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Сообщение от Oleg Nazarov
isotopic analysis!
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in search of cheap chemical analysis at the age of painting in Germany, stumbled upon the isotopic analysis.
I was advised, quite seriously, a couple of laboratories which, by their occupations unrelated to the paintings do not. I called and asked the type that they themselves take so much. I was told that as half a century, there is absolutely confidential method for isotopic analysis of white lead. Academic method name: Pb-210. This method is available and laboratories without specialization. The logic is more reliable than the analysis of oil, although the principle is the same.
Half-life of Radium-226 is 22 years.
But interestingly different.
At my surprise the phrase "Oh ..: eek:." I was told that this is nothing new in there and museums in Europe regularly use this method. I asked, but as an auctioneer?
These guys are rare, reliable method for them like the plague.: D
Another method is for specialized laboratories, where the white lead analyzed for trace impurities. Analysis is interesting for European Painting 17 - 18 centuries. Raw material in those days were caught in good dozen mines in Europe and trace each mine, unique to this mine, are known. Interestingly, the famous 20 th century forgers were aware and knew where to dig.
Paintings fake Han van Meegeren, one of the most famous rigged the 20 th century gave the result: (Polonium-210: 8.5 ± 1.4, Radium-226: 0.8 ± 0.3). A picture Gollancz 1600 - 1660 gg. give an average (Polonium-210: 0.23 ± 0.27, Radium-226: 0.40 ± 0.47)
Difference as heaven and earth, while Han van Meegeren used raw material for white with the correct mine.
theses were defended on the subject in the mid 60s
Source: 3.Keisch, B: Dating Works of Art Trough their Natural Radioactivity: Improvements and Applications. In: Science, 160, p. 413-415, 1968.