Determination of Strontium by ICP-MS and a Study of the Influence on Native Elements in Incisors of Rats

Strontium malonate is a new promising agent for osteoporosis treatment. Strontium malonate combines the beneficial effect of strontium ions together with an improved biological absorption. Our aim was to assess the effect on mineralize tissue composition of 6 months therapy of strontium malonate in rats. The effects were monitored on calcium, magnesium and phosphorous that key elements in the apatite crystal in 160 rats treated with 0, 100, 300 or 1000 mg/kg/day strontium malonate for 6 months by oral gavage. After termination femurs and incisors were excised and after thorough rinsing, digestion was conducted under controlled hydrothermal conditions. The elements Ca, Mg, Na, P and Sr were quantified in all samples by ICP-MS, from working curves containing up to 20 calibration points, and the measurements were validated on NIST SRM 1486 and 1640. The ability to incorporate strontium in bone and the influence on the other elements as a function of dose was first evaluated by Principal Component Analysis and then by a two-way ANOVA. Strontium incorporation in bone was dose dependant on with the highest dose appearing to be close to saturation levels. A significant difference between male and female as a function of strontium dose was discovered. At the highest doses, it was found that strontium significantly altered the concentrations of Ca, Mg, and P in the mineralized matrix. The results suggest that strontium malonate should be administered in quantities within certain limits for the treatment of metabolic bone diseases, which need to be assessed in forthcoming trials.