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Journal of Chromatographic Science

Vasanti M Suvarna, Preeti C Sangave
Darunavir ethanolate (DRV) is an efficient protease inhibitor (PI) used in the treatment of human immunodeficiency virus (HIV) type-1 patients. An isocratic reversed-phase HPLC method was developed to monitor concentration of darunavir in in vitro intestinal fluid samples in everted sac absorption model in the presence of bioenhancers, viz., piperine, quercetin, naringenin. The method was validated and successfully applied to everted sac and pharmacokinetic studies in rats. The absorption profiles of DRV and apparent permeability coefficients were determined...
January 12, 2018: Journal of Chromatographic Science
Maha M Abdelrahman, Ibrahim A Naguib, Mohamed R El Ghobashy, Nesma A Ali
Two accurate, sensitive and highly selective stability-indicating methods are developed and validated for simultaneous determination of Agomelatine (AGM) and its forced degradation products (Deg I and II). The first method is High-Performance Liquid Chromatography for separation and quantitation of AGM, Deg I and II on a C18 column (250 mm × 4.6 mm, 5 μm p.s) in isocratic mode by using a binary mixture of Potassium dihydrogen phosphate (0.05 M, pH adjusted to 2.9 with orthophosphoric acid): acetonitrile (60:40, v/v) at a flow rate of 2 mL/min...
January 12, 2018: Journal of Chromatographic Science
Francisco Oiram Filho, Daniel Barbosa Alcântra, Tigressa Helena Soares Rodrigues, Lorena Mara Alexandre E Silva, Ebenezer de Oliveira Silva, Guilherme Julião Zocolo, Edy Sousa de Brito
Cashew nut shell liquid (CNSL) contains phenolic lipids with aliphatic chains that are of commercial interest. In this work, a chromatographic method was developed to monitor and quantify anacardic acids (AnAc) in CNSL. Samples containing AnAc were analyzed on a high-performance liquid chromatograph coupled to a diode array detector, equipped with a reversed phase C18 (150 × 4.6 mm × 5 μm) column using acetonitrile and water as the mobile phase both acidified with acetic acid to pH 3.0 in an isocratic mode (80:20:1)...
December 29, 2017: Journal of Chromatographic Science
Qiang Zhou, He Yan, Rui Li, Xingliang Li, Jingyan Wei
1,6-O,O-Diacetylbritannilactone is a natural sesquiterpene lactone isolated from Inula britannica that has displayed cytotoxic effects against several human cancer cell lines. In this study, a selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed for determination of 1,6-O,O-diacetylbritannilactone in rat plasma. Chromatographic separation was achieved on an Agilent C18 column (4.6 mm × 75 mm, 3.5 μm) with methanol and water (80:20, v/v) as the mobile phase...
December 29, 2017: Journal of Chromatographic Science
Rania A Sayed, Manal M El-Masri, Wafaa S Hassan, Magda Y El-Mammli, Abadalla Shalaby
Two novel stability-indicating TLC densitometric and chemometric methods were developed for the determination of mometasone furoate (MF) in the presence of its alkaline degradation product (MF Deg). The developed TLC densitometric method (Method A) is based on the quantitative densitometric separation of MF from its alkaline degradation product on silica gel 60 F254 and measurement of the bands at 250 nm. The separation was carried out using hexane-chloroform-methanol-acetonitrile (6:6:1:0.3, by volume) as a developing system...
December 29, 2017: Journal of Chromatographic Science
Thomas S Thompson, Johan P van den Heever, Stephen F Pernal
Dicyclohexylamine (DCH) is an excipient present in commercial formulations of fumagillin (Fumagilin-B® and Fumidil-B®), an antibiotic which is employed in apiculture for the control of nosema disease. DCH has been demonstrated to be stable in harvested honey; however, its fate in the beehive has not been investigated. In this study, DCH residues were determined in beeswax samples collected from brood chambers and honey supers from various apiaries throughout Alberta. The determination of DCH was performed using a simple extraction procedure followed by low-temperature cleanup and finally analysis with aqueous normal phase liquid chromatography-electrospray ionization tandem mass spectrometry...
December 29, 2017: Journal of Chromatographic Science
Murali Krishna V V N Mantripragada, Sumathi V Rao, Venugopal V S Nutulapati, Bhaskara P V Mantena
A simple, rapid, selective and stability indicating reversed phase-ultra performance liquid chromatography method was developed and validated for the simultaneous quantification of process related and degradation impurities present in Atazanavir and Ritonavir tablets. The two proposed drug components and their respective impurities were separated using Acquity BEH C18 (100 mm × 2.1 mm), 1.7 μ column at a flow rate of 0.4 mL/min. Buffer used as Mobile phase-A which consists of 0.01 M monobasic potassium hydrogen phosphate adjusted the pH to 3...
