A standardless approach of INAA for grouping study of ancient potteries K. B. Dasari • R. Acharya • N. Lakshmana Das • A. V. R. Reddy Received: 26 September 2011 Ó Akade ´miai Kiado ´, Budapest, Hungary 2011 Abstract The k 0 based internal monostandard neutron activation analysis was used to analyze 41 ancient pottery samples from three major locations of Andhra Pradesh state, India, belonging to two different age groups namely Megalithic and Buddhist periods. Samples were irradiated with neutron flux obtained from CIRUS reactor and radioactive assay was carried out using a 40% relative efficiency HPGe detector coupled to 8 k MCA. Concen- tration ratios of 21 elements were calculated with respect to internal monostandard Sc. Absolute concentrations for six (three each from both Megalithic and Buddhist periods) representative samples along with a modern pottery were obtained for comparison. Elemental concentration ratios with respect to Sc were used for grouping of these archaeological samples. Preliminary grouping of these artifacts was done using La/Ce values, and the grouping was confirmed by statistical cluster analysis using eleven selected trace elements. The IAEA RM SL-3 sample was analysed for validation of the method, where in both concentration ratios and absolute concentrations were calculated. Keywords Archaeological artifacts  Clay pottery  INAA  Internal monostandard method  Cluster analysis  Grouping study Introduction Archaeologists have keen interest on archaeometry of ancient artifacts since 1957 to get the information about ancient people activities, culture, technology of preparation, exchange pattern, art and trade [1, 2]. Ancient artifacts like potteries, bricks, stones, coins and paintings are mostly studied, and among these potteries are widely studied since they are most abundantly available in all excavated archae- ological sites. Archaeologists are often interested for the provenance of the artifacts to establish whether the artifacts under study are of same or different origin/source. Classifi- cation of pottery samples according to their physical char- acteristics like decoration and style is carried out to categorize into groups [3, 4]. The microscopic properties like chemical composition is most widely used in the provenance studies since it carries chemical ‘‘fingerprinting’’ and expected to have a correlation from which the sample under study was made. The chemical composition of pottery is strongly related to the source of clay and recipe of the making [5]. It is known that the concentrations of major elements in different pottery samples may not vary signifi- cantly compared to trace elements. The trace elements are source specific and thus provide best information for grouping study [3]. The elements having non volatile or immobile or similar geochemical properties are chosen for grouping study. The elements include Cr, Sc, Fe, Co, Zn, Rb, Cs, La, Ce, Eu, Yb, Lu and Hf. Preliminary grouping is done through Al/Sc (non-volatile properties) or La/Ce (similar geochemical properties) [6] and confirmation of grouping is K. B. Dasari  R. Acharya (&) Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India e-mail: racharya@barc.gov.in K. B. Dasari  N. L. Das GITAM Institute of Science, GITAM University, Visakhapatnam 530 045, India e-mail: nldas9@gmail.com A. V. R. Reddy Analytical Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India 123 J Radioanal Nucl Chem DOI 10.1007/s10967-011-1464-5