Characterization of Prussian blue and its thermal decomposition products

The mixed-valence state of Prussian blue and its thermal decomposition products has been studied by Mössbauer and infrared spectra, and X-ray powder diffraction and conductivity measurements. The⁵⁷Fe Mössbauer spectra have revealed that the coordination environment of Prussian blue is not changed by the heat-treatment at lower than 200°C while the flipping of the cyano ligands takes place when the heat-treatment temperature exceeds 250°C. The electrical conductivity of the Prussian blue samples heat-treated in vacuo at 300 and 350°C is higher than that of the samples heat-treated at lower temperatures. All the spectral measurements have demonstrated that a new mixed-valence state is produced in Prussian blue by thermally flipping the cyano ligand and quenching the flipped cyano ligand to liquid nitrogen temperature.     

Determination of 1-hydroxypyrene in human urine by high-performance liquid chromatography with fluorescence detection using a deuterated internal standard

A high-performance liquid chromatographic method has been developed for the quantification of 1-hydroxypyrene (1-OHP) in human urine using deuterated 1-hydroxypyrene ([2H9]1-OHP) as an internal standard with fluorescence detection. [2H9]1-OHP was prepared enzymatically from deuterated pyrene ([2H10]Pyr) with cytochrome P450 1A1. It eluted immediately prior to non-deuterated 1-OHP on alkylamide-type reversed-phase columns and had nearly the same fluorescence characteristics as non-deuterated 1-OHP. The detection limit was 0.1 microg/L and the calibration range was from 1 to 100 nmol/L. Urine sample treatment involved enzymatic hydrolysis followed by solid-phase extraction using Sep-Pak C18 cartridges. The proposed method was used to determine urinary 1-OHP in smokers and non-smokers.