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The determination of psilocybin was carried out by reversed-phase liquid chromatography (HPLC) with fluorescence (FL) detection. Psilocybin was labeled with 5-dimethylaminonaphthalene-1-[N-(2-aminoethyl)]sulfonamide (DNS-ED) at 60°C for 4h in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) as the activation reagent. The resulting derivative was separated on a Mightysil RP-18 GP...
A continuous ultrasound-assisted extraction system connected to a flow injection manifold has been used for the on-line determination of zinc in meat samples by flame atomic absorption spectrometry. An experimental design was used for the optimisation of the continuous manifold. This flow injection methodology allowed a sampling frequency of ca. 80 samples per hour with a relative standard deviation...
To improve the selectivity of surfactant sensors, the surface of their membranes was modified with molecular sieves with predetermined pore sizes. Water-soluble anionic, cationic and non-ionic surfactants were used as pore generators in the molecular sieves and introduced into the source membrane at the stage of its formation. The modified sensors enable detection of alkylsulfates homologues and alkylpyridinium...
Liquid–liquid–liquid phase microextraction (LLLME) coupled with high-performance liquid chromatography (HPLC) for the analysis of some aromatic amines is described. These compounds were extracted from 4.0mL aqueous sample that adjusted to pH 13 with, NaOH–NaCl buffer solution (donor phase, P 1 ) into an organic phase (P 2 ) 150μl benzyl alcohol and ethyl acetate (2:1) and then back...
Menthol (MT) induces strong room temperature phosphorescence (RTP) of 1-bromonaphthalene (1BrN) in aqueous β-cyclodextrin (β-CD) suspensions, even under non-deoxygenated conditions. Interestingly, (−)-MT and (+)-MT enantiomers give rise to different phosphorescence intensities, the difference being 19±3%. It is argued that the signal can be mainly ascribed to the formation of ternary complexes β-CD/1BrN/MT...
The electrophoretic behavior of γ-Fe 2 O 3 nanoparticles was studied in aqueous solutions of Na 2 SO 4 –NaOH (pH 10.8) and of Na 2 SO 4 –Na 3 cit (pH 7.1) as running electrolytes. Two electrophoretic zones (smooth and with spikes) due to colloidal and suspended particles of approximately the same size range were formed during the runs. The suspension...
Methods were developed for indium (In) determination in complex ores by electrothermal atomization atomic absorption spectrometry using matrix modification after its separation with Amberlite XAD-2 coated with 1-(2-pyridylazo)-2-naphthol (PAN). Palladium–magnesium, nickel, and zinc nitrates were used as matrix modifiers and were compared in terms of maximum pyrolysis temperature, sensitivity and background...
In the last decade, significant advances in flow analysis have been reported, namely the extensive use of computer-controlled devices to enhance the autonomy and performance of analysers. In the present work, computer-controlled multi-syringe flow injection systems are proposed to perform the spectrophotometric determination of available iron and boron in soil extracts. The methodologies were based...
A multiwavelength spectrophotometric titration method was applied to study the protolytic constants of 4-(2-pyridylazo) resorcinol(PAR), in binary DMF+water mixtures. UV–vis absorption spectra of PAR solution were recorded in the course of pH-metric titration of acidic solutions of PAR with standard base solution. The protolytic equilibrium constants, spectral profiles, concentration diagrams and...
A new simple, selective and sensitive method for the determination of trace chlorine dioxide in water has been developed, based on the oxidation by chlorine dioxide to reduction the fluorescence of rhodamine dyes in ammonia–ammonium chloride buffer solution. Four rhodamine dyes systems such as rhodamine S, rhodamine G, rhodamine B and butyl-rhodamine B were tested. The rhodamine S system is the best,...
A soluble Mn (IV)-formaldehyde-indomethacin chemiluminescence system was found. Using a synthesized indomethacin MIP as recognition material and soluble Mn (IV)-formaldehyde-indomethacin as detection system, a new molecule imprinted-chemiluminesence method of determination of indomethacin was established. The response range of this method was between 1.0×10 −7 and 1.0×10 −5 g/mL with...
In this paper a new and very simple method was developed for the simultaneous determination of binary and ternary mixtures, without prior separation steps. This method is based on the mean centering of ratio spectra. The mathematical explanation of the procedure is illustrated. After modeling procedure, the method has been successfully applied to the simultaneous analysis of binary mixtures of mefnamic...
A critical comparison of the various PCA methods on the absorbance matrix data concerning the complexation equilibria between SNAZOXS and Cd 2+ , Co 2+ , Cu 2+ , Ni 2+ , Pb 2+ and Zn 2+ or Naphtylazoxine 6S and Cd 2+ , Cu 2+ , Ni 2+ and Zn 2+ at 25°C is performed. The number of complex species in a complex-forming equilibria...
High-performance liquid chromatography with photo-assisted electrochemical detection (HPLC–PAED) is used in conjunction with ultraviolet absorbance (UV) detection for determining explosives in environmental samples. The system utilizes an on-line solid-phase extraction technique for sample pretreatment (i.e., fractionation and concentration), thus reducing the required ground water sample size from...
A novel analytical technique has been suggested for determination of Pb using formation of PbH 4 (g) by chemical reduction and its subsequent spectrophotometric measurement in IR region, using the peak at 1821.4cm −1 . The range of measurements is 1.0–30.0mgl −1 using a sample of 1.0ml in flow injection mode. The 3σ limit of detection is 0.28mgl −1 . The method has...
An ultrasound-assisted solvent extraction procedure has been optimised to speed up total polycyclic aromatic hydrocarbons (T-PAHs) extraction from mussel soft tissue. The T-PAHs releases have been evaluated by spectrofluorimetry (excitation and fluorescence emission wavelengths of 300 and 382nm, respectively, and using chrysene as calibrant). Variables such as sonication time, ultrasound frequency,...
A sensitive and selective phosphorimetric method for the determination of 1-naphthaleneacetic acid (1-NAA) based on a flow-injection system connected to a flow cell packed with a solid support and placed in the sample compartment of a conventional luminescence spectrometer is described. A non-ionic solid polymeric resin Amberlite XAD-7 is used for the packing. After injection of the sample, 1-NAA...
We describe in this report a method for determination of mesna and total mesna in urine by high performance liquid chromatography with ultraviolet detection. The method involves a treatment of the urine sample with tri-n-butylphosphine in order to convert mesna disulfides to its reduced counterpart mesna, ultraviolet labelling with 2-chloro-1-methylquinoluinium tetrafluoroborate, reversed-phase HPLC...
A prototype DRIFTS flow reaction chamber was designed and developed in order to find analytical application in the study of heterogeneous catalysts operating at high temperatures under fast transient gas feed conditions. Minimisation of dead-volumes allows gas replacement in 8–10s at 10mLmin −1 total flow. To overcome problems related to the reactivity of the cell walls under alternating oxidizing/reducing...
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