美国分析化学(英文)最新文献_第10页

Quantification Detection of Probiotic Bacteria Based on Plasmonic Gold-Nanoparticle Sensors 基于等离子体金纳米粒子传感器的益生菌定量检测

美国分析化学(英文) Pub Date : 2020-05-21 DOI: 10.4236/ajac.2020.115017

Fangqi Di

{"title":"Quantification Detection of Probiotic Bacteria Based on Plasmonic Gold-Nanoparticle Sensors","authors":"Fangqi Di","doi":"10.4236/ajac.2020.115017","DOIUrl":"https://doi.org/10.4236/ajac.2020.115017","url":null,"abstract":"Probiotic products are of significant research interest in recent years due to their powerful health benefits. One of the most popular commercial probiotic products is probiotic milk drinks containing Lactobacillus bacteria. The quality and effectiveness of such drinks are highly dependent on their bacterial content. However, such information is only available in producers’ advertisements—which may be misleading, and there are few studies done on the true bacterial content of these drinks. More significantly, conventional methods of measuring Lactobacillus bacterial content are laborious and time-consuming. Hence, this research aims to develop a fast and easy test that shows visible results rapidly and can be applied to other Lactobacillus-containing products. Recent developments have presented gold nanoparticles as a strong candidate for various applications in chemistry, physics, and biology for their unique optical properties. One essential optical property of gold nanoparticles is their red or blue color due to plasmon resonance. In this research, strong potential for this property of gold nanoparticles is recognised in a novel method of measuring the bacterial CFU in probiotic milk drinks. Gold nanoparticles function as the key material and indicator in this method as they are found capable of adhering to the Lactobacillus bacteria. The bacterial CFU can then be determined from the amount of gold nanoparticles attached to the bacteria. The eventual measuring scheme established enables fast (15 - 16 times faster than colony counting) and convenient (a sterile environment is not necessary) tests of the bacterial CFU in different probiotic milk drinks and has great potential in other related applications.","PeriodicalId":63216,"journal":{"name":"美国分析化学(英文)","volume":"11 1","pages":"213-220"},"PeriodicalIF":0.0,"publicationDate":"2020-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48346765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Preparation of a New Solid-State Molybdenum-Selective Electrode and Application 一种新型固态钼选择电极的制备及其应用

美国分析化学(英文) Pub Date : 2020-04-26 DOI: 10.4236/ajac.2020.115018

Ş uuml, kr uuml, Kalayci

引用次数: 1

Determination of Vitamin B12 Using Differential Pulse Polarography 用差分脉冲极谱法测定维生素B12

美国分析化学(英文) Pub Date : 2020-04-26 DOI: 10.4236/ajac.2020.115014

S. Uuml, kr uuml, Kalayci, Uuml, L. Uuml, nal, G. uuml, ler Somer

{"title":"Determination of Vitamin B12 Using Differential Pulse Polarography","authors":"S. Uuml, kr uuml, Kalayci, Uuml, L. Uuml, nal, G. uuml, ler Somer","doi":"10.4236/ajac.2020.115014","DOIUrl":"https://doi.org/10.4236/ajac.2020.115014","url":null,"abstract":"Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.","PeriodicalId":63216,"journal":{"name":"美国分析化学(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47974847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Preparation of New Uric Acid Sensors Based on Iodide Selective Electrode 基于碘化物选择电极的新型尿酸传感器的制备

美国分析化学(英文) Pub Date : 2020-04-26 DOI: 10.4236/ajac.2020.115016

Şükrü Kalayci

引用次数: 1

Synthesis and Characterization of Nano-Acetamiprid—New Plant Safeguard Nanomaterial 新型植物防护纳米材料纳米乙酰胺的合成与表征

