Micro‐invasive method for studying lead isotopes in paintings*

Abstract

A micro‐invasive technique is presented that enables pigment sampling from individual layers of a painting cross‐section by obtaining a furrow 10–50 μm wide of chosen length. Combined with increased sensitivity of lead (Pb) isotope analysis using multicollector inductively coupled plasma mass spectrometry (MC‐ICPMS) equipped with a 1013 Ω resistor or a Pb double‐spike technique, the amount of Pb needed for isotopic analysis is drastically reduced, while maintaining a relative 2 SD precision for 206Pb/204Pb of < 0.02%. The methodology proved able to characterize Pb isotope differences within paint layers.

Beauty is skin deep: the skin tones of Vermeer’s Girl with a Pearl Earring

“…Specific layers within cross-sections from Girl with a Pearl Earring were sampled for lead isotope analysis using a custom-designed microsample tool, which extracted microscopic samples containing lead white (5 to µg) [38]. In total, eight different lead white-containing paints were analysed, originating from the ground, upper layers and underlayer(s) in the light and dark parts of the Girl's skin.…”

“…Small quantities of material were extracted from embedded cross-sections using a micro-scalpel: a purpose-designed tool developed for the purpose of micro-invasive sampling of cross-sections [38]. The micro-scalpel uses a blade that allows the operator to sample specific layers of a cross-section with a minimum thickness of 10 µm.…”

Time-dependent variation of lead isotopes of lead white in 17th century Dutch paintings

“…Following the procedure described by D’Imporzano et al . ( 14 ), the lead white pigment samples were obtained from cross sections using a microscalpel. This method allows sampling individual paint layers of a cross section between 10 and 50 μm in width.…”

“…In the last decades, lead isotope analysis of lead white ( 6 – 8 , 14 , 15 ) focused on the following: (i) the place of origin of the lead ore, i.e., its provenance ( 5 , 7 , 8 ); (ii) identification of paintings according to artistic groups ( 7 , 8 , 15 ); (iii) investigating the composition/variation of lead isotope of lead white within a single painting ( 6 ); and (iv) authentication of paintings, as in the case of the attribution of a copy of Saint Praxedis to Vermeer ( 16 , 17 ) or the attribution of Michiel Sweerts paintings to his period in Rome ( 18 ). Most recently, lead isotope analysis of lead white has also been coupled with the study of 14 C of the carbonate for dating purposes ( 15 , 19 ).…”

Identification of a female murder victim found in Burgenland, Austria in 1993

“…A session of Pb isotope measurements typically consisted of 10 samples, two in-house standards, 14 NBS SRM-981 standards, and 27 blank measurements. The long-term average Pb isotope data of a 100 ppb solution of the CPI International standard, including the values for the analytical session that produced data for this report, are reported in D'Imporzano et al [21].…”