Achaeometrical Research in Hungary II., 1988

PROSPECTING and DATING - János CSAPÓ - Zsuzsanna CSAPÓ-KISS - János CSAPÓ JR.: How the amino acids and amino acid racemization can be used and with what limits for age determination of fossil materials in archaeometry

Table 12 Amino acid composition (g amino acid/100 g protein) of wool samples of Hungarian Merino sheep after various hydrolysis times Amino acids Hydrolysis time(hours) Amino acids 24

l 48

l 72 * 96

1 120

1 Cysteic acid 0.15 0.15 0.16 0.16 0.19 Aspartic acid (Asp) 7.3 7.4 8.0 8.3 8.3 Threonine (Thr) 6.2 5.9 6.0 6.1 6.2 Serine (Ser) 7.5 7.6 7.1 7.1 7.2 Glutamic acid (GIu) 11.3 12.7 15.0 15.4 15.5 Proline (Pro) 6.0 6.5 6.6 6.9 7.2 Glycine (Gly) 4.9 4.6 4.6 5.0 4.8 Alanine (Ala) 4.5 4.5 4.4 4.9 4.4 Cystine (Cys) 12.0 10.2 8.0 7.6 7.1 Valine (Val) 6.8 7.0 7.0 7.3 7.3 Methionine (Met) 0.4 0.5 0.4 0.3 0.4 Isoleucine (He) 3.3 3.6 3.7 3.5 3.2 Leucine (Leu) 7.8 8.2 8.2 7.9 8.4 Tyrosine (Tyr) 3.5 2.9 2.4 1.4 1.2 Phenylalanine (Phe) 4.2 4.2 4.0 4.0 4.1 Lysine (Lys) 3.5 3.2 3.2 Л 1 J.J 3.5 Histidine (His) 0.8 0.8 0.8 0.8 0.8 Arginine (Arg) 7.7 7.7 7.8 7.8 8.1 Ammonia 2.3 2.4 2.2 2.2 2.3 Number of the samples=3 3.3.2. Reliability of the analytical method Considering the enormous difficulties encountered in obtaining samples and the high value of the material to be subjected to analysis, a preliminary trial was conducted to assess the reliability and accuracy of analytical methods. The amino acid compositions of contemporary wool, a contemporary wool carpet and a 550-year-old wool carpet are shown in Table 13. Examining the amino acid compositions of contemporary wool and carpet, it is interesting to note that the fibres originating from the modem carpet contained twice as much cysteic acid and only 78% as much cystine as the virgin, untreated wool. The comparable differences with respect to the other amino acids were small. The situation changes substantially when we compare the composition of wool fibres from a 550year-old carpet with the mean composition of contemporary wool and carpet. The cysteic acid content of the ancient sample is strikingly higher than that in contemporary fibres (ca. 9 times). Also striking is the low cystine content, which is ca. one-third that of contemporary wools. The ancient wool fibre also contains more serine and glycine than contemporary samples. This may be correlated with the decomposition of cystine. Also worth 40