Track topics on Twitter Track topics that are important to you
A novel strategy is suggested for developing a size-exclusion chromatography (SEC) method in order to assess the molecular size distribution of natural organic matter (NOM). This strategy is based on the use of a chromatographic response function (CRF) and a response surface based on a central composite experimental design. The CRF qualifies the resolution degree attained under different SEC conditions with respect to global resolution of the chromatogram, number of distinguishable peaks, and analysis time. Based on a SEC study with a mixture of known organic compounds, predictive polynomial and linear models were developed according to the practice of design of experiments. Additionally, a chromatographic response surface was used, describing the effect of pH, amount of organic solvent, and salt concentration of the mobile phase on the values of the CRF. This new strategy predicted a single linear effect of salt concentration over the quality of the chromatographic separation, and the influence of this experimental variable on the quality of size-exclusion separations of various NOM samples was further discussed. For the analysis of NOM, the optimum settings for the mobile phase composition were as follows: pH 8.5, 11% of acetonitrile, and 15mM of sodium chloride. Under such analytical conditions, the measured molecular size distributions of water-soluble organic matter from atmospheric particles and aquatic fulvic acids compare reasonably well with the published molecular weight data. The newly developed strategy is a reliable alternative for accomplishing an accurate description of the size-exclusion profiles of NOM from different environments.
CESAM & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
This article was published in the following journal.
Name: Analytica chimica acta
Abstract Social exclusion is a painful experience. Recent research has shown, however, that coping with exclusion can be facilitated by favorable conditions. In the current research, we investigated w...
Polymer separations under non-conventional conditions have been explored to obtain a separation of long-chain branched polymers from linear polymers with identical hydrodynamic size. In separation med...
On page 1546, A. Mihranyan and team demonstrate for the first time a 100% natural, unmodified nanofibrous polymer-based membrane, capable of removing viruses solely based on the size exclusion princip...
Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and ...
A simple, yet efficient, two-column simulated moving-bed (2CSMB) process for purifying adenovirus serotype 5 (Ad5) by size-exclusion chromatography (SEC) is presented and validated experimentally, and...
Prospective, non-randomized trial to evaluate the safety and efficacy of the LAA Exclusion Device (Clip) for the exclusion of the LAA via epicardial tissue approximation.
PROTOCOL SYNOPSIS Title: Comparison of bivalirudin and unfractioned heparin (UFH)+ protamine in elective percutaneous coronary interventions (PCI) Design: Prospective, randomized, control...
The Bispectral Index monitor is used in many operating rooms to provide information to the anesthesiologist about a patient's level of consciousness. The Composite Variability Index, or Co...
Specific Aims: Environmental factors contributing to overconsumption, such as larger food portion sizes, may be contributing to the obesity epidemic. The objective of the proposed study ...
The aim of the present study is to evaluate the clinical, aesthetic and patient-centered parameters of connective tissue graft associated or not with composite resin for the treatment of g...
Abnormal anatomical or physiological conditions and objective or subjective manifestations of disease, not classified as disease or syndrome.
Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.
Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.
A nonspecific symptom of hearing disorder characterized by the sensation of buzzing, ringing, clicking, pulsations, and other noises in the ear. Objective tinnitus refers to noises generated from within the ear or adjacent structures that can be heard by other individuals. The term subjective tinnitus is used when the sound is audible only to the affected individual. Tinnitus may occur as a manifestation of COCHLEAR DISEASES; VESTIBULOCOCHLEAR NERVE DISEASES; INTRACRANIAL HYPERTENSION; CRANIOCEREBRAL TRAUMA; and other conditions.
Size, shape, and length of ECG parts, including waves, intervals, duration, and segments. Some heart-related conditions can be characterized by specific set of electrocardiogram patterns.
Latest News Clinical Trials Research Drugs Reports Corporate
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...