Two forms of the solid byproduct from the use of hydroxyalkyl hexahydrotriazine as a hydrogen sulfide scavenger were investigated. The crystalline monomeric dithiazine and the intractable solid, known formerly as amorphous dithiazine. It was implied that the latter was simply another solid form of the same chemical species. The exact chemical structure and derivation of amorphous dithiazine were investigated in this study and the analytical data suggest that the material is polymeric in nature.

A gas chromatography−mass spectrometry method of assaying 1,3,5-tris(2-hydroxyethyl)hexahydro-s-triazine in laboratory and field fluids is presented. This method involves the tris-trifluoroacetylation of anhydrous 1,3,5-tris(2-hydroxyethyl)hexahydro-s-triazine to avoid the undesired thermolysis to oxazolidine.

Amorphous dithiazine is produced from a solution of tris-(2-hyroxyethyl)-hexahydro-s-triazine (I) that is heavily consumed by hydrogen sulfide (H2S). Previously, it has been reported that the chemical structure of amorphous dithiazine is a polymeric structure which involves opening of the dithiazine ring. Evidence is presented here that the first step in this polymerization reaction is conversion of the terminal hydroxyl functionality into a terminal thiol. Thereafter, the thiol initiates the ring opening of the dithiazine to yield a polymeric, highly insoluble material. It has been observed that the critical chemical species in the initiation of this chain reaction is the bisulfide anion. This bisulfide anion is produced from the reaction of H2S with ethanolamine liberated in the sulfur insertion reaction undergone by tris-(2-hyroxyethyl)-hexahydro-s-triazine (I). This process has been artificially induced by the reaction of monomeric or crystalline 5-hydroxyethyldithiazine (II) and ethanolammonium hydrosulfide.

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A gas chromatography−mass spectrometry method of assaying various thiadiazines and dithiazines in laboratory and field fluids is described. This method also involves the tris-trifluoroacetylation of anhydrous 5-(hydroxyethyl)dithiazine, which unexpectedly yields a novel derivative.