Age estimation using aspartic amino acid racemization from a femur

Age estimation is an important step in post-mortem investigation, and the aspartic acid racemization (AAR) of dentin is the best tool for age estimation from human remains. However, teeth may not be found or sufficiently preserved to analyse the Dextro/Levo (D/L) ratio, and so age estimation using AAR from other organs, such as bones, is required. The current study evaluated age estimation methods using aspartic amino acid racemization from a femur in a Thai population. D/L ratio analysis using high-performance liquid chromatography (HPLC) was performed on 40 femoral bones from 24 males and 16 females, and the correlation between D/L ratio and age was 0.8316. The correlation coefficient in the male sample was greater than the female samples - 0.912 and 0.716, respectively. The standard error of estimation of all samples was 11.01 years. The correlation between the D/L ratio and the age of the total amino acid fraction from a femur was not as strong as from dentin and single protein purification, such as elastin and osteocalcin, but this method was necessary because teeth may not be found with body remains, and this method is not too complicated for routine forensic work.