A rapid, reproducible, and sensitive procedure for the determination of phosphate in several biologic materials is described Organic phosphate is rapidly converted to orthophosphate by digestion with a nitric acid-calcium ion mixture. The acid destroys the organic material while the calcium ion prevents loss of phosphate or its conversion to an unmeasurable form. Inorganic phosphate can be dete...

Titania supported vanadomolybdophosphoric acid (VMPA) catalysts with vanadium in different positions, incorporated into the molybdophosphoric acid structure by substituting for molybdenum and cation exchanged on the molybdophosphoric acid surface, were synthesized. The catalysts were characterized by XRD, FT-IR, Raman spectroscopy, TPR, XPS, and ESR techniques. The FT-IR and Raman spectral anal...

A novel micro-stepwise injection analyzer (μSWIA) has been developed for the automation and miniaturization of spectrophotometric analysis. The main unit of this device is a mixing chamber (MC) connected to the atmosphere. This part of the μSWIA provides rapid and effective homogenization of the reaction mixture components and completion of the reaction by means of gas bubbling. The μSWIA conta...

The structures of condensed tannins isolated from two mangrove species, Kandelia candel and Rhizophora mangle, were characterized by 13C nuclear magnetic resonance (NMR) spectroscopy and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. Results demonstrate that large heterogeneity occurs in degree of polymerization, pattern of hydroxylation, a...