The dielectric ceramic materiala Ba(Zn1/3Ta2/3)O3–BaZrO3 has extremely low dielectric loss at microwave frequencies. To investigate the lattice vibrations of Ba(Zn,Ta)O3 and Ba(Zr, Zn, Ta)O3 solid solutions, far infrared reflection spectra were measured from 50 to 4000 cm−1 using a Fourier transform infrared spectrometer. These data were analyzed according to the classical dispersion theory. The spectra of Ba(Zn,Ta)O3 are well fitted by using the 14 resonant modes, and the spectra of Ba(Zr, Zn, Ta)O3 solid solution are fitted by assuming the normal distribution on resonant frequencies. The damping constant of these materials is discussed, and the values of tan δ calculated from the dispersion parameters agree with the measured values.

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Parts per billion amounts of heavy metal ions can be determined simultaneously by combining solvent extraction with microdroplet x‐ray fluorescence measurement. The use of diisobutyl ketone as a solvent for the extraction of heavy metal ions with sodium diethyldithiocarbamate is effective for improving detection limits in x‐ray analysis. A specially designed filter‐paper is used as a sample medium in the microdropler x‐ray fluorescence method and the volume of the droplets required for x‐rey measurements is only 20–100 m̈l. The detection limits of Mn, Fe, Co, Ni, Cu, Zn and Pb ions are 15, 16, 8, 8, 13, 13, 40 ppb, respectively, for a 100‐m̈l sample volume.