Stable isotope relationships between apatite phosphate (δ18O), structural carbonate (δ18O, δ13C), and collagen (δ2H, δ13C, δ15N, δ34S) in modern human dentine

Rationale The use of multi‐isotopic analysis (δ2H, δ13C, δ15N, δ18O, and δ34S values) of modern human body tissues for provenancing of unknown individuals in forensics is increasing. Tooth dentine develops during childhood and adolescence, therefore providing geographical information from that period of life. Tooth apatite δ18O values are commonly used for the reconstruction of drinking water values, and H–C–N–S isotope ratios in collagen supply additional information about the composition of diet. We tested if dentine collagen δ2H values provide similar information to apatite δ18O values with a proof‐of‐concept study. Methods Tooth samples were taken from modern‐day individuals born in different regions of the world. Apatite and collagen were prepared from dentine. Stable isotope analyses were performed on apatite phosphate oxygen (δ18Ophos); oxygen and carbon of the structural carbonate (δ18Ocarb, δ13Ccarb); and hydrogen, carbon, nitrogen, and sulfur of the collagen (δ2Hcoll, δ13Ccoll, δ15N, δ34S). Results δ18Ophos, δ18Ocarb, and δ2Hcoll values are highly correlated in modern human dentine. There are significant relationships of δ18O values in the apatite fraction and δ2H values in the collagen fraction with local δ18O and δ2H precipitation values, respectively. Pearson correlation coefficients indicate no direct relationship between δ15N values and the isotope ratios of any other element. Weak relationships exist between collagen δ34S values and δ18Ocarb or δ18Ophos values. Conclusions The highly significant correlation of δ18Ophos, δ18Ocarb, and δ2Hcoll values in the modern human dentine implies that measurement of δ2H values in collagen or δ18O values in bioapatite will provide reliable information about the climate at the person's whereabouts