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The target of this study is the adaptation of the ferrozine method to flow injection analysis (FIA) to perform iron analysis in situ using an in situ chemical analyser in hydrothermal environments. The adaptation of the method to FIA was followed by its optimisation using an experimental design screening method. The goals of the optimisation steps were to decrease the detection limit and to increase...
An experimental design method was applied to determine the optimum working conditions for sequential injection analysis (SIA) to obtain second-order data that will be treated using multivariate curve resolution with alternating least squares (MCR-ALS).The critical step is to design an analytical sequence that provides relevant information. This sequence depends on parameters related to the system,...
A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug eprosartan from human plasma samples. MultiSimplex program was used to optimize the HPLC-UV method due to the number of experimental and response variables to be studied. The measured responses were the corrected area, the separation of eprosartan chromatographic peak from plasma interferences...
Two digestion procedures have been tested on nut samples for application in the determination of essential (Cr, Cu, Fe, Mg, Mn, Zn) and non-essential (Al, Ba, Cd, Pb) elements by inductively coupled plasma-optical emission spectrometry (ICP-OES). These included wet digestions with HNO 3 /H 2 SO 4 and HNO 3 /H 2 SO 4 /H 2 O 2 . The later...
A rapid and sensitive RP–HPLC method with UV detection (260nm) for routine analysis of voriconazole in a pharmaceutical formulation (Vfend ® ) was developed. Chromatography was performed with mobile phase containing a mixture of acetonitrile and water (50:50, v/v) with flow rate was of 1.0mlmin −1 . Quantitation was accomplished with internal standard method. The procedure was validated...
Capillary electrophoresis (CE) with UV photo-diode array detection technique was utilized to adopt new method for the analysis of norfloxacin and tinidazole in pharmaceuticals. Many CE aspects including separation, rapidity, sensitivity, ruggedness as well as the repeatability of qualitative and quantitative analyses were considered simultaneously for the purpose of optimization. Experimental design...
A rapid and simple method based on capillary electrophoresis was developed for the quality control of nutraceuticals containing resveratrol. Setting the UV detector at 280nm, the optimisation involved the separation of 11 effervescent tablet components, including the active compounds vitamin C, vitamin B 2 , flavanones and hydroxycinnamic acids. Flufenamic acid was employed as internal standard...
In this work, a fluorimetric approach for the determination of cyclofenil, 4-4′-(cyclohexylidenemethylene)bis(phenylacetate), is presented. The method was based on the intense fluorescence (250/410nm) observed after a UV photochemical treatment of cyclofenil. The influence of the pH and solvent system and UV exposure time on the fluorescence magnitude was studied. Optimization of parameters was made...
3-Monochloropropane-1,2-diol (3-MCPD) is the most common chemical contaminant of the group of chloropropanols. It can occur in foods and food ingredients at low levels as a result of processing, migration from packaging materials during storage and domestic cooking.A sensitive method for determination of 3-MCPD in foodstuffs using programmable temperature vaporization (PTV) with large-volume injection...
A capillary zone electrophoresis (CZE) method for the determination of chloramphenicol (CLP), danofloxacin (DANO), ciprofloxacin (CIPRO), enrofloxacin (ENRO), sulfamethazine (SMZ), sulfaquinoxaline (SQX) and sulfamethoxazole (SMX) is described. For the development, the effective mobilities were estimated and a central composite design was performed. The method was in-house validated for CLP, CIPRO,...
We used experimental design methodologies to obtain the response surface of the adsorption process for three acid dyes used in the dyeing step of a tanning process. The dyes were Acid Red 97, Acid Orange 61 and Acid Brown 425. The adsorption process was evaluated determining the concentrations of individual and total dyes remaining in solution at the end of the process. These concentrations were determined...
The determination of the optimum parameters for hydroxyl radicals (OH) formation by a TiO 2 solution has been investigated by measuring the emitted fluorescence after the reaction with terephthalic acid has occurred. After UV irradiation, the terephthalic acid was transformed into 2-hydroxyterephthalic acid whose fluorescence is directly proportional to the generated OH. Optimization of hydroxyl...
Artificial neural networks (ANN) are biologically inspired computer programs designed to simulate the way in which the human brain processes the information. In the past few years, coupling of experimental design (ED) and ANN became useful tool in the method optimization. This paper presents the application of ED–ANN in analysis of chromatographic behavior of indinavir and its degradation products...
An automated, confirmatory and sensitive procedure has been developed and validated for the determination of Sudan (I–IV), Sudan Orange G, Sudan Red 7B and Para Red in hot chilli food samples. The proposed method includes pressurised liquid extraction (PLE) with acetone, gel permeation chromatography (GPC) clean-up and detection by liquid chromatography (LC) coupled to electrospray ionization in positive...
The influence of several factors in the simultaneous photocatalytic degradation of three textile dyes – Acid Red 97, Acid Orange 61 and Acid Brown 425 – has been studied using a fractional factorial design 2 5-1 . The considered factors were: the initial concentration of each dye, the catalyst concentration (TiO 2 ) and pH.First, we developed a rapid analytical methodology based on...
An HPLC method for the separation of seven cephalosporins [Cefepime (CEP), ceftazidime (CTA), ceftizaxime (CTI), ceftriaxone (CTR), cefotaxime (COT), cefixime (CIX) and cefoperazone (COP)] in human plasma and amniotic fluid has been developed. Optimization of the chromatographic method was performed in three steps: a series of initial experiments followed by two sets of experiments based on different...
A chemometric approach was developed to optimize the grafting of a bovine milk allergen: α-Lactalbumin (α-Lac) on colloidal functionalized magnetic core–shell nanoparticles (MCSNP). Such nanoparticles, functionalized with polyethyleneglycol and amino groups, exhibit a 30nm physical diameter and behave as a quasi-homogeneous system. The α-Lac immobilization was achieved through the covalent binding...
A methodology based on multisyringe chromatography with a monolithic column was developed to determine three sulphonated azo textile dyes: Acid Yellow 23, Acid Yellow 9 and Acid Red 97. An ion pair reagent was needed because of the low affinity between the monolithic column and the anionic dyes. The proposed analytical system is simple, versatile and low-cost and has great flexibility in manifold...
A highly sensitive voltammetric method was developed for the determination of nickel in seawater at nanomolar concentrations. The measurement is based on the differential pulse cathodic adsorptive stripping of Ni(II) complexed with pyridoxal salicyloylhydrazone at a hanging mercury drop electrode. Optimal conditions were found following a two-step study strategy based on a Plackett Burman design and...
In this study, dispersive liquid–liquid microextraction (DLLME) combined with inductively coupled plasma optical emission spectrometry (ICP-OES) was developed for simultaneous preconcentration and trace determination of chromium, copper, nickel and zinc in water samples. Sodium diethyldithiocarbamate (Na-DDTC), carbon tetrachloride and methanol were used as chelating agent, extraction solvent and...
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