Document Detail

Animal urine as painting materials in African rock art revealed by cluster ToF-SIMS mass spectrometry imaging.
MedLine Citation:
PMID:  20665601     Owner:  NLM     Status:  MEDLINE    
The rock art site at the village of Songo in Mali is a very important Dogon ritual place where, since the end of the nineteenth century until today, takes place the ceremony of circumcision. During these ceremonies, paintings are performed on the walls of the shelter with mainly three colors: red, black and white. Ethnological literature mentions the use of animal urine of different species such as birds, lizards or snakes as a white pigment. Urine of these animals is mainly composed of uric acid or urate salts. In this article, time-of-flight secondary ion mass spectrometry (ToF-SIMS) is used to compare uric acid, snake urine and a sample of a white pigment of a Dogon painting coming from the rock art site of Songo. ToF-SIMS measurements in both positive and negative ion modes on reference compounds and snake urine proved useful for the study of uric acid and urate salts. This method enables to identify unambiguously these compounds owing to the detection in negative ion mode of the ion corresponding to the deprotonated molecule ([M-H](-) at m/z 167.01) and its fragment ions. Moreover, the mass spectra obtained in positive ion mode permit to differentiate uric acid and urate salts on the basis of specific ions. Applying this method to the Dogon white pigments sample, we show that the sample is entirely composed of uric acid. This proves for the first time, that animal urine was used as a pigment by the Dogon. The presence of uric acid instead of urate salts as normally expected in animal urine could be explained by the preparation of the pigment for its application on the stone.
Vincent Mazel; Pascale Richardin; David Touboul; Alain Brunelle; Caroline Richard; Eric Laval; Philippe Walter; Olivier Laprévote
Publication Detail:
Type:  Historical Article; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of mass spectrometry : JMS     Volume:  45     ISSN:  1096-9888     ISO Abbreviation:  J Mass Spectrom     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-08-31     Completed Date:  2010-12-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9504818     Medline TA:  J Mass Spectrom     Country:  England    
Other Details:
Languages:  eng     Pagination:  944-50     Citation Subset:  IM    
Copyright Information:
Copyright 2010 John Wiley & Sons, Ltd.
Laboratoire du Centre de Recherche et de Restauration des Musées de France (LC2RMF), CNRS UMR 171, Palais du Louvre, Porte des Lions, 14 quai François Mitterrand, 75001 Paris, France.
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MeSH Terms
History, 19th Century
History, 20th Century
Paint / analysis*
Paintings / history*
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
Uric Acid / chemistry*
Urine / chemistry*
X-Ray Diffraction
Reg. No./Substance:
69-93-2/Uric Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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