Multi-element profiling of human deciduous teeth by laser ablation-inductively coupled plasma-mass spectrometry

Abstract

The profiles of deposition of various metals in teeth have been obtained using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). This non-destructive technique, offers spatially resolved measurements of element distribution which can thus be related to a temporal axis via reference to the neo-natal line. Qualitative data affording comparison of elemental profiles between the teeth on a relative basis have been obtained. Owing to the lack of suitable qualified solid reference materials, quantitation has been attempted using a piece of walrus ivory. Average elemental concentration values were obtained by dissolution of a portion of sample followed by determination using ICP-atomic emission spectrometry giving a one point calibration for some 14 elements. These results were then related to the data counts obtained by LA-ICP-MS establishing a semi-quantitative relationship between the MS response and the elemental concentration in the sample. Measurements in different parts of deciduous teeth encompassing pre-and post-natal enamel, neo-natal dentine and circumpupal dentine reveal differences of deposition during the development period of the tooth. Evidence for the consistent incorporation of elements such as zinc and antimony is presented together with data for the occasional inclusion of chromium, iron and mercury. Trends in elemental deposition are also discussed.