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

The wool samples were treated in the following manner. After having cleaned the samples (both ancient and contemporary) from mechanical impurities, the wool fibres were washed three times with 40-60 °C b.p. petroleum ether. During each washing the samples were left to soak in the ether for 20 minutes. Following this procedure, the samples were dried in a nitrogen current (15 minutes), and then washed three times with distilled water. The samples were left to soak for 20 minutes during each washing cycle. Following washing with distilled water, the samples were dried again in a nitrogen current. The dry samples were stored in airtight containers until the time of analysis. 3.2.2. Hydrolysis and processing of the hydrolysate Hydrolysis of the samples were performed in reusable Pyrex hydrolysis tubes (Pierce Chemical Company, Rockford, 111. U.S.A.). The tubes had an internal diameter of 8 mm and could accommodate 8 ml of hydrolysing agent so that the liquid was not in contact with the PTFE sealing ring. In the case of contemporary wool and carpets, 20 mg samples were introduced into the hydrolysing tube. In the case of samples coming from ancient wool carpets minimal sample size was 6.2 mg. Prior to use, the Pyrex hydrolysing tubes were washed twice with 6M hydrochloric acid and distilled water. After introducing the sample to be analysed, 5 ml of 6M HCl was added and nitrogen was bubbled through the tubes with the aid of a glass capillary for five minutes. Immediately after bubbling, the tubes were sealed and hydrolysis was begun at 110°C. After hydrolysis, the tubes were allowed to cool to room temperature. After the tubes were opened, pH of the hydrolysate was adjusted to a value of 2.2, using 4M NaOH. During pH adjustment, a 3salt/ice cooling mixture was used to maintain the temperature below 30°C. The resulting samples were diluted with a citrate buffer having pH=2.2. Samples were filtered and stored at 25°C until the time of analysis. Table 11 Carpets from the Hungarian National Museum Number of the sample Inventor y number Name of the sample Period (century) Age of the samples (years) Origin of the samples 2.19. 69/9158 carpet end of 16 400 Transylvania 2.20. 19487 carpet end of 17 300 from Teleki M. 2.21. carpet middle of 18 250 from China (Ningxia) 2.22. carpet beginning of 19 170 Anatolia, Balikesir 2.23. carpet from 1865 128 2.24. carpet 2

nd half of 19 120 Caucasus 2.25. carpet unknown unknown unknown From preliminary experiments, it seemed that the normal period of 24 hours was not sufficient for the complete hydrolysis of wool proteins. After only 24 hours hydrolysis, there were several ninhydrin positive peaks which were difficult to assign, but appeared to 58