Determination of phosphorus in palaeosediments using portable X-ray fluorescence spectrometry

Abstract

Phosphorus (P) is an important chemical marker of the past human presence, because, besides indicates the localization of possible archaeological sites, also, contributes to clarify doubts regarding to origin, duration and to specific functions that were developed in them. The present study aimed to obtain a simple, accurate, fast and non-destructible analytical method to determine phosphorus in sediment samples of the Toca da Baixa dos Caboclos archaeological site, an enclave of the Serra da Capivara National Park, Piauí, Brazil. For the proposed method, a portable energy dispersive X-ray fluorescence (p-ED-XRF) equipment and cross calibration to sample direct analysis were used. The results show that the concentrations obtained by the proposed method, cross calibration with use of p-ED-XRF, and by the spectrophotometric method were considered statistically equal, when compared by the paired t test (p=0.05). By its turn, the intermediate accuracy and recovery tests showed values in the range of 2.41−3.56% and 85.10-102.66%, respectively.