid chromatography-direct electron ionization mass spectrometry (Direct-EI) determination of environmental pollutants like polycyclic aromatic hydrocarbons and steroids. Silica-, titania-, and zirconia-based coatings were sprayed inside the stainless steel ion source and characterized in terms of thermal stability, film thickness and morphology...
July 25, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28593189/formulation-and-development-of-a-validated-uv-spectrophotometric-analytical-method-of-rutin-tablet
#20
Murad N Abualhasan, Jumana Mansour, Nidal Jaradat, Abdel Naser Zaid, Ibrahim Khadra
Rutin is available in some foods, fruits, and vegetables. It has various beneficial medical effects making it useful in the treatment of various diseases. Rutin is available in different oral dosage forms such as tablets or capsules, widely available in the market. Rutin and many herbal medicines lack quality control due to unavailability of analytical methods. In this study, we formulated rutin tablet and studied its stability using a simple developed analytical method. The dissolution profile of our formulated tablet was also inspected...
2017: International Scholarly Research Notices
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