Determination of thiourea and some of its organic derivatives with sodium vanadate, hexacyanoferrate(III), Cerium(IV) sulphate, manganese(III) and manganese(IV).
The determination of thiourea and some of its organic derivatives with sodium vanadate, hexacyanoferrate(III), cerium(IV) sulphate, manganese(III) and manganese(IV) is described. A mixture of iodate and iodide is used as catalyst. Ferroin, N-phenylanthranilic acid and p-ethoxychrysoidine can be used as indicators.
The role of manganese(IV) compounds as oxidants - a review.
A historical review of the development of manganese(IV) chemistry and its application in analytical chemistry is presented. A brief presentation of the presence and importance of manganese(IV) in other areas of chemistry is also given.
Dating of Historical Manuscripts Using Spectrometric Methods: A Mini-Review
An overview is provided of spectrometric methods useful for age estimation of historical manuscripts (medieval ones in particular), in order to confirm their authenticity. Individual methods (infrared and Raman spectroscopy, mass spectrometry, atomic emission spectroscopy, X-ray spectroscopy, and electron scanning microscopy) are discussed and examples of their application described. The following general strategy can be recommended for dating and/or authenticating of historical manuscripts. First of all, the pigment analysis should be carried out using Raman spectroscopy (distinguishing the period and modern pigments), followed by PIXE ink analysis (solving the question of ink homogeneity). Finally, the radiocarbon dating of the writing support, potentially supplemented by the ink dating using scanning Auger microscopy should be performed.