Isotopic analysis primarily involves the separation of isotopes based on the significant differences in mass. The method is effective for identifying the isotopic signature within the inorganic and organic compounds.
32S)
V-CDT − 1] × 1000, where V-CDT is the Vienna-Canyon Diablo Troilite standard) in lunar samples returned by the Apollo missions (
21). These studies found that lunar mare basalts, representing a range in major element compositions, have a remarkable uniform whole-rock acid-volatile (extraction with 3 M HCl) sulfur isotope ratios with a mass-dependent mean isotopic composition of δ
34S = +0.58 ± 0.05‰ (
2). This mean value is within the range measured for carbonaceous chondrites but is heavier than that reported for the Earth’s mantle (δ
34S = −1.28 ± 0.33‰) (
22), suggesting a different δ
34S value between the Earth’s and Moon’s interiors. A full compilation of mare basalt whole-rock δ
34S values, irrespective of the analytical technique used (different acid-volatile extraction, combustion in an oxygen atmosphere, or a combination of both), has a similar average but with a larger uncertainty (δ