December 29, 2017: Journal of Chromatographic Science
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December 26, 2017: Journal of Chromatographic Science
Maha M Abdelrahman, Ibrahim A Naguib, Mohamed A Elsayed, Hala A Zaazaa
Two accurate, precise and sensitive high-performance thin layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC) methods were developed for assay of ampicillin (AMP) and dicloxacillin (DX) in the presence of their impurity, 6-aminopenicillanic acid (APA). Method (A) is HPTLC method; using silica gel HPTLC F254 plates as a stationary phase with methanol: chloroform: acetic acid (1:9: 0.2, by volume) as a developing system. All the bands were scanned at 220 nm. Method (B) is reversed phase- HPLC which depended on isocratic elution using C18 column and mobile phase consisting of acetonitrile: water (60:40, v/v), pH adjusted to 4 with orthophosphoric acid, at a flow rate of 1 mL min-1 and ultraviolet detection at 240 nm...
December 15, 2017: Journal of Chromatographic Science
Yanfei Tao, Shuyu Xie, Yufei Zhu, Dongmei Chen, Yuanhu Pan, Xu Wang, Zhenli Liu, Lingli Huang, Dapeng Peng, Zonghui Yuan
A quantitative LC-MS/MS method has been developed for simultaneous determination of bacitracin A, bacitracin B, colistin A, colistin B and virginiamycin M1 in feed. This rapid simple and effective extraction method was based on matrix solid-phase dispersion. Qualitative and quantitative analyses were performed by LC-ESI-MS/MS. CCβ of polypeptide antibiotics upon the method ranged from 9.6 to 15.8 μg kg-1 and 19.4 to 27.5 μg kg-1, respectively. The limit of quantification of polypeptide antibiotics was 25 μg kg-1 in feed samples...
December 13, 2017: Journal of Chromatographic Science
Jin Young Lee
O-ethyl S-2-diisopropylaminoethyl methyl phosphonothiolate (VX) is a highly toxic chemical warfare agent because it inhibits cholinesterase (ChE) activity in the nervous system. Inhibition of butyrylcholinesterase (BChE) activity by VX is due to formation of a phosphorylated BChE adduct; this adduct in human plasma can serve as a biomarker of exposure to nerve agents. We compared purification efficiency between the procainamide affinity gel method and immunomagnetic separation (IMS) for the nerve agent adduct of BChE in plasma and then optimized the sample preparation by purifying BChE to measure biomarkers of human exposure to organophosphorus nerve agents...
December 13, 2017: Journal of Chromatographic Science
Fathalla Belal, Mahmoud A Omar, Sayed Derayea, Mohamed A Hammad, Sahar Zayed, Safaa F Saleh
A simple, sensitive and rapid micellar liquid chromatographic method was developed and validated for simultaneous determination of four drugs, namely, paracetamol (PAR), tizanidine (TZD), aceclofenac (ACF) and nimesulide (NMD). Good chromatographic separation was achieved using Cyano column and micellar mobile phase consisting of 120 mM sodium dodecyl sulfate, 25 mM phosphate buffer and 10% (V/V) butanol. The pH was adjusted to three using phosphoric acid. The total retention time was below 10 min. The analysis was performed at a flow rate of 1 mL/min and a column temperature of 40°C with direct UV detection at 230 nm...
December 11, 2017: Journal of Chromatographic Science
Marta de Diego, Ricardo Godoy, Sigrid Mennickent, Carola Vergara, Daniel Miranda, Pía Navarro
Development, validation and comparison of two stability-indicating LC methods, one with photodiode array detector (DAD) and the other with evaporative light scattering detector (ELSD), were performed for simultaneous determination of candesartan cilexetil (CANC) and hydrochlorothiazide (HCTZ), in pharmaceutical samples. A RP-18 column (125 mm × 4 mm, 5 μm) was used for separation of CANC, HCTZ and its major degradation products, using acetonitrile and phosphate buffer (pH 6.0) for DAD method and acetonitrile and water with acetic acid and triethylamine (pH 4...
