Analytical Chemistry Insights最新文献_第4页

Preliminary development of a fiber optic sensor for measuring bilirubin. 胆红素光纤传感器的初步研制。

Analytical Chemistry Insights Pub Date : 2014-07-01 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S14711

Steven M Babin, Raymond M Sova

引用次数: 8

Corrigendum to "Utility of Experimental Design in Pre-Column Derivatization for the Analysis of Tobramycin by HPLC-Fluorescence Detection: Application to Ophthalmic Solution and Human Plasma". “hplc -荧光检测分析妥布霉素柱前衍生化实验设计的应用:在眼科溶液和人血浆中的应用”的勘误。

Analytical Chemistry Insights Pub Date : 2014-06-11 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S16710

Asmaa A El-Zaher, Marianne A Mahrouse

{"title":"Corrigendum to \"Utility of Experimental Design in Pre-Column Derivatization for the Analysis of Tobramycin by HPLC-Fluorescence Detection: Application to Ophthalmic Solution and Human Plasma\".","authors":"Asmaa A El-Zaher, Marianne A Mahrouse","doi":"10.4137/ACI.S16710","DOIUrl":"https://doi.org/10.4137/ACI.S16710","url":null,"abstract":"A novel, selective, and sensitive reversed phase high-performance liquid chromatography (HPLC) method coupled with fluorescencedetectionhasbeendevelopedfor thedeterminationof tobramycin (TOB) inpure form, inophthalmicsolutionand in spikedhumanplasma.SinceTOBlacksUVabsorbingchromophoresandnativefluorescence,pre-columnderivatizationofTOBwas carriedoutusingfluorescaminereagent(0.01%,1.5mL)andboratebuffer(pH8.5,2mL).Experimentaldesignwasappliedforoptimizationofthederivatizationstep.Theresultinghighlyfluorescentstable derivative was chromatographed on C18 column and eluted usingmethanol:water(60:40,v/v)ataflowrateof1mLmin.Afluorescencedetector(λex390andλem480nm)wasused.Themethod waslinearovertheconcentrationrange20–200ngmL−1.Thestructureofthefluorescentproductwasproposed,themethodwasthen validatedandappliedforthedeterminationofTOBinhumanplasma.Theresultswerestatisticallycomparedwiththereferencemethod, revealingnosignificantdifference.","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"9 ","pages":"57"},"PeriodicalIF":0.0,"publicationDate":"2014-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064956/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32452208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Determination of xanthine in the presence of hypoxanthine by adsorptive stripping voltammetry at the mercury film electrode. 汞膜电极吸附溶出伏安法测定次黄嘌呤中的黄嘌呤。

Analytical Chemistry Insights Pub Date : 2014-06-09 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S14712

Percio Augusto Mardini Farias, Arnaldo Aguiar Castro

{"title":"Determination of xanthine in the presence of hypoxanthine by adsorptive stripping voltammetry at the mercury film electrode.","authors":"Percio Augusto Mardini Farias, Arnaldo Aguiar Castro","doi":"10.4137/ACI.S14712","DOIUrl":"https://doi.org/10.4137/ACI.S14712","url":null,"abstract":"A stripping method for the determination of xanthine in the presence of hypoxanthine at the submicromolar concentration levels is described. The method is based on controlled adsorptive accumulation at the thin-film mercury electrode followed by a fast linear scan voltammetric measurement of the surface species. Optimum experimental conditions were found to be the use of 1.0 × 10(-3) mol L(-1) NaOH solution as supporting electrolyte, an accumulation potential of 0.00 V for xanthine and -0.50 V for hypoxanthine-copper, and a linear scan rate of 200 mV second(-1). The response of xanthine is linear over the concentration ranges of 20-140 ppb. For an accumulation time of 30 minutes, the detection limit was found to be 36 ppt (2.3 × 10(-10) mol L(-1)). Adequate conditions for measuring the xanthine in the presence of hypoxanthine, copper and other metals, uric acid, and other nitrogenated bases were also investigated. The utility of the method is demonstrated by the presence of xanthine associated with hypoxanthine, uric acid, nitrogenated bases, ATP, and ssDNA. ","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"9 ","pages":"49-55"},"PeriodicalIF":0.0,"publicationDate":"2014-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4055419/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32434026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Kinetic Study of the Alkaline Degradation of Oseltamivir Phosphate and Valacyclovir Hydrochloride using Validated Stability Indicating HPLC. 稳定性指示高效液相色谱法研究磷酸奥司他韦和盐酸伐昔洛韦的碱性降解动力学。