美国分析化学(英文) Pub Date : 2020-04-26 DOI: 10.4236/ajac.2020.115015

P. Padmavathi, N. Vasundhara, Swathi Kovvuri, N. Venugopal

{"title":"Synthesis and Characterization of Nano-Acetamiprid—New Plant Safeguard Nanomaterial","authors":"P. Padmavathi, N. Vasundhara, Swathi Kovvuri, N. Venugopal","doi":"10.4236/ajac.2020.115015","DOIUrl":"https://doi.org/10.4236/ajac.2020.115015","url":null,"abstract":"In present days many types of materials are used to reduce the environmental pollution in the world which includes nanomaterials. Nanopesticides increase the efficacy, durability and reduction in the amount of active constituent. The potential applications of nanotechnology in pesticides are quick decomposition in soil or plant, targeted delivery, apparent solubility and controlled release. In this communication the author reported a neonicatonoid insecticide called as Nano-acetamiprid and it is widely used to control fungal infections in different crops like cotton, leafy vegetables, citrus fruits, pome etc. The author reported a facile method i.e. a new Nano-acetamiprid for plant disease control and its subsequent characterization of encapsulated complex using polycaprolactone as an encapsulated agent. Nano-acetamiprid encapsulated particles were characterized by dynamic light scattering (DLS), ultraviolet spectroscopy and scanning electron microscopy (SEM). To ascertain the formation and the stability of nanoencapsulated acetamiprid pesticide, the maximum absorption spectra formulated at 421 nm and unformulated pesticide at 520 nm were observed. The size distribution was noted at 40 - 50 nm. The bioactivity study was conducted against various Aspergillus niger. The performance of nano particles was many fold times effective when compared to the original parental particles. The bio-assay of Nano-acetamiprid shows better results when compared to the normal commercial acetamiprid.","PeriodicalId":63216,"journal":{"name":"美国分析化学(英文)","volume":"11 1","pages":"197-204"},"PeriodicalIF":0.0,"publicationDate":"2020-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41507029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Studies on the Stability of Corticosteroids: Degradation of Clobetasol Propionate, Desonide and Hydrocortisone in Topical Formulations by HPLC and UPLC-MS/MS 皮质类固醇稳定性的研究:外用制剂中丙酸氯倍他索、地奈德和氢化可的松的HPLC和UPLC-MS/MS降解

美国分析化学(英文) Pub Date : 2020-03-31 DOI: 10.4236/ajac.2020.114012

Kishore Kumar Hotha, Subathra Ramamoorthy, Hiren Patel

{"title":"Studies on the Stability of Corticosteroids: Degradation of Clobetasol Propionate, Desonide and Hydrocortisone in Topical Formulations by HPLC and UPLC-MS/MS","authors":"Kishore Kumar Hotha, Subathra Ramamoorthy, Hiren Patel","doi":"10.4236/ajac.2020.114012","DOIUrl":"https://doi.org/10.4236/ajac.2020.114012","url":null,"abstract":"Corticosteroids are the most widely used class of anti-inflammatory medications in the pharmaceutical industry. There are several pharmaceutical dosage forms available using different corticosteroids. Topical steroids of varying potencies are available in creams, ointments, solutions and other vehicles. Chemical instability and drug degradation are the key quality concerns for these topical dosage forms. Nature of the dosage forms, excipient quality, product composition, and process optimization are some of the common factors which affect the stability of corticosteroids. This article describes drug degradation behavior of three different corticosteroids in different topical dosage forms. Drug degradation patterns of Hydrocortisone, Clobetasol propionate and Desonide formulations observed in stability studies of respective finished drug products under ICH recommended storage conditions were investigated. HPLC, UPLC-MS/MS methods were developed for the separation and characterization of impurities. The structural elucidation of the unknown impurities observed for these steroids and mechanistic consideration of potential degradation pathways has been discussed. Detailed discussion on the analytical methodologies is included as well.","PeriodicalId":63216,"journal":{"name":"美国分析化学(英文)","volume":"11 1","pages":"147-171"},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44644247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Analytical Solution of the Non-Linear Equation in Biodegradation of N-Butanol in a Biofilter 正丁醇在生物过滤器中生物降解非线性方程的解析解

美国分析化学(英文) Pub Date : 2020-03-31 DOI: 10.4236/ajac.2020.114013

K. Saranya, V. Mohan, L. Rajendran

引用次数: 4

Trace Metals in Mussels Mytilus galloprovincialis from Dakar Coast (Senegal) 达喀尔海岸(塞内加尔)贻贝的微量金属含量

美国分析化学(英文) Pub Date : 2020-03-02 DOI: 10.4236/ajac.2020.113011

B. Ndiaye, M. Ndiaye, B. Cid, A. Diop, I. Diagne, Dame Cissé, C. Dione, Maoudo Hanne

引用次数: 10

Study of the Dispersive Component of the Surface Energy of Polylactides by Inverse Gas Chromatography at Infinite Dilution 无限稀释条件下反相气相色谱法研究聚乳酸表面能的色散成分

