Standardizing infra-red measures of bone mineral crystallinity: An experimental approach

Three experiments demonstrate that infra-red spectroscopic measures of bone mineral crystallinity are partially dependent upon sample preparation methods. Intensive grinding of bone samples for Fourier transform infra-red (FTIR) spectroscopic analysis results in a net decrease in splitting factor (SF), a common measure of apatite crystallinity. If grinding is overly intensive, SF measurement may respond more to variation in sample preparation than to the differences in bone mineral crystallinity that it is intended to monitor. Because even slight differences in sample preparation can affect SF values, a set of procedures and standards are proposed as a means of calibrating infra-red crystallinity measures.