Infrared spectra of some matrix-isolated germanium,tin, and lead chalcogenides

Infrared spectra are reported for GeS, GeSe, GeTe, SnS, SnSe, PbS and PbSe in argon and nitrogen matrices at 12°K. The absorptions due to the matrix-isolated diatomic IV–VI molecules show considerable isotopic structure. The dimer absorptions are treated in terms of a D_2h planar model and indicate that the dimers have nearly square geometries and that the bond stretching force constants in the dimers are about half those of the diatomic molecules.     

Selective catechol oxidations with diphenyl selenoxide. Applications to phenolic coupling.

Diphenyl selenoxide was used as a mild and selective oxidant in the synthesis of aporphines and homoaporphines. An intramolecular coupling between a phenol and a catechol is believed to proceed $\text{via}$ catechol selenurane intermediates.     

Solid phase extraction and high performance liquid chromatographic determination of doxophylline in plasma

A sensitive and selective high performance liquid chromatographic doxophylline assay with ultraviolet detection has been developed for plasma samples. The drug is isolated from biological samples with a reversed phase C18 disposable extraction column. Plasma standard curves are linear for concentrations of doxophylline from 0.03 to 10 mg/L. At the therapeutic range concentrations, the recoveries are better than 96.9%. The coefficients of variation for the procedure are 4.1% and 2.7% for the concentrations 0.03 mg/L and 10 mg/L, respectively. By this method, pharmacokinetic profiles are obtained for six adult volunteers.