The abundances of arsenic, tin and antimony in chondritic meteorites

Abstract Abundances of arsenic, tin and antimony in various classes of chondritic meteorites have been determined by neutron activation analysis. A simultaneous analytical procedure for As, Sn, and Sb was developed using anion-exchange chromatography in ammonium thiocyanate—hydrochloric acid media and was applied to the determination of these elements in a number of carbonaceous, enstatite, and “ordinary” chondrites. The results indicate that these elements are inhomogeneously distributed in some carbonaceous (Type I, II and III) and enstatite (Type A) chondrites. The average atomic abundances (Si = 10 6 ) of these elements are: As Sn Sb Carbonaceous chondrites (Type I) 5.4 3.5 0.33 Carbonaceous chondrites (Type II) 4.8 1.4 0.27 Carbonaceous chondrites (Type III) 4.9 1.3 0.20 Unequilibrated chondrites 1.8 0.74 0.14 Enstatite chondrites (Type A) 7.0 2.6 0.31 “Ordinary” chondrites (High Iron) 5.2 0.34 0.18 (Low Iron) 2.7 0.32 0.11 The observed atomic chondritic abundances are compared with the “cosmic” abundances in the odd-mass regions 63–81 and 105–127.