Analytical Chemistry Insights Pub Date : 2014-05-27 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S13878

Ramzia I Al-Bagary, Asmaa A El-Zaher, Fahima A Morsy, Mai M Fouad

{"title":"Kinetic Study of the Alkaline Degradation of Oseltamivir Phosphate and Valacyclovir Hydrochloride using Validated Stability Indicating HPLC.","authors":"Ramzia I Al-Bagary, Asmaa A El-Zaher, Fahima A Morsy, Mai M Fouad","doi":"10.4137/ACI.S13878","DOIUrl":"https://doi.org/10.4137/ACI.S13878","url":null,"abstract":"Aqueous alkaline degradation was performed for oseltamivir phosphate (OP) and valacyclovir hydrochloride (VA). Isocratic stability indicating the use of high-performance liquid chromatography (HPLC) was presented for each drug in the presence of its degradation product. The separations were performed using the Nucleosil ODS column and a mobile phase consisting of phosphate buffer (pH = 7), acetonitrile, and methanol 50:25:25 (v/v/v) for OP. For VA separation, a Nucleosil CN column using phosphate buffer (pH = 7) and methanol 85:15 (v/v) was used as a mobile phase. Ultraviolet detection at 210 nm and 254 nm was used for OP and VA, respectively. The method showed high sensitivity concerning linearity, accuracy, and precision over the range 1-250 μg mL(-1) for both drugs. The proposed method was used to determine the drug in its pharmaceutical formulation and to investigate the degradation kinetics of each drug's alkaline-stressed samples. The reactions were found to follow a first-order reaction. The activation energy could also be estimated. International Conference on Harmonisation guidelines were adopted for method validation. ","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"9 ","pages":"41-8"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/ACI.S13878","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32425480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Spectrophotometric and spectrofluorimetric studies on azilsartan medoxomil and chlorthalidone to be utilized in their determination in pharmaceuticals. 阿齐沙坦、美多索米和氯噻酮的分光光度法和荧光光度法研究。

Analytical Chemistry Insights Pub Date : 2014-05-07 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S13768

Walid M Ebeid, Ehab F Elkady, Asmaa A El-Zaher, Ramzia I El-Bagary, Gabor Patonay

{"title":"Spectrophotometric and spectrofluorimetric studies on azilsartan medoxomil and chlorthalidone to be utilized in their determination in pharmaceuticals.","authors":"Walid M Ebeid, Ehab F Elkady, Asmaa A El-Zaher, Ramzia I El-Bagary, Gabor Patonay","doi":"10.4137/ACI.S13768","DOIUrl":"https://doi.org/10.4137/ACI.S13768","url":null,"abstract":"The recently approved angiotensin II receptor blocker, azilsartan medoxomil (AZL), was determined spectrophotometrically and spectrofluorimetrically in its combination with chlorthalidone (CLT) in their combined dosage form. The UV-spectrophotometric technique depends on simultaneous measurement of the first derivative spectra for AZL and CLT at 286 and 257 nm, respectively, in methanol. The spectrofluorimetric technique depends on measurement of the fourth derivative of the synchronous spectra intensities of AZL in presence of CLT at 298 nm in methanol. The effects of different solvents on spectrophotometric and spectrofluorimetric responses were studied. For, the spectrofluorimetric study, the effect of pH and micelle-assisted fluorescence enhancement were also studied. Linearity, accuracy, and precision were found to be satisfactory over the concentration ranges of 8-50 μg mL(-1) and 2-20 μg mL(-1) for AZL and CLT, respectively, in the spectrophotometric method as well as 0.01-0.08 μg mL(-1) for AZL in the spectrofluorimetric method. The methods were successfully applied for the determination of the studied drugs in their co-formulated tablets. The developed methods are inexpensive and simple for the quality control and routine analysis of the cited drugs in bulk and in pharmaceuticals. ","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"9 ","pages":"33-40"},"PeriodicalIF":0.0,"publicationDate":"2014-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/ACI.S13768","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32363560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25

