Determination of boron in nickel-base alloys by the dianthrimide method.
The dianthrimide method for the determination of boron in iron and low-alloy steels may be applied to nickel-base materials. The sample is dissolved, without any loss of boron, by hydrochloric and sulphuric acids and the resulting boric acid determined spectrophotometrically with dianthrimide. Background corrections are necessary to compensate for the absorbance from ions such as nickel and iron.
Application of Matrix-Assisted Laser Desorption and Ionization Time of Flight Mass Spectrometry to the Study of the Proteinaceous Binders in Paint: Blue Paint Composition in the Series “The Life of Virgin” by Alonso Cano (17th Century) as a Case Study
The identification of proteinaceous materials in paint constituents provides very valuable information regarding the techniques used by the painter and the most suitable procedures for conserving and restoring their works. Although the analysis of proteinaceous materials is nowadays a common task when dealing with works of art, the reliable detection and identification of protein traces is still complicated, particularly when very small samples can be taken that may contain a mixture of different organic materials (oils, waxes, resins, gums etc.). We therefore proposed a proteomic approach to investigate protein materials in paintings at trace levels in order to obtain a better understanding of the painter's technique. After trypsin digestion of the paint samples, mass spectra were obtained by matrix-assisted laser desorption and ionization time of flight mass spectrometry (MALDI-TOF-MS) and they were compared with the Mascot database and with theoretical digested proteins. This study contributes to the knowledge about the technique used by Alonso Cano (Granada, Spain, 1601–1667), one of the most original and brilliant artists from the Spanish Golden Age (17th century), in the series called the Life of the Virgin (six paintings), part of the iconographic program about the life of the Virgin Mary, nowadays seen in the main chapel of Granada Cathedral. The objective of the present study was to test the use of proteinaceous material, mainly egg yolk, in the paint used by Cano, as suggested in previous research, although this would have been unusual at that time when most artists used oil paints. Based on the results of the analysis here presented, the use of protein in the binding media can most likely be excluded.
Borsäure‐Bestimmung in pflanzlichen und tierischen Produkten
Es werden die verschiedenen Methoden zur Borsaure-Bestimmung und Veraschung von Substanzen auf ihre Brauchbarkeit zur Analyse pflanzlicher und tierischer Produkte untersucht. Die zur Analyse geeigneten Verfahren zur Aufarbeitung der Proben und zur Bor-Bestimmung werden genau beschrieben.