The Retention of Six-, Seven-, Eight-, and Twelve-Membered Ring Molecules of Type SexS y in Reversed-Phase HPLC. Prediction of Retention for Unknown SexS y Heterocycles and Analysis of Sulfur-Selenium Melts

The HPLC retention times of 25 cyclic compounds of type Se Sy, (x = 0 · · · 8; y = 0 · · · 12) have been measured under identical conditions and are used to evaluate the factors which determine the retention. Linear relationships are derived for the dependence of retention (Ink'; k′ = capacity factor) on ring size, number of Se atoms, and number of SeS bonds per molecule for six-, seven-, eight-, and twelve-membered Se rings. These relationships allow the prediction of retention times for all Se heterocycles of these ring sizes (ca. 100 compounds). The results are applied to the qualitative analysis of mixed sulfur-selenium melts of two compositions: at a molar ratio of S : Se = 8.7 twenty-one HPLC signals have been observed for the CS extract of the quenched melt and assigned to Se rings of sizes 6··· 12. At S : Se = 0.33 mainly six-, seven-, and eight-membered species with cumulated Se atoms have been found.