Citrate Content of Bone: A Potential Measure of Postmortem Interval

Although this research involved three phases, only results from phase one are presented in this report. Phase one produced results from initial optimization and calibration studies and preliminary results from the analysis of fresh pig bone. From the calibration studies' results, the linearity of each method and linear range for each method was "quite good" and "more than adequate" for bone analysis of citrate. Considering that all fresh pig bone samples analyzed fell within the linear range of the methods, aged bone (not analyzed in this study) should also fall within the linear range of the methods, assuming that citrate content does decrease with increasing PMI. In the analysis of aged bone, the detection limits of the methods used must be considered. If a relationship between increasing PMI and decreasing citrate content is established from an analysis of aged bone, the rate at which the citrate decreases and the detection limits of the method will influence the useful range of PMI determination. The detection limit of the UV-Vis assay was approximately 4 mg of citrate; and for the HPLC method, 2 mg L-1 of citrate. Additional sample analysis with fresh pig bone is needed to fine tune sample preparation and establish a baseline value of citrate. This report describes the UV-Vis assay and the HPLC method. It also discusses the limitations of current methods for estimating PMI and the logic for the potential of measuring PMI by the citrate in bone. 3 tables, 2 figures, and 24 references