keyword
MENU ▼
Read by QxMD icon Read
search

Rsd

keyword
https://www.readbyqxmd.com/read/28936848/-simultaneous-determination-of-seven-alkaloids-and-three-flavonoids-in-sophorae-tonkinensis-radix-et-rhizoma-by-hplc
#1
Fu-Man Han, Li-Xin Wang, Ying Chen, Liang-Mian Chen, Wei-Hong Feng, Jin-Yu Wang, De-Wen Liu, Yun You, Yan Tong
In this study, an HPLC method was developed for simultaneous determination of seven alkaloids (cytosine, oxymatrine, N-oxysophocarpine, N-methylcytisine, sophoranol, matrine, and sophocarpine) and three flavonoids (trifolirhizin, fermononetin, and maackiain) from different samples of Sophorae Tonkinensis Radix et Rhizoma. Samples were analyzed on a Welch XtimateTM C₁₈ column (4. 6 mm× 250 mm, 5 μm) eluted with the mobile phase of acetonitrile (A) and 0.01 mol•L⁻¹ ammonium acetate solution (pH 8.0) (B) in a linear gradient mode as follows: 0-20 min,4%-14% A;20-30 min,14%-25% A;30-45 min,25%-40% A;45-65 min,40%-55% A;65-75 min,55% A...
December 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28936841/-determination-of-six-alkaloids-in-six-types-of-coptidis-rhizoma-pieces-by-rp-hplc-and-spectrum-effect-relationships-with-anti-diabetes-pharmacodynamics-data
#2
Xian-Rong Lai, Bang-Hua Zhou, Ming-Sheng Du, Hai-Jie Zheng, Zhi-Peng Geng, Jia-Chuan Li, Xian-Li Meng, Yi Zhang, Jing Zhang
To establish a method for determining the contents of six alkaloids (jatrorrhizine hydrochloride, columbamine hydrochloride, epiberberine hydrochloride, coptisine hydrochloride, palmatine hydrochloride, berberine hydrochloride) in six types of Coptidis Rhizoma pieces (crude pieces, ginger juice stir-fried pieces, vinegar stir-fried pieces, wine steamed pieces, wine stir-fried pieces, evodiae juice stir-fried pieces) by RP-HPLC, and explore the relationship with the curative effect of traditional Chinese medicine (TCM) and pharmacodynamics results...
December 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28934999/vortex-assisted-modified-dispersive-liquid-liquid-microextraction-of-trace-levels-of-cadmium-in-surface-water-and-groundwater-samples-of-tharparkar-pakistan-optimized-by-multivariate-technique
#3
Sooraj Nizamani, Tasneem G Kazi, Hassan I Afridi, Sehrish Talpur, Ayaz Lashari, Anjum Lashari, Jamshed Ali
A simple vortex-assisted modified dispersive liquid–liquid microextraction procedure is proposed forthe enrichment of cadmium (Cd(+2)) in surface (stored rainwater) and groundwater of the Tharparkar district in Pakistan, before analysis by flame atomic absorption spectrometry. Ammonium pyrrolidinedithiocarbamate was used as a ligand to make a hydrophobic complex of Cd(+2), which was extracted in an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate), and the nonionic surfactant Triton X-114 was applied as a dispersing medium...
September 21, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28934998/determination-of-phosphine-residues-in-wheat-and-yellow-corn-with-a-new-developed-method-using-headspace-and-sim-mode-gc-ms
#4
Tamer M A M Thabit, Dalia I H Elgeddawy
Phosphine is considered the main fumigant material used for long time for controlling insect pests in stored grains. This research was focused on the determination of phosphine residues in cereal matrices (mainly wheat and corn) after the fumigation process, using a new procedure developed to reduce the number of analytical steps and improve the chromatographic separation, identification, and quantitation of analyte, thus leading to enhanced total efficiency and sensitivity. This method, using gastight vials for extraction with 5% sulfuric acid, a heating extraction sequence, and injection with headspace and GC-MS in selected-ion monitoring mode, gave clean separation and accurate results...
September 22, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28934031/simultaneous-detection-of-15-antibiotic-growth-promoters-in-bovine-muscle%C3%AF-blood-and-urine-by-uplc-ms-ms
#5
Zhi Wang, Zongwei Shi, Cunxian Xi, Guomin Wang, Shurui Cao, Lei Zhang, Bobin Tang, Zhaode Mu
An analytical method was established for the rapid detection of antibiotic growth promoters (AGPs) in bovine muscle, and bovine blood and bovine urine, using ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). After the addition of an aqueous solution of EDTA-Na2, the pH of bovine urine samples was directly adjusted to 5.2 by acetic acid-ammonium acetate and purified by HLB solid-phase extraction cartridge; bovine muscle and bovine blood samples processing were extracted with acetonitrile (ACN) and ACN-water (90:10; v/v) without any purification step...
