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Analytical Chemistry Insights

Khaled M Mohamed, Abdulsallam Bakdash
The heptafluorobutyric anhydride (HFBA), pentafluoropropionic anhydride (PFPA), and trifluoroacetic anhydride (TFAA) are compared as derivatizing reagents to use as the optimal method for the analysis of 10 amphetamines and cathinones in oral fluid. The target compounds were amphetamine (AMP), methamphetamine (MA), 4-methylamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), cathinone (CAT), methcathinone, mephedrone, and ephedrine...
2017: Analytical Chemistry Insights
Ask Sankar, Shanmugasundaram Palani, Ravichandiran Velayudham
This research article presents the Quality by Design (QbD)-finalised conditions for a method that uses liquid chromatography-tandem mass spectrometry for the determination of concentration of enzalutamide (ENZ), an atypical anticancer drug, in a drug formulation and in spiked plasma samples. Critical process attributes (CPA) considered to be the influential parameters in separation, identification, and quantification processes by ultrahigh-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UHPLC-ESI-MS/MS) were organic content, buffer strength, pH modifier, flow rate, spray voltage, sheath gas, and auxiliary gas that alter critical analytical attributes, such as retention time (R1) and area (R2)...
2017: Analytical Chemistry Insights
Tyler L Dost, Michael T Gressel, Maged Henary
Cyanine dyes possessing carboxylic acid groups have been used in many different fields of study. The acid groups can act as handles for bioconjugation or as metal chelators. Several pentamethine cyanine dyes with propionic acid handles were synthesized and their optical properties were studied to determine their usefulness as fluorescent probes. The optical properties studies performed include the absorbance and emission maxima values as well as the calculation of quantum yield and molecular brightness levels...
2017: Analytical Chemistry Insights
Nidal Batrawi, Shorouq Wahdan, Murad Abualhasan
Medroxyprogesterone acetate is widely used in veterinary medicine as intravaginal dosage for the synchronization of breeding cycle in ewes and goats. The main goal of this study was to develop reverse-phase high-performance liquid chromatography method for the quantification of medroxyprogesterone acetate in veterinary vaginal sponges. A single high-performance liquid chromatography/UV isocratic run was used for the analytical assay of the active ingredient medroxyprogesterone. The chromatographic system consisted of a reverse-phase C18 column as the stationary phase and a mixture of 60% acetonitrile and 40% potassium dihydrogen phosphate buffer as the mobile phase; the pH was adjusted to 5...
2017: Analytical Chemistry Insights
Joseph de Nanassy, Dina El Demellawy
Immunohistochemical (IHC) stains are widely used by pathologists for a variety of considerations in the diagnostic workup of pediatric nonneoplastic lesions in gastrointestinal (GI), hepatic, biliary, and pancreatic lesions. The pathologic changes cover a wide range and types of presentations, including inflammatory (bacterial and viral), metaplastic, posttransplant lymphoproliferative, autoimmune, metabolic, degenerative, developmental, and genetic conditions, among others. The everyday practical value of IHC stains covers primary identification, confirmation, differential, and/or exclusionary roles in the hands and eyes and minds of the practitioners...
2017: Analytical Chemistry Insights
Eman Alzahrani
The use of nanoparticles in sensing is attracting the interest of many researchers. The aim of this work was to fabricate Acacia gum-stabilised silver nanoparticles (SNPs) using green chemistry to use them as a highly sensitive and cost-effective localised surface plasmon resonance (LSPR) colorimeter sensor for the determination of reactive oxygen species, such as hydrogen peroxide (H2O2). Silver nanoparticles were fabricated by the reduction of an inorganic precursor silver nitrate solution (AgNO3) using white sugar as the reducing reagent and Acacia gum as the stabilising reagent and a sonication bath to form uniform silver nanoparticles...
2017: Analytical Chemistry Insights
Tom Manczak, Henrik Toft Simonsen
A fast and reproducible protocol was established for enzymatic characterization of plant sesquiterpene synthases that can incorporate radioactivity in their products. The method utilizes the 96-well format in conjunction with cluster tubes and enables processing of >200 samples a day. Along with reduced reagent usage, it allows further reduction in the use of radioactive isotopes and flammable organic solvents. The sesquiterpene synthases previously characterized were expressed in yeast, and the plant-derived Thapsia garganica kunzeaol synthase TgTPS2 was tested in this method...