A UPLC-MS Method for the Determination of Ofloxacin Concentrations in Aqueous Humor. 高效液相色谱-质谱法测定房水中氧氟沙星浓度。

Analytical Chemistry Insights Pub Date : 2014-05-05 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S13857

Panagiotis Plotas, Charalampos Anastasopoulos, Olga E Makri, Michalis Leotsinidis, Constantine D Georgakopoulos

引用次数: 11

Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC. 纳米纤维固相萃取法测定尿中1-羟基芘含量。

Analytical Chemistry Insights Pub Date : 2014-04-22 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S13560

Okechukwu Clinton Ifegwu, Chimezie Anyakora, Samuel Chigome, Nelson Torto

{"title":"Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC.","authors":"Okechukwu Clinton Ifegwu, Chimezie Anyakora, Samuel Chigome, Nelson Torto","doi":"10.4137/ACI.S13560","DOIUrl":"https://doi.org/10.4137/ACI.S13560","url":null,"abstract":"It is always desirable to achieve maximum sample clean-up, extraction, and pre-concentration with the minimum possible organic solvent. The miniaturization of sample preparation devices was successfully demonstrated by packing 10 mg of 11 electrospun polymer nanofibers into pipette tip micro column and mini disc cartridges for efficient pre-concentration of 1-hydroxypyrene in urine samples. 1-hydroxypyrene is an extensively studied biomarker of the largest class of chemical carcinogens. Excretory 1-hydroxypyrene was monitored with HPLC/fluorescence detector. Important parameters influencing the percentage recovery such as fiber diameter, fiber packing amount, eluent, fiber packing format, eluent volume, surface area, porosity, and breakthrough parameters were thoroughly studied and optimized. Under optimized condition, there was a near perfect linearity of response in the range of 1-1000 μg/L with a coefficient of determination (r (2)) between 0.9992 and 0.9999 and precision (% RSD) ≤7.64% (n = 6) for all the analysis (10, 25, and 50 μg/L). The Limit of detection (LOD) was between 0.022 and 0.15 μg/L. When compared to the batch studies, both disc packed nanofiber sorbents and pipette tip packed sorbents exhibited evident dominance based on their efficiencies. The experimental results showed comparable absolute recoveries for the mini disc packed fibers (84% for Nylon 6) and micro columns (80% for Nylon 6), although the disc displayed slightly higher recoveries possibly due to the exposure of the analyte to a larger reacting surface. The results also showed highly comparative extraction efficiencies between the nanofibers and conventional C-18 SPE sorbent. Nevertheless, miniaturized SPE devices simplified sample preparation, reducing back pressure, time of the analysis with acceptable reliability, selectivity, detection levels, and environmental friendliness, hence promoting green chemistry. ","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"9 ","pages":"17-25"},"PeriodicalIF":0.0,"publicationDate":"2014-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999818/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32327576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 18

Buprenorphine and norbuprenorphine determination in mice plasma and brain by gas chromatography-mass spectrometry. 气相色谱-质谱法测定小鼠血浆和脑组织中丁丙诺啡和去甲丁丙诺啡。

Analytical Chemistry Insights Pub Date : 2014-03-10 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S13515

Fouad Chiadmi, Joël Schlatter

引用次数: 18

Synthesis and Characterization of Maillard Reaction Products of Salbutamol and Terbutaline with Lactose and Development and Validation of an LC Method for the Determination of Salbutamol and Terbutaline in the Presence of These Impurities. Salbutamol和Terbutaline与乳糖的美拉德反应产物的合成与表征以及在杂质存在下测定Salbutamol和Terbutaline的LC法的建立与验证。

