Determination of elements in human femoral bone using inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry

Abstract

A method is described for the measurement of a range of elements in human bone to examine whether changes occur in composition to cause fracturing. Samples were taken from the neck of femur, and adhering tissue and fat were removed using a hydrogen peroxide–ethanol wash procedure and the cleaned, dried bone was dissolved in a mixture of mineral acids (1 + 1 HNO₃–HCI). Al, B, Ca, Fe, K, Mg, Na, P, Pb, Sr and Zn were determined quantitatively by inductively coupled plasma atomic emission spectrometry or inductively coupled plasma mass spectrometry. Accuracy and precision were tested by analysing a Community Bureau of Reference bone reference material (not certified). The values obtained were in good agreement with reported values for this material and precision of measurement was acceptable, typically between 2 and 10% relative standard deviation. Inhomogeneity of the bone samples was found to be a potential limiting factor in the interpretation of data from different patient groups. In the analysis of bone material the sampling site can be a critical factor and care was taken to ensure that each patient's bone sample was obtained from the same site. From a comparative analysis there was no clear evidence of any differences in the composition of both major and trace elements in femoral bone from post-mortem but previously healthy controls (n= 13), osteoarthritic (n= 21) or patients with fracture of the head of femur (n= 20), e.g., Ca, 247 ± 29; 248 ± 58; 211 ± 48 mg g^–1; P, 115 ± 9; 116 ± 29; 99 ± 38 mg g^–1; and A1, 19 ± 5; 18 ± 10; 22 ± 12 µg g^–1; mean ± 1 s, respectively. However, Pb was significantly lower in osteoarthritic bone, viz., 7 ± 7 µ g^–1 compared with the other groups, viz., 14 ± 9 µg g^–1, possibly indicating the increased bone turnover in this condition. The explanation for the tendency to fracture femur bone appears not to be related to any abnormality in bone composition.