Search results for "Diluent"
showing 10 items of 13 documents
Facilitated SLM extraction of peptides with D2EHPA as a carrier
2004
Abstract The extraction of short peptides through a supported liquid membrane containing di-2-(ethylhexyl)phosphoric acid (D2EHPA) as a carrier was investigated. The extraction was carried out from the aqueous donor phase with pH 3 to amore acidic acceptor phase. The proton gradient between the donor and the acceptor phase was the main driving force of the mass transfer in this system. The influence of various parameters such as diluent of the carrier, pH of the donor and acceptor phase, peptide structure and concentration on the extraction efficiency was presented.
PEMBEKUAN SEMEN LELE DUMBO (Clarias Gariepinus BURCHELL 1822) SEBAGAI MODEL KRIOPRESERVASI SEMEN IKAN
2010
<p><em>Effect of four types of diluents</em><em>s</em><em> and four concentration of DMSO (5%, 10%, 15% and 20%) against the motility of African catfish sperm were evaluated after storage at freezing temperatures. </em><em>The steps in preparation the 16 treatments combination of the diluents</em><em> </em><em>are </em><em>preparation of diluents, mixing </em><em>diluents </em><em>with DMSO, packing </em><em>of semen </em><em>in</em><em>to</em><em> 0.3-ml straw, equilibration of </em><em>semen </em><em>at 4 °C for…
Effects of ultrahigh dilutions of 3,5-dichlorophenol on the luminescence of the bacterium Vibrio fischeri.
2003
Abstract There is a great need for research in the field of homeopathy for laboratory test systems to investigate the actions of ultrahighly diluted biological effectors. With this in mind, we used the luminescent bacterium Vibrio fischeri, which is used throughout the world in testing water quality. Luminescence inhibition is utilized as a test parameter for the toxicity of a sample. We used ultrahigh dilutions (UHD) of 3,5-dichlorophenol as effector and adapted the standard test procedure for water toxicity in a way that let us evaluate very minute effects. Three groups of samples were prepared and then blinded: 45 dilutions of 3,5-dichlorophenol in steps of 10, starting with 4.2×10−2 M, …
Supported liquid membrane extraction with single hollow fiber for the analysis of fluoroquinolones from environmental surface water samples
2010
Abstract In this work, the simple analytical method for the determination of four fluoroquinolone antibiotics: ciprofloxacin, enrofloxacin, norfloxacin and danofloxacin, in environmental surface water samples is described. Sample pretreatment step was performed by the application of a technique based on supported liquid membrane extraction with the configuration of single hollow fiber (HF-SLM). The HPLC system with diode array detection was used for final analysis of studied analytes. Various parameters affecting the extraction efficiency during HF-SLM enrichment, such as type of membrane diluent, pH of donor (sample) and acceptor phases, as well as an enrichment time and salt content of sa…
Effect of diluent composition on the dynamics of sperm DNA fragmentation and other sperm quality parameters in ram during incubation at 37°C
2015
Abstract This study was conducted to assess the effect of different semen extenders on the dynamics of sperm DNA fragmentation (SDF) and other quality sperm parameters in ram. To this end, second ejaculates from 6 adult males were collected using an artificial vagina and diluted in either INRA-96 ® , milk, MOPS, TRIS, TES, HEPES, citrate or phosphate-based extenders. Semen samples were incubated at 37 °C and the SDF, motility and membrane integrity were assessed after 0, 3, 6 and 24 h intervals. Significantly higher SDF indexes were obtained at 6 and 24 h of incubation in the milk-based than in all the buffer-based extenders. At 24 h, sperm diluted in INRA also reached a higher SDF than MOP…
Substitution–dilution method to correct the matrix effect in multi-element quantitative analysis by X-ray fluorescence
2001
Abstract A mathematical model based on the dilution–addition method (DAM) for multi-elemental analysis using an X-ray fluorescence technique is proposed. The conditions for sample preparation do not require both the unknown and standard samples to be similar in composition and mineralogy, and the unknown sample is replaced quantitatively by the standard sample, hence the denomination substitution–dilution method (SDM). This method makes it possible to correct the matrix effect in multi-elemental quantitative analysis by X-ray fluorescence for each analyte. The proposed model presents hyperbolic behaviour of the experimental data when the X-ray fluorescence intensities are represented versus…
Combined effect of type and capture area of counting chamber and diluent on Holstein bull sperm kinematics
2018
The evaluation of sperm motion is crucial for processing of seminal doses for artificial insemination. Here, the combined effect of the type and capture area of three counting chambers, together with the type of diluent employed, on sperm motility was analysed. Ejaculates from thirteen Holstein bulls were used for sperm kinematic analysis with the ISAS® v1 CASA-Mot system, using two capillary-loaded counting chambers (Leja® and Cell-Vu® ) and one drop displacement chamber (Makler® ). Nine fixed positions were analysed per chamber type, considering central and lateral and three longitudinal fields. Independent of the diluent used, differences were found between the three chambers. Independen…
Inhomogeneity of gel and microsyneresis in porous styrene‐divinylbenzene copolymers
1985
The porosity of styrene-divinylbenzene copolymers prepared by suspension copolymerisation of the monomers carried out in the presence of inert diluent changes due to solvent pretreatment is investigated. The changes seem to reflect the inhomogeneity of copolymer gel. Various portions of it are transferred from the rubber-like into the glassy state at different stages of either swelling solvent exchange or the drying process. A microsyneresis, i.e. a local collapse of loosely crosslinked gel portions not followed by a shrinkage of the whole system, leads to the porosity changes.
Correction of Matrix Effect in Multielemental Quantitative Analysis by X-Ray Fluorescence Spectroscopy Using the Linear Behavior in the Analytical Ra…
2002
This paper is an analytical study of the possibility of applying the linear range of the substitution-dilution method to correct the matrix effect in quantitative analysis by X-ray fluorescence (XRF) spectroscopy. The analytical range is obtained from a series of samples prepared in the form of glass discs by substituting the unknown sample with a standard sample (substitution factor, h) including a diluent-melt. In general, the substitution-dilution method is hyperbolic in character and therefore the diluent is required to ensure linear behavior between If vs. h in the experimental range. The linear range is located between the concentrations of standard and unknown for each element analy…
Comparative Study of Different Column Types for the Separation of Polar Basic Hallucinogenic Alkaloids
2016
The number of hallucinogenic compounds that have been separated simultaneously by liquid chromatography is limited. This research aimed to identify a column(s) that can allow for separation of several hallucinogens. The extent of separation of seven polar hallucinogenic tryptamine and phenethylamine derived alkaloids containing a basic N atom that becomes protonated at low pH values were investigated on five reverse-based columns and one hydrophilic interaction liquid chromatography (HILIC) column. An RP-phenyl and a negatively charged fused core HILIC were identified and recommended as effective columns in this regard. This research is the first to introduce a HILIC column in separation of…