Se, and Se were the isotopes monitored by this technique (reaction gas, CO; sample diluted 1 24; yttrium internal standard; quantification by standard addition) (5 ). Representative selenium concentrations measured in Seronorm Level 1 and 2 serum samples are shown in Table 1. Considering the Level 1 sample, all values from the three analytical techniques agreed (within quoted uncertainty ranges...

Forward osmosis (FO) requires a specific membrane structure for applications like juice concentration. The phase inversion method was used to make cellulose acetate (CA) FO membranes. solvents were acetone and 1,4-dioxane. Additives included polyvinylpyrrolidone (PVP), methanol, maleic acid in the preparation of CA membrane, which it easier improve membrane's permeability. performance fabricate...

Electrokinetic concentration devices based on the ion concentration polarization (ICP) phenomenon have drawn much attention due to their simple setup, high enrichment factor, and easy integration with many subsequent processes, such as separation, reaction, and extraction etc. Despite significant progress in the experimental research, fundamental understanding and detailed modeling of the preco...

Neutron activation analysis with an internal standard correction was applied to the determination of Cr and Co in a ceramics certified reference material (NMIJ CRM 8004-a silicon nitride powder). Cesium was used as an internal standard to compensate for any inhomogeneity of the neutron flux through an irradiation capsule and to improve the repeatability of gamma-ray measurements. It was found t...

Pressure retarded osmosis has the potential to utilize the free energy of mixing when fresh river water flows into the sea for clean and renewable power generation. Here, we present a systematic investigation of the performance limiting phenomena in pressure retarded osmosis--external concentration polarization, internal concentration polarization, and reverse draw salt flux--and offer insights...

In this paper, we report a novel method for fabricating ion-selective membranes in poly(dimethylsiloxane) (PDMS)/glass-based microfluidic preconcentrators. Based on the concept of capillary valves, this fabrication method involves filling a lithographically patterned junction between two microchannels with an ion-selective material such as Nafion resin; subsequent curing results in a high aspec...

This paper presents a bipolar electrode (BPE) device in a microfluidic dual-channel design for concurrent preconcentration and separation of composite DNA containing samples. The novelty of the present effort relies on the combination of BPE-induced ion concentration polarization (ICP) and end-labeled free-solution electrophoresis (ELFSE). The ion concentration polarization effect arising from ...

Silicon nitride layers can be deposited by a variety of methods leading to different physical characteristics, such as optical, electrical and mechanical properties. In photovoltaic applications highly hydrogenated (>20% H concentration) and transparent layers are necessary to passivate the surface (Seff <20 cm/s) while allowing for optimal internal quantum efficiency. Secondary properties, suc...

The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC,...

A comparison method for the determination (without sample pre-concentration) of uranium in ore by inductively coupled plasma optical emission spectrometry (ICP-OES) has been performed. The experiments were conducted using three procedures: matrix matching, plasma optimization, and internal standardization for three emission lines of uranium. Three wavelengths of Sm were tested as internal stand...