December 11, 2017: Journal of Chromatographic Science
Miao-Miao Jin, Wen-Dan Zhang, Geng-Shen Song, Yan-Mei Xu, Ying-Feng Du, Wei Guo, Liang Cao, Hui-Jun Xu
A tissue-smashing based ultra-rapid extraction coupled with ultra-performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS) method was developed to determine 10 major triterpenoid saponins from Pulsatilla herbs. Compound 4 was characterized as betulinic acid glycoside 3-O-α-arabinopyranosyl-28-O-β-glucopyranosyl-23-hydroxy with HR-ESI-MS, 1H-NMR and 13C-NMR experiment. The MS spectra result showed that the ionization of compound 4 was more efficient in the positive mode. Meanwhile, the ions at m/z 789...
December 11, 2017: Journal of Chromatographic Science
Heshuang Dai, Zhiqiong Chen, Bing Shang, Qinhua Chen
A gas chromatographic-mass spectrometric (GC-MS) method was developed for the determination of four anthraquinones found in rhubarb. Chrysophanol, physcion, aloe-emodin and emodin were confirmed by GC-MS and the possible main cleavage pathways of fragment ions are discussed in this study. Rhubarb is a traditional Chinese medicinal herb which required an effective evaluation method to quantitate the four major active anthraquinone compounds described. The determinations of analytes were accomplished by GC-MS using osthole as an internal standard...
December 1, 2017: Journal of Chromatographic Science
Manman Wang, Lijuan Wang, Jinghan Sun, Lili Zhang, Longshan Zhao, Zhili Xiong
A specific, rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for simultaneous determination of vinpocetine (VP) and its active metabolite, apovincaminic acid (AVA) in rat brain regions, such as hypothalamus, striatum, cortex, cerebellum and hippocampus. Phenacetin was used as internal standard (IS). Brain tissue samples were precipitated protein by using 500 μL methanol. The separation was achieved on a Waters ACQUITY UPLC BEH C18 column (100 mm × 2...
December 1, 2017: Journal of Chromatographic Science
Yongqiang Liu, Yajie Ma, Hong Yu, Ying An
This article describes a pioneering ion-pair chromatography with indirect ultraviolet detection with imidazolium ionic liquids (ILs) as ultraviolet absorption reagent and eluting agent for determination of pyrrolidinium cations. Three pyrrolidinium cations were analyzed on a reversed-phase silica-based monolithic column by isocratic elution with imidazolium ILs-ion-pair reagents-methanol mixtures. The effects of the ultraviolet absorption reagents, detection wavelength, ion-pair reagents, imidazolium ILs, organic solvents, column temperature and flow rate on the separation and determination of pyrrolidinium cations were investigated...
December 1, 2017: Journal of Chromatographic Science
Alen N Baeza-Fonte, Idenia Garcés-Lobo, Markel D Luaces-Alberto, Luís Moreira Gonçalves, Maria D P T Sotomayor, Arístides C Valdés-González
Molecularly imprinted polymers (MIPs) were synthesized for the determination of cephalosporins (cephazolin, ceftazidime, cefotaxime, ceftriaxone, cefepime and cephalexin) by ultra-high performance liquid chromatography with diode-array detection (UHPLC-DAD). After optimization, MIPs were synthesized using cephazolin as the template, methacrylic acid as the functional monomer, triethylenglycol dimethacrylate as the crosslinker, acetonitrile/dimethylsulfoxide as porogens and benzoyl peroxide as the radical initiator...
November 28, 2017: Journal of Chromatographic Science
Qing-He Zhang, Xi-Zhen Li, Liu Han, Ping-Ya Li, Dan Lu
A ultra-performance liquid chromatography tandem mass spectrometry method was initially developed and validated for quantification of sophorabioside in rat plasma using kaempferol-3-O-β-D-rutinoside as the internal standard (IS). Analyte and IS were preparation through a protein precipitation procedure with 1.0 mL of methanol to a 0.1 mL plasma sample. The processed samples were separated by C18 analytical column using methanol/water containing 0.1% formic acid with gradient elution as the mobile phase at a flow rate of 0...
November 28, 2017: Journal of Chromatographic Science
Hassan Y Aboul-Enein, Mohamed N Aboul-Enein, Aida A El-Azzouny, Ola A Saleh, Rasha M Hassan, Kamilia M Amin
Enantioseparation of substituted 1,3-diazaspiro[4.5]decan-4-ones (1-14) was achieved using different polysaccharide type chiral stationary phases (CSPs), namely, Chiralcel OJ, Chiralcel OD and Lux-Amylose-2 using different mobile phases which were either n-hexane/2-propanol or n-hexane/ethanol mixtures of various ratios (v/v) at flow rate 1 mL min-1. UV detection was carried out at 254 nm and temperature of 20°C. The retention behavior and selectivity of these CSPs were examined in isocratic normal phase high-performance liquid chromatography mode...
November 28, 2017: Journal of Chromatographic Science
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