Dissolution of Functional Materials and Rare Earth Oxides into Pseudo Alveolar Fluid

Abstract

The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron magnet alloy (NdBFe) and lanthanum-mish-metal-nickel-cobalt (LmNiCo) hydrogen-containing alloy. The dissolution rates of the rare earth oxides were very low, resulting in concentrations of rare earth elements in the test solutions of the order of ppb. In the most extreme case, Gamble's fluid dissolved 1,400 times more of the rare earth oxides than pure water. Fairly high concentration of neodymium were found in the dissolving fluids, which means that trace neodymium present as an impurity in each rare earth oxide dissolved preferentially. For yttrium oxide, the ratio of neodymium to yttrium that dissolved in the saline solution was greater than 78,000 to 1, taking into account the amount of each that was originally present in the yttrium oxide.

Evaluating the respiratory bioaccessibility of nickel in soil through the use of a simulated lung fluid

“…The method has also been applied to soils and dusts, such as radioactive uranium particles (Garger et al 2003) and lead in soils (Wragg and Klinck 2007). The original Gamble's solution was a mixture of water and inorganic salts including chlorides, carbonates, and phosphates, but the solution has been modified to include proteins and other organic components present in lung fluid (Takaya et al 2006). However, addition of proteins can affect experimental results and reproducibility due to degradation (Takaya et al 2006).…”

Characteristics of Multiwall Carbon Nanotubes for an Intratracheal Instillation Study with Rats

“…Sample preparation for SEM observation of fibers was described in detail in our previous paper 13) . Briefly, a water drop of MWCNT suspension at 533 m g/ml was put on a polycarbonate membrane filter (Isopore, Millipore, MA, USA) set on a suction filtration apparatus.…”

Pulmonary Toxicity Induced by Intratracheal Instillation of Coarse and Fine Particles of Cerium Dioxide in Male Rats

“…The sizes of Ce-C and Ce-F particles suspended in distilled water were determined by scanning electron microscopy (SEM). The solubility of Ce-F particles in pseudo alveolar fluid was determined by a method described by Takaya et al 19) .…”