September 21, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28929691/-deuterated-surrogate-and-uplc-ms-ms-method-for-simultaneous-determination-of-22-endocannabinoids-in-ovariectomized-rat-plasma
#6
Shi-Xie Xiang, Ying Xu, Jing-Jing Zhu, Zhi-Min Wang, Dong Zhang, Liang-Mian Chen, Wei-Hong Feng
A new method based on ultraperformance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for the simultaneous determination of 22 endocannabinoids(eCBs) and relevant compounds in ovariectomized rat plasma. After being extracted by solid-phase column(SPE), the plasma samples were detected by using UPLC-MS/MS. Analysis was carried out with ACQUITY UPLC BEH C₁₈ column. The mobile phase was 0.1% acetic acid solution(A)-acetonitrile and isopropanol(9∶1, B) for the gradient elution. In the positive ion multiple reaction monitoring(MRM) mode, deuterated reagents were taken as standard alternatives to calculate recoveries and simultaneously quantify 22 endocannabinoids...
November 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929685/-simultaneous-determination-of-8-main-compounds-in-eclipta-herba-by-uplc
#7
Xue-Feng Hou, Shuai Sun, Gang Wang, Hui-Hui Qiu, Shu-Min Ding, Ying Liu, Dan Liu, Liang Feng, Xiao-Bin Jia
To establish an UPLC method for the simultaneous determination of 8 compounds in Eclipta Herba, such as isoquercitrin, luteoloside, demethylwedelolactone, isochlorogenic acid A, isochlorogenic acid C, luteolin, wedelolactone and apigenin. The experiment was performed with a Waters Acquity UPLC BEH C₁₈ (2.1 mm×100 mm, 1.7 μm) column by gradient elution of 0.1% formic acid in water and acetonitrile: 0-4 min,10%-13% A; 4-10 min, 13%-16% A; 10-13 min, 16%-25% A; 13-17 min, 25%-28% A; 17-20 min,28%-40% A;20-25 min,40%-95% A...
November 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929655/-a-semimicroquality-evaluation-method-on-panax-notoginseng-and-its-application-in-analysis-of-continuous-cropping-obstacles-research-samples
#8
Yi Cao, Chao-Qun Wang, Feng Xu, Xiu-Hong Jia, Guang-Xue Liu, Sheng-Chao Yang, Guang-Qiang Long, Zhong-Jian Chen, Fu-Zhou Wei, Shao-Zhou Yang, Kozo Fukuda, Xuan Wang, Shao-Qing Cai
Panax notoginseng is a commonly used traditional Chinese medicine with blood activating effect while has continuous cropping obstacle problem in planting process. In present study, a semimicroextraction method with water-saturated n-butanol on 0.1 g notoginseng sample was established with good repeatability (RSD<2.5%) and 9.6%-20.6% higher extraction efficiency of seven saponins than the conventional method. A total of 16 characteristic peaks were identified by LC-MS-IT-TOF, including eight 20(S)-protopanaxatriol (PPT) type saponins and eight 20(S)-protopanaxadiol (PPD) type saponins...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28927936/rapid-quantitative-detection-of-glucose-content-in-glucose-injection-by-reaction-headspace-gas-chromatography
#9
Wei-Qi Xie, Yi-Xian Gong, Kong-Xian Yu
This work investigates an automated technique for rapid detecting the glucose content in glucose injection by reaction headspace gas chromatography (HS-GC). This method is based on the oxidation reaction of glucose in glucose injection with potassium dichromate. The carbon dioxide (CO2) formed from the oxidation reaction can be quantitatively detected by GC. The results show that the relative standard deviation (RSD) of the present method was within 2.91%, and the measured glucose contents in glucose injection closely match those quantified by the reference method (relative differences <6...