2016: Analytical Chemistry Insights
Farhad Ghamari, Abdulrahman Bahrami, Yadollah Yamini, Farshid Ghorbani Shahna, Abbas Moghimbeigi
For the first time, hollow-fiber liquid-phase microextraction combined with high-performance liquid chromatography-ultraviolet was used to extract trans,trans-muconic acid, in urine samples of workers who had been exposed to benzene. The parameters affecting the metabolite extraction were optimized as follows: the volume of sample solution was 11 mL with pH 2, liquid membrane containing dihexyl ether as the supporter, 15% (w/v) of trioctylphosphine oxide as the carrier, the time of extraction was 120 minutes, and stirring rate was 500 rpm...
2016: Analytical Chemistry Insights
Ammar Haidar, Sofiane Kabiche, Elyes Majoul, Issa-Bella Balde, Jean-Eudes Fontan, Salvatore Cisternino, Joël Schlatter
A stability-indicating assay by reversed-phase high performance liquid chromatography method was developed and validated for the determination of sulthiame (STM). The chromatographic separation was achieved on a reversed-phase NovaPack C18 column and an isocratic mobile phase consisting of deionized water:methanol (70:30, v/v). The flow rate was 1.0 mL/min (ultraviolet detection at 210 nm). The STM was separated within 2.83 min. The linearity of the method was demonstrated in the range of 20.0-200.0 μg/mL and a coefficient of determination of r (2) = 0...
2016: Analytical Chemistry Insights
Thibaut Istasse, Nicolas Jacquet, Thomas Berchem, Eric Haubruge, Bach Kim Nguyen, Aurore Richel
Honey polyphenols have been studied with the objective of relating honeys to their floral sources. Initially synthesized by plant, these polyphenols can be found in the plant's nectar, which are collected by bees, which convert the nectar into honey. Consequently, polyphenols constitute minor components of honey. The development of a solid-phase extraction method for honey polyphenols is presented in this study. The technique employs Amberlite XAD-2 adsorbent and was tested on monofloral honeys from six different plants: acacia, chestnut, eucalyptus, thyme, sunflower, and wild carrot...
2016: Analytical Chemistry Insights
Tonu Reinot, Jinhai Chen, Adam Kell, Mahboobe Jassas, Kevin C Robben, Valter Zazubovich, Ryszard Jankowiak
We focus on problems with elucidation of site energies [Formula: see text] for photosynthetic complexes (PSCs) in order to raise some genuine concern regarding the conflicting estimations propagating in the literature. As an example, we provide a stern assessment of the site energies extracted from fits to optical spectra of the widely studied CP47 antenna complex of photosystem II from spinach, though many general comments apply to other PSCs as well. Correct values of [Formula: see text] for chlorophyll (Chl) a in CP47 are essential for understanding its excitonic structure, population dynamics, and excitation energy pathway(s)...
2016: Analytical Chemistry Insights
Temesgen Achamo, O P Yadav
Photocatalytic oxidation using semiconductor nanoparticles is an efficient, eco-friendly, and cost-effective process for the removal of organic pollutants, such as dyes, pesticides, phenols, and their derivatives in water. In the present study, nanosize Ag-N-P-tridoped titanium(IV) oxide (TiO2) was prepared by using sol-gel-synthesized Ag-doped TiO2 and soybean (Glycine max) or chickpea (Cicer arietinum) seeds as nonmetallic bioprecursors. As-synthesized photocatalysts were characterized using X-ray diffraction, Fourier transform infrared, and ultra violet (UV)-visible spectroscopic techniques...
2016: Analytical Chemistry Insights
Michael G Weller
According to several recent studies, an unexpectedly high number of landmark papers seem to be not reproducible by independent laboratories. Nontherapeutic antibodies used for research, diagnostic, food analytical, environmental, and other purposes play a significant role in this matter. Although some papers have been published offering suggestions to improve the situation, they do not seem to be comprehensive enough to cover the full complexity of this issue. In addition, no obvious improvements could be noticed in the field as yet...
