The presence of trace contaminants in ultra-pure water (UPW) used in fabrication process can greatly affect the yield and quality of industrial products. In the present study, the electrodialytic enrichment of metal cations as a means of continuously monitoring the UPW quality was studied. A newly designed electrodialytic enrichment device (EED) was used to quantitatively transfer metal ions from samples to dilute nitric acid, which was then directly introduced into an inductively coupled plasma—mass spectrometry (ICP–MS) instrument. This process could be performed without contamination of the sample, and the enrichment factor was solely dependent on the flow rate ratio of the sample and acceptor solutions. The transference of analytes into the acidic solution improved the responsivity of the ICP–MS analysis, especially at low concentrations of less than 1 μg/L. Blank solutions to support the analysis of UPW could be produced using the EED effluent, from which metal ions were quantitatively removed. In addition, calibration curves with concentration ranges of several nanograms per liter were obtained by preparing standards using a dynamic gravimetric method while employing a single bottle and continuous mass monitoring to avoid any contamination from the volumetric flasks. The sensitivities associated with the ICP–MS analysis of a number of trace metal ions were improved by one or two orders of magnitude. The data show that the present EED is able to continuously produce enriched analyte solutions to allow the ongoing monitoring of UPW quality.

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In this paper, we discuss the mechanism as well as the methodology of the La2O3 dissolution and its inhibition by functional waters. To clarify the mechanism, the La2O3 etching behavior in the various solutions, the surface state of La2O3 before and after cleaning, and the impact of functional water process on the electrical properties are evaluated. In order to control the La2O3 dissolution, a functional water process with a CO2 dissolved water as well as an ultra-diluted NH4OH have been developed. As a result of this study, it could be concluded that the pH control of the wet solutions plays an important role in terms of controlling the La2O3 dissolution.

The model of the molecular translocation of all types of DNA base molecules of cytosine, thymine, adenine and guanine through the nanoporous membrane of a solid thin film has been considered from the point of view of improving the resolution of forces by changing parameters of the membrane itself. The results of simulation of translocation process were compared for all four DNA nucleotides. The molecular dynamics (MD) method with the force field potential has been used for the atomic level modeling of the cytosine (C), thymine (T), adenine (A), and guanine (G) molecules and a configuration of the nanoporous Si membrane. With the planar structure of base molecules and cylindrical symmetry of pore, the two-dimensional projection was used in the simulation. The force field between the base molecule and atoms of nanopore has been estimated. Influence of the Si surface hydrogenization and film thickness on the force resolution for each nucleobase was evaluated vs. possible signal resolution. At 5 layer thickness of the film it was possible to cut thermal fluctuations and distinguish four nucleobase types.