September 8, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28927490/development-and-validation-of-an-analytical-method-readily-applicable-for-quality-control-of-tabebuia-impetiginosa-taheebo-ethanolic-extract
#10
Yan Jin, Kyung Min Jeong, Jeongmi Lee, Jing Zhao, Su-Young Choi, Kwang-Soo Baek
The dried inner bark of Tabebuia impetiginosa, known as taheebo or red lapacho, has numerous beneficial effects on human health. This study presents the first simple and reliable quantitative method that could serve for the QC of taheebo. The method uses LC–UV spectroscopy to determine the veratric acid (VA; 3,4-dimethoxybenzoic acid) content of taheebo extracts (TEs). Sample preparation entailed the dissolution of TE in methanol (MeOH), facilitated by ultrasonic radiation for 10 min. The optimized conditions included chromatographic separation on an Agilent Eclipse Plus C18 column (4...
September 19, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28927487/ultrasonically-dispersed-ionic-liquid-based-microextraction-of-lead-in-biological-samples-of-malnourished-children-prior-to-analysis-by-flame-atomic-absorption-spectrometry
#11
Sehrish Talpur, Tasneem Gul Kazi, Hassan Imran Afridi, Farah Naz Talpur, Sooraj Nizamani, Anjum Lashari, Asma Akhtar, Mustafa Khan
In the present study, a simple ultrasonically dispersed modified liquid-phase microextraction method was developed for the extraction of lead (Pb) from blood and scalp hair samples of malnourished children (MNC). The complexation of Pb was executed by means of the complexing agent, ammonium pyrrolidinedithiocarbamate (APDC), whereas extraction was carried out through the ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate. Ultrasound energy was used for the dispersion and extraction of the metal complex into an IL because it enhances the extraction of the metal complex into infinite IL drops at a temperature range of 40–80°C for 1–5 min...
September 19, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28926698/quantification-of-lignin-and-its-structural-features-in-plant-biomass-using-13-c-lignin-as-internal-standard-for-pyrolysis-gc-sim-ms
#12
Gijs van Erven, Ries de Visser, Donny W H Merkx, Willem Strolenberg, Peter De Gijsel, Harry Gruppen, Mirjam A Kabel
Understanding mechanisms underlying plant biomass recalcitrance at molecular level can only be achieved by accurate analyses of both content and structural features of the molecules involved. Current quantification of lignin is, however, majorly based on unspecific gravimetric analysis after sulphuric acid hydrolysis. Hence, our research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric (13)C lignin was used as internal standard (IS) for lignin quantification via analytical pyrolysis coupled to gas chromatography with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS)...
September 19, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28926582/selection-of-possible-signature-peptides-for-the-detection-of-bovine-lactoferrin-in-infant-formulas-by-lc-ms-ms
#13
Mingmei Yuan, Cong Feng, Shouyun Wang, Weiwei Zhang, Mo Chen, Hong Jiang, Xuesong Feng
An LC-MS/MS assay based on a signature peptide was developed and fully validated for the quantitation of bovine lactoferrin in infant formulas. Three unreported signature peptides were derived and identified from the tryptic peptides of bovine lactoferrin. The peptide ETTVFENLPEK was used for quantification based on assay performance. The blank matrix camel milk powder and bovine lactoferrin protein standards were mixed and spiked with stable isotope-labeled internal standard to establish a calibration curve...
2017: PloS One
https://www.readbyqxmd.com/read/28921606/dynamic-residual-pattern-of-azoxystrobin-in-swiss-chard-with-contribution-to-safety-evaluation
#14
Waziha Farha, A M Abd El-Aty, Md Musfiqur Rahman, Md Humayun Kabir, Hyung Suk Chung, Han Sol Lee, Jong-Sup Jeon, Jing Wang, Byung-Joon Chang, Ho-Chul Shin, Jae-Han Shim
This study aimed at quantifying the residual amount of azoxystrobin in Swiss chard samples grown under greenhouse conditions at 2 different locations (Gwangju and Naju, Republic of Korea). Samples were extracted with acetonitrile, separated by salting out, and subjected to purification by using solid-phase extraction (SPE). The analyte was identified using liquid chromatography (LC)-ultraviolet detector (UVD). The linearity of the calibration range was excellent with coefficient of determination (R(2) ) =1...
