Separation of strontium from calcium by means of anion exchanger and alcoholic solution of nitric acid

Study on the removal of interferences for the determination of ⁸⁷Sr/⁸⁶Sr isotopic ratio in petroleum drill-hole water samples using isotope dilution – inductively coupled plasma mass spectrometry (ID – ICP-MS)

“…Previous report in literature [17] showed that the distribution constant of calcium on anionic exchanger much lower than that of strontium in alcoholic medium. Several cations can adsorb on strong base anion exchange resins, which contain the quaternary ammonium group with nitrate as counter-ion from solutions of nitric acid in alcohol [14] and the order of adsorption of these cations depends on the distribution coefficients [13,14].…”

“…There exists several resolutions to correct the signal value for these two isotopes by using 85 Rb and 88 Sr [10,11] but the complete removal of Rb from Sr in analyzed sample is preferable with the use of ion-exchange chromatography [1,3,7,[9][10][11][12]. In case of sample containing thick matrix due to high concentration of calcium and other alkaline earth elements such as rock or soil, it is necessary to remove these interfered major elements before the separation of strontium and rubidium [7,[10][11][12][13][14][15][16][17]. The removal of calcium from sample matrices, especially from seawater was carried out with variety of reagents using solvent extraction or fractional precipitation or ion exchange [6,8,[15][16][17].…”

“…In case of sample containing thick matrix due to high concentration of calcium and other alkaline earth elements such as rock or soil, it is necessary to remove these interfered major elements before the separation of strontium and rubidium [7,[10][11][12][13][14][15][16][17]. The removal of calcium from sample matrices, especially from seawater was carried out with variety of reagents using solvent extraction or fractional precipitation or ion exchange [6,8,[15][16][17]. Among them, the ion exchange technique was recently more applicable to separate calcium from different sample matrices [13][14][15][16][17] with high recovery of strontium.…”

“…The removal of calcium from sample matrices, especially from seawater was carried out with variety of reagents using solvent extraction or fractional precipitation or ion exchange [6,8,[15][16][17]. Among them, the ion exchange technique was recently more applicable to separate calcium from different sample matrices [13][14][15][16][17] with high recovery of strontium. Since calcium and strontium are adjacent elements in alkaline earth group with similar physical and chemical properties, the quantitative separation of each other is rather difficult even using ion exchange technique, except for the use of special resin to separate 90 Sr trace from seawater [18].…”

Isolation of radioactive strontium from natural samples: A semi-automatic procedure

“…The concentration ratio of calcium and strontium does not affect their mutual separation. 23 From the practical point of view, it should also taken into consideration that strontium should be isolated as quickly as possible, so that the possible eluent is only 0.25M HNO 3 in methanol, or in the mixture of ethanol and methanol. Other alcohols cannot be used because of an excessive intensity of strontium adsorption on the exchangers and of a low solubility of their nitrate salts.…”