Analytical Chemistry Insights Pub Date : 2014-03-02 eCollection Date: 2014-01-01 DOI: 10.4137/ACI.S13835

Asmaa A El-Zaher, Marwa A Fouad, Ehab F Elkady

{"title":"Synthesis and Characterization of Maillard Reaction Products of Salbutamol and Terbutaline with Lactose and Development and Validation of an LC Method for the Determination of Salbutamol and Terbutaline in the Presence of These Impurities.","authors":"Asmaa A El-Zaher, Marwa A Fouad, Ehab F Elkady","doi":"10.4137/ACI.S13835","DOIUrl":"https://doi.org/10.4137/ACI.S13835","url":null,"abstract":"Being secondary amines, both salbutamol (SLB) and terbutaline (TRB) react by Maillard reaction (MR) with lactose, which is added as an inactive ingredient in tablets. The Amadori rearrangement products were synthesized, isolated, and characterized by mass spectrometry. In addition, a simple, selective, and precise reversed-phase liquid chromatography (LC) method was developed and validated for the determination of SLB and TRB in tablets, each in the presence of its MR impurity. The chromatographic separation was performed on a Symmetry(®) Waters C18 column (150 mm × 4.6 mm, 5 μm) using a mobile phase consisting of 0.5% aqueous phosphoric acid to acetonitrile (90:10, v/v) at a flow rate of 0.7 mL minute(-1). Quantitation was achieved using UV detection at 230 nm. Linearity, accuracy, and precision were found to be acceptable for the determination of SLB and TRB in the concentration range of 0.2-60 and 0.5-80 μg mL(-1), respectively. The proposed method was successfully applied to the determination of SLB and TRB in bulk and in their tablets. ","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"9 ","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2014-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/ACI.S13835","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32181750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Simultaneous determination of amlodipine besylate and atorvastatin calcium in binary mixture by spectrofluorimetry and HPLC coupled with fluorescence detection. 荧光光谱法和高效液相色谱法同时测定苯磺酸氨氯地平和阿托伐他汀钙的含量。

Analytical Chemistry Insights Pub Date : 2013-11-04 eCollection Date: 2013-01-01 DOI: 10.4137/ACI.S12921

Bahia A Moussa, Asmaa A El-Zaher, Marianne A Mahrouse, Maha S Ahmed

{"title":"Simultaneous determination of amlodipine besylate and atorvastatin calcium in binary mixture by spectrofluorimetry and HPLC coupled with fluorescence detection.","authors":"Bahia A Moussa, Asmaa A El-Zaher, Marianne A Mahrouse, Maha S Ahmed","doi":"10.4137/ACI.S12921","DOIUrl":"https://doi.org/10.4137/ACI.S12921","url":null,"abstract":"Caduet tablets are novel prescription drug that combines amlodipine besylate (AM) with atorvastatin calcium (AT). A spectrofluorimetric and an HPLC-fluorescence detection methods were developed for simultaneous determination of both drugs in tablets. In the spectrofluorimetric method, native fluorescence of AM and AT were measured in methanol at 442 and 369 nm upon excitation at 361 and 274 nm, respectively. The emission spectrum of each drug reveals zero value at the emission wavelength of the other drug, thus allowing their simultaneous determination without interference. In the HPLC method, separation of AM and AT was achieved within 8 minutes on a C18 column using acetonitrile:phosphate buffer (0.015 M, pH 3) (45:55, v/v) as the mobile phase. Fluorescence detection was carried out using excitation wavelengths 361 and 274 nm and emission wavelengths 442 and 378 nm for AM and AT, respectively. Excellent linearity was observed. Careful validation proved advantages of the new methods: high sensitivity, accuracy, selectivity and suitability for quality control laboratories. ","PeriodicalId":7781,"journal":{"name":"Analytical Chemistry Insights","volume":"8 ","pages":"107-15"},"PeriodicalIF":0.0,"publicationDate":"2013-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/ACI.S12921","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31880741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 29