September 15, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28918593/decline-patterns-and-risk-assessment-of-10-multi-class-pesticides-in-young-sprout-amaranth-amaranthus-mangostanus-under-greenhouse-growing-conditions
#15
In Kyung Kim, Sung-Woo Kim, A M Abd El-Aty, Md Musfiqur Rahman, Md Humayun Kabir, Han Sol Lee, Hyung Suk Chung, Ji Hoon Jeong, Ho-Chul Shin, Jae-Han Shim
The present study was designed to investigate the residual decline pattern and the risk assessment of 10 different class pesticides, namely azoxystrobin, boscalid, diazinon, diethofencarb, difenoconazole, etofenprox, flubendiamide, paclobutrazol, and pyraclostrobin in young vegetative amaranth (Amaranthus mangostanus) sprayed once or twice under greenhouse growing conditions. Field-incurred samples, collected at 3, 7, or 10 days after application of both treatments, were extracted and purified with the quick, easy, cheap, effective, rugged, and safe "QuEChERS" citrate-buffered method and analyzed with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS) in positive ion mode...
September 16, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28918327/determination-of-ketamine-and-its-main-metabolites-by-liquid-chromatography-coupled-to-tandem-mass-spectrometry-in-pig-plasma-comparison-of-extraction-methods
#16
Cindy Ramiole, Benoit D'Hayer, Vincent Boudy, Josette Legagneux, Julien Fonsart, Pascal Houzé
A rapid, sensitive and specific liquid chromatography coupled to tandem mass spectrometry method was developed for the simultaneous quantification pig plasma of ketamine and its two principal metabolites, norketamine and dehydronorketamine. Three extraction procoles were assessed including acetonitrile precipitation, Oase™ microplate extraction, and liquid-liquid extraction. Oase™ microplate extraction induced no significant matrix effect, important signal/noise ratio and good recoveries, ranging from 82 to 87% for the considered compounds...
September 8, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28918325/a-novel-lc-ms-ms-method-for-the-quantitative-measurement-of-the-acetate-content-in-pharmaceutical-peptides
#17
Rani J Qasem, Ibrahim K Farh, Mohammed A Al Essa
Most pharmaceutical peptides are supplied as acetate salts and the relative amount of acetate to peptide in the final product is one quality criterion required by regulatory agencies to approve the product for clinical use. The objective of the present study was to develop a validated LC-MS/MS method that allows the quantitative determination of the acetate content in pharmaceutical peptide preparations and simultaneous monitoring and collection of qualitative and quantitative information on the peptide during manufacture and in the final product...
September 6, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28917749/trace-determination-of-volatile-polycyclic-aromatic-hydrocarbons-in-natural-waters-by-magnetic-ionic-liquid-based-stir-bar-dispersive-liquid-microextraction
#18
Juan L Benedé, Jared L Anderson, Alberto Chisvert
In this work, a novel hybrid approach called stir bar dispersive liquid microextraction (SBDLME) that combines the advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) has been employed for the accurate and sensitive determination of ten polycyclic aromatic hydrocarbons (PAHs) in natural water samples. The extraction is carried out using a neodymium stir bar magnetically coated with a magnetic ionic liquid (MIL) as extraction device, in such a way that the MIL is dispersed into the solution at high stirring rates...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28917736/off-line-microextraction-by-packed-sorbent-combined-with-on-solid-support-derivatization-and-gc-ms-application-for-the-analysis-of-five-pyrethroid-metabolites-in-urine-samples
#19
Anna Klimowska, Bartosz Wielgomas
A novel, fast and eco-friendly analytical method using microextraction by packed sorbent coupled to large volume injection-gas chromatography-mass spectrometry (MEPS-LVI-GC-MS) was developed for the determination of five pyrethroid metabolites (cis-2,2-dimethyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-cyclopropanecarboxylic acid, cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acids, cis-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid and 3-phenoxybenzoic acid) in human urine...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28916109/systematic-approach-in-mg-2-ions-analysis-with-a-combination-of-tailored-fluorophore-design
#20
L Lvova, C Guanais Gonçalves, L Prodi, M Sgarzi, N Zaccheroni, M Lombardo, A Legin, C Di Natale, R Paolesse
A systematic study of a series of diaza-18-crown-6 8-hydroxyquinoline (DCHQ) chemosensors, devoted to Mg(II) ion detection, was performed. Functionalization of DCHQ by peripheral substituents allowed the development of novel all-solid-state optodes via inclusion inside PVC-based polymeric films. The influence on the DCHQ-based optode response of the lipophilic sites functionalization and of the nature of the plasticizer, was investigated. Fluorimetric studies on optodes sensitivity towards a number of different metal cations (Ca(2+), Na(+), K(+), Li(+), Co(2+), Cd(2+), Pb(2+), Cu(2+), Hg(2+), Zn(2+)) and NH4(+) were carried out...
October 2, 2017: Analytica Chimica Acta
keyword
keyword
750
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"