Search results for "LIMIT"
showing 10 items of 2826 documents
Determination of triamterene in urine by HPLC using fluorescence detection and column-switching
1994
A liquid chromatographic method incorporating column-switching and fluorimetric detection for the determination of triamterene in untreated urine, is described. The urine samples (5 μL) were directly introduced onto an Hypersil ODS-C18, 30 μm (20 mm×2.1 mm I.D.) pre-column. Polar urinary compounds were removed by flushing the pre-column with water for 1 min, and the analyte was then switched onto an HP-LiChrospher RP C18,5 μm (125 mm×4mm ID) analytical column using an acetonitrile/phosphate buffer gradient elution. Fluorescence detection was performed at 230 nm excitation and 430 nm emission wavelengths. The recovery of drug was 102±2% in the 0.10–20.0 μg/mL concentration range, the limit o…
Chromatographic determination of diuretics in urine samples using hybrid micellar mobile phases with fluorimetric detection
1998
Abstract A rapid and simple chromatographic procedure, that uses hybrid micellar mobile phases of sodium dodecyl sulphate (SDS), propanol and phosphate buffer at pH 3, and fluorimetric detection ( λ exc =270 nm, λ em =430 nm), is reported for the determination of mixtures of seven diuretics of diverse efficacy (amiloride, bendroflumethiazide, bumetanide, furosemide, hydroflumethiazide, piretanide and triamterene), in urine samples. The application of a sequential optimization procedure for the resolution of the mixtures of the diuretics was problematic. However, their separation was achieved through the use of an interpretive optimization procedure based on the accurate description of the r…
Rapid determination of sterols in vegetable oils by CEC using methacrylate ester-based monolithic columns
2008
A method for the determination of sterols in vegetable oils by CEC with UV-Vis detection, using methacrylate ester-based monolithic columns, has been developed. To prepare the columns, polymerization mixtures containing monomers of different hydrophobicities were tried. The influence of composition of polymerization mixture was optimized in terms of porogenic solvent, monomers/porogens and monomer/crosslinker ratios. The composition of the mobile phase was also studied. The optimum monolith was obtained with lauryl methacrylate monomer at 60:40% (wt:wt) lauryl methacrylate/ethylene dimethacrylate ratio and 60 wt% porogens with 20 wt% of 1,4-butanediol (12 wt% 1,4-butanediol in the polymeriz…
Multivariate optimization of the hollow fibre liquid phase microextraction of muscimol in human urine samples.
2016
Abstract A liquid phase microextraction based on hollow fibre followed by liquid chromatographic determination was developed for the extraction and quantitation of the hallucinogenic muscimol from urine samples. Method applicability on polar hallucinogens was also tested on two alkaloids, a psychedelic hallucinogen, tryptamine and a polar amino acid, tryptophan which exists in its charged state in the entire pH range. A multivariate design of experiments was used in which a half fractional factorial approach was applied to screen six factors (donor phase pH, acceptor phase HCl concentration, carrier composition, stirring rate, extraction time and salt content) for their extent of vitality i…
On computation in the limit by non-deterministic Turing machines
1974
Analysis of β2-agonists in cattle hair samples using a rapid UHPLC–ESI–MS/MS method
2016
A simple and efficient method was developed for simultaneous analysis of five illegal residual β2-agonists in cattle hair. β2-Agonists were quantified by ultra high performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry operating in positive multiple-reaction monitoring mode. The method was validated as quantitative confirmatory method according to the EU Decision 2002/657/EC: instrumental linearity, specificity, precision, recovery, decision limit (CCα) and detection capability (CCβ) were evaluated. The recovery were greater than 90% and the method appeared suitable for the control of these β2-agonists in cattle hair samples with LOQ values between …
En lo que cabe and the limits of assertion
2019
El presente trabajo analiza la expresión en lo que cabe, construcción en proceso de fijación como operador discursivo que muestra cierta complejidad en su construcción y comportamiento macrosintácticos. Cumple algunos requisitos de los llamados operadores discursivos, pero coexiste con la construcción libre. Su valor es el de limitar una valoración y reducir la fuerza argumentativa de su alcance. Este contenido procedimental se desarrolla a partir del contenido semántico originario y de las funciones que cumple en el discurso. The present work analyzes the expression en lo que cabe, construction in process of fixation as discursive operator that shows certain complexity in its construction …
Ocho notas sobre la Casa Farnsworth de Ludwig Mies van der Rohe
2020
Mies was in the top of his career when he built the Farnsworth House. The analysis of this work shows some characteristics of his architectural thought: the relationships between architecture and nature, the definition of the pavilion type, his concept of architectural space, the role of structure and limits, the idea free plan and the meaning of construction
E. F. Schumacher : un precursor de la socioeconomía.
1994
Mercedes.Gomis@uv.es Jose.Perez@uv.es
Ultimate load analysis of plate foundations
1973
The behaviour of circular plates used as isolated foundations is investigated on the basis of earlier studies[6], [7] of the limit state of indefinite plates resting on elastoplastic continua and subjected to distributed loads. The upshot is an easy-to-use procedure of ultimate load analysis that permits the determination of: --the limit load for simultaneous collapse of plate and continuum --and the limit load for collapse of the continuum only according to the different behaviour of the two elements constituting the system.