美国分析化学(英文) Pub Date : 2020-03-02 DOI: 10.4236/ajac.2020.113010

Carla Zarazir, M. Rajab, H. Obeid, J. Toufaily, I. Toufeili, T. Hamieh

{"title":"Study of the Dispersive Component of the Surface Energy of Polylactides by Inverse Gas Chromatography at Infinite Dilution","authors":"Carla Zarazir, M. Rajab, H. Obeid, J. Toufaily, I. Toufeili, T. Hamieh","doi":"10.4236/ajac.2020.113010","DOIUrl":"https://doi.org/10.4236/ajac.2020.113010","url":null,"abstract":"Inverse gas chromatography at infinite dilution is a powerful technique that can be advantageously used to characterize the surface physicochemical properties of solid substrates as oxides and polymers in both forms of powder or fibres. In the case of polymer, this technique can be used to determine the second order transition phenomena temperatures. This paper was devoted to the determination of the glass transition temperature of polylactide polymer. The dispersive component of the surface energy of polylactides was determined by inverse gas chromatography at infinite dilution. Various theoretical models were used to deduce the dispersive component of the surface energy of the solid substrates. These models are based on the calculation of the molecular areas of adsorbed molecules on the polymer surface: geometrical model, cylindrical molecular model, liquid density model, BET method, Kiselev results and the two-dimensional Van der Waals and Redlich-Kwong equations. The curves relative to the variation of as a function of the temperature showed a specific graph with a maximum value of at a certain particular temperature characteristic to the investigated polylactide polymer. In fact, the maxima of indicated the presence of glass transition temperature Tg of polylactide whatever the molecular model used. This study showed a glass transition temperature equal to 64°C confirming that obtained by other studies.","PeriodicalId":63216,"journal":{"name":"美国分析化学(英文)","volume":"11 1","pages":"129-136"},"PeriodicalIF":0.0,"publicationDate":"2020-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42454714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Electrochemical Biosensor for Multiple Methylation-Locus Analysis Based on DNA-AuNPs and Bienzymatic Dual Signal Amplifications 基于DNA AuNPs和双酶双信号放大的电化学多甲基化位点分析传感器

美国分析化学(英文) Pub Date : 2020-02-03 DOI: 10.4236/ajac.2020.112005

Shasha Su, Shu Zhang, Jiang-hong Huang, Xi Chen, Yan Li, Lichao Fang, Jun Deng, F. Mo, Junsong Zheng

{"title":"Electrochemical Biosensor for Multiple Methylation-Locus Analysis Based on DNA-AuNPs and Bienzymatic Dual Signal Amplifications","authors":"Shasha Su, Shu Zhang, Jiang-hong Huang, Xi Chen, Yan Li, Lichao Fang, Jun Deng, F. Mo, Junsong Zheng","doi":"10.4236/ajac.2020.112005","DOIUrl":"https://doi.org/10.4236/ajac.2020.112005","url":null,"abstract":"DNA methylation plays a significant role in various biological events, and its precise determination is vital for the prognosis and treatment of cancer. Here, we proposed an ultrasensitive electrochemical biosensor for the quantitative analysis of multiple methylation-locus in DNA sequence via DNA anchoring the gold nanoparticles (DNA-AuNPs) and bienzyme dual signal amplifications. After the target DNA captured by the DNA-AuNPs of the biosensor, the methyl-CpG binding protein MeCP2 could specifically conjugate to the methylation-loci in the double-stranded DNA. Successively, the glucose oxidase (GOD) and horseradish (HRP) co-labeled antibody captured the His tagged MeCP2, which leads to a cascade enzymatic catalysis of the substrates to yield a detectable electrochemical signal. Both the two strategies, including the high content of DNA-AuNPs and the associated catalysis of bienzyme, dramatically enhanced the sensitivity of the biosensor. The response current elevated with the increasing numbers of methylation-locus, thus the multiple methylated DNA was identified by detecting the corresponding current signals. This method could detect the methylated target as low as 0.1 fM, and showed a wide linear range from 10 - 15 M to 10 - 7 M. Besides, the long-term stability and repeatability of the biosensor were also validated. The prepared electrochemical immunosensor exhibits ultrasensitivity through the bienzyme labeling process, which can be applied for the detection of DNA methylation with low concentration.","PeriodicalId":63216,"journal":{"name":"美国分析化学(英文)","volume":"11 1","pages":"61-74"},"PeriodicalIF":0.0,"publicationDate":"2020-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44868214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0