Investigation of red paint sample From an Egyptian artifact
Sample investigated
Title:
painted mummy shroud
Artist:
Unknown
Accession No.: 1973.4.503
Material:
Paint
Date/Provenance:
1st century AD Egypt
Plate 1
Experimental
LCMS analysis of the red pigment
A small sample of the red paint was hydrolysed in methanol with amberlite-15 acidic resin beads as
an acid catalyst for 2 hours. The mixture was filtered and subjected to LC-MS analysis using dilute
formic acid in methanol as one solvent and water as the other in a gradient elution. Analysis was
performed using a ThermoFinnegan Surveyor attached to a ThermoFinnegan LCQ Advantage ion trap
instrument operating in negative electrospray ionization mode. The parameters were optimized by
tuning the detector to the deprotonated quasimolecular ions of carminic Acid, Kermesic acid, Laccaic
acid A, Alizarin and purpurin.
Results
Total ion count
Purpurin
Alizarin
Kermisic acid
Relative Abundance
Carminic acid
Lacchaic acid A
RT: 0.00 - 12.06
0.45
100
NL:
7.45E5
TIC MS
Egyptian
Sample
Carminic
acid
95
90
85
80
75
70
alizarin
65
purpurin
60
4.41
55
50
5.45
45
40
35
0.37
3.32
30
3.19
25
10.15
3.72
3.85
1.70
20
8.56
4.12
0.56 0.85
15
6.56
0.91
10
1.57
4.92
2.87
1.83
1.17
5.05
5.63
8.48
7.63
6.96 7.36
7.68
9.09 9.14
9.54 9.89
9.01
10.20
10.60
11.74
11.13 11.48
8.16
6.30
2.10 2.37
5
0
0
1
2
3
4
5
6
Time (min)
7
8
9
10
11
Figure 1 Whole chromatogram (bottom) and individual detections for each compound by selected
ion monitoring above
12
LCMS
In the LC MS investigation Alizarin, purpurin and carminic acid were found,(Figure 1) which
indicates that the pigment is a mixture of madder lake and cochineal carmine.
Madder lake has been used as a pigment for a very long time
There are two varieties of cochineal which yield carminic acid as the main colourant and these are:
 American cochineal which was not available in Europe and the middle East until the late
15th century.
 Armenian Cochinial which may have been used at much earlier times. It has been used as a
textile dye, (see for example Cardon, D., 2007, , Judith Hofenk de Graff,2009) but little is
known of its use in pigments. This may have been confused with Kermes by historians who
do report that kermes lake was used in ancient Egypt (see for example Helmut Scheppe and
Heinz Roosen-runge , 1986)
References

Cardon, D., 2007, Natural Dyes-Sources, Tradition, Technology, Science, Archetype, London.

Hofenk de Graaf, J.H., 2009 The colourful past: The origins, chemistry and identification of na
tural dyestuffs, Archetype, London

Scheppe, Helmut and Roosen-Runge , Heinz, 1986, ‘Cochinial Carmine and kermes carmine
in Robert Feller (Ed.) Artists’ Pigments – A handbook of their History and
Characteristics.Cambridge.