Baseline Assessment for the Consistency of Raman Shifts Acquired with 26 Different Raman Systems and Necessity of a Standardized Calibration Protocol.

Although Raman shifts originate from molecular vibrations and in theory must be independent of analytical systems, acquired Raman shifts, in practice, are not so. Since the consistency of Raman shifts acquired with different systems has not been investigated previously, we have compared the Raman spectra of polystyrene, benzonitrile, and cyclohexane obtained with 26 different systems. The medians of 26 measurements for the characteristic peaks were found to be 1001.

[Interlaboratory Study on Evaporation Residue Test for Food Contact Products (Report 2)].

An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using heptane as a food-simulating solvent for oily or fatty foods, based on the Japanese Food Sanitation Law for food contact products. Twenty-three laboratories participated, and tested the evaporation residues of nine test solutions as blind duplicates. In the official method, heating for evaporation was done with a water bath.

[Interlaboratory Study on Evaporation Residue Test for Food Contact Products (Report 1)].

An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using three food-simulating solvents (water, 4% acetic acid and 20% ethanol), based on the Japanese Food Sanitation Law for food contact products. Twenty-three laboratories participated, and tested the evaporation residues of nine test solutions as blind duplicates. For evaporation, a water bath was used in the official method, and a hot plate in the modified method.

A practical evaluation of measurement uncertainty in gamma-ray efficiency curve determination through an analytical approach.

An example of uncertainty evaluation of an efficiency curve is reported. In the applied method, the efficiency curve is determined through the weighted least square method based on measured efficiencies employing a mixed-radionuclide standard source. The variance-covariance matrix of the efficiencies is determined by evaluating the uncertainties of the counting, the calibrated radioactivities, the correction factors for true coincidence summing, and the inadequacy of the fitting function.

[Interlaboratory Study on Caprolactam Test for Food-Contact Nylon Products].

The Japanese Food Sanitation Law sets a limit on the migration level of caprolactam for food-contacting nylon products. Here, we carried out an interlaboratory study in twenty laboratories to evaluate the performance of the official GC-FID test method and a GC-MS method as an alternative test method to the official method. Each laboratory quantified caprolactam in three test solutions in 20% ethanol as blind duplicates using GC-FID or GC-MS.

[Interlaboratory Study on Zinc Test for Food-Contact Rubber Products].

Using six kinds of zinc solution in water and 4% acetic acid as samples, an interlaboratory study was performed to evaluate a zinc (Zn) test method for food-contact rubber products, based on the Japanese Food Sanitation Law. Eighteen laboratories participated, and quantified Zn in six test solutions as blind duplicates using flame atomic absorption spectrometry, induced coupled plasma-optical emission spectrometry or induced coupled plasma-mass spectrometry. Statistical analysis revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 97-103%, 0.

[Interlaboratory study on migration test of antimony and germanium for food-contact polyethylene terephthalate].

An interlaboratory study was performed to evaluate a migration test method of antimony (Sb) and germanium (Ge), based on the Japanese Food Sanitation Law for food- contact polyethylene terephthalate. Eighteen laboratories participated, and quantified Sb and Ge in three test solutions as blind duplicates using graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma-optical emission spectrometry (ICP-OES) or induced coupled plasma-mass spectrometry (ICP-MS). Statistical analysis revealed that the trueness, repeatability and reproducibility were 98-107%, 1.

Molecular simulation of ion transport in silica nanopores.

Ion distribution and transport of KCl aqueous solutions at the junction of hydrophobic and hydrophilic regions inside silica nanopores were studied by using two kinds of molecular simulation: grand canonical Monte Carlo (GCMC) simulations and nonequilibrium molecular dynamics (NEMD) simulations. The nanopores were 2 nm diameter silica pores in which surface functional groups, -SiOH, had been modified by hydrophobic surface functional groups, -SiCH(3), within three different lengths along the pore direction (z-direction), L(z0) = 0, 2, and 4 nm. If L(z0) is long enough, water could not enter the hydrophobic region, but for all L(z0) studied here, water entered the hydrophobic region.

Molecular dynamics study of hydrated faujasite-type zeolites.

Molecular dynamics (MD) simulations of hydrated zeolite NaX (Si/Al = 1.0) and NaY (Si/Al = 2.0) were done at a temperature of 300 K.

Nanofluidic diode and bipolar transistor.

Theoretical modeling of ionic distribution and transport in a nanochannel containing a surface charge on its wall, 30 nm high and 5 microm long, suggests that ionic current can be controlled by locally modifying the surface charge density through a gate electrode, even if the electrical double layers are not overlapped. When the surface charge densities at the right and left halves of a channel are the same absolute value but of different signs, this could form the basis of a nanofluidic diode. When the surface charge density at the middle part of a channel is modified, this could form the basis of a nanofluidic bipolar transistor.