2016: Analytical Chemistry Insights
Pradnya N Vaingankar, Purnima D Amin
A simple reversed-phase high-performance liquid chromatography method was developed and validated for simultaneous determination of Metformin hydrochloride (MET) and Glimepiride (GLM) in combination and estimation of their principal degradation products. The separation was achieved using JASCO Finepak SIL (250 mm × 4.6 mm i.d. 5 μm) at ambient temperature. The optimized mobile phase composed of an aqueous phase (20 mM phosphate buffer, adjusted to pH 3.0) and an organic phase (methanol:acetonitrile; 62.5:37...
2016: Analytical Chemistry Insights
Sophia Karastogianni, Stella Girousi
Investigation of the electrochemical behavior using cyclic voltammetry and detection of [Mn(2+)(thiophenyl-2-carboxylic acid)2 (triethanolamine)] with adsorptive stripping differential pulse voltammetry. The electrochemical behavior of a manganese(II) complex [Mn(2+)(thiophenyl-2-carboxylic acid)2(triethanolamine)] (A) was investigated using cyclic and differential pulse voltammetry in an acetate buffer of pH 4.6 at a carbon paste electrode. Further, an oxidation-reduction mechanism was proposed. Meanwhile, an adsorptive stripping differential pulse voltammetric method was developed for the determination of manganese(II) complex...
2016: Analytical Chemistry Insights
Niki Tsartsali, Victoria F Samanidou
A quick, easy, cheap, effective, rugged, and safe (QuEChERS) dispersive extraction method is proposed herein for the isolation and cleanup of melamine and cyromazine from chicken egg yolk. Analytes are determined by high-performance liquid chromatography using photodiode array detector after separation on a LiChroCART® (250 × 4 mm)-LiChrospher® RP-8e, 5 μm analytical column using a mobile phase of 0.1% trifluoracetic acid and methanol (80:20 v/v) delivered isocratically at a flow rate of 1 mL/minute. Extraction of isolated compounds was achieved by methanol and acetonitrile mixture (1:1 v/v)...
2015: Analytical Chemistry Insights
R P Bhole, S S Shinde, S S Chitlange, S B Wankhede
A rapid and simple high-performance thin layer chromatography (HPTLC) method with densitometry at 230 nm was developed and validated for simultaneous determination of diphenhydramine hydrochloride (DPH) and naproxen sodium (NPS) from pharmaceutical preparation. The separation was carried out on aluminum plates precoated with silica gel 60 F254 using mobile phase toluene:methanol:glacial acetic acid (7.5:1:0.2, v/v/v). The linearity range lies between 200 and 1200 ng/band for DPH and 1760 and 10,560 ng/band for NPS with correlation coefficients of 0...
2015: Analytical Chemistry Insights
Fan An, Yueyang Qu, Xianming Liu, Runtao Zhong, Yong Luo
Direct detection and analysis of biomolecules and cells in physiological microenvironment is urgently needed for fast evaluation of biology and pharmacy. The past several years have witnessed remarkable development opportunities in vitro organs and tissues models with multiple functions based on microfluidic devices, termed as "organ-on-a-chip". Briefly speaking, it is a promising technology in rebuilding physiological functions of tissues and organs, featuring mammalian cell co-culture and artificial microenvironment created by microchannel networks...
2015: Analytical Chemistry Insights
Mrudul R Keskar, Ravin M Jugade
Macrolides, one of the most commonly used class of antibiotics, are a group of drugs produced by Streptomyces species. They belong to the polyketide class of natural products. Their activity is due to the presence of a large macrolide lactone ring with deoxy sugar moieties. They are protein synthesis inhibitors and broad-spectrum antibiotics, active against both gram-positive and gram-negative bacteria. Different analytical techniques have been reported for the determination of macrolides such as chromatographic methods, flow injection methods, spectrofluorometric methods, spectrophotometric methods, and capillary electrophoresis methods...
2015: Analytical Chemistry Insights
David M Parham
After ~30 years of widespread usage, immunohistochemistry (IHC) has become a standard method of diagnosis for surgical pathology. Because of the plethora of diagnoses and often subtle nature of diagnostic criteria, IHC finds particular utility in soft tissue tumors. The use of progressively small amounts of tissue for diagnosis highlights the importance of this method. The sensitivity and crispness of IHC stains have progressively improved with the advent of new techniques. Traditionally, IHC detects cell-typic markers that characterize cell phenotypes, such as chromogranin for neuroectodermal tissue, myogenin for skeletal muscle, and cytokeratin for epithelium...
2015: Analytical Chemistry Insights
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