Ammonia formation sediments

Koike, I., and Hattori, A. (1978) Denitrification and ammonia formation in aerobic coastal sediments. Appl. Environ Microbiol. 35, 278-282. 

Diamond occurring in the blue ground of volcanic pipes as well as freshly pulverized diamond show hydrophobic behavior. This is used in its isolation by flotation. Diamond found in sediments is hydrophilic, however. According to Plaksin and Alekseev (154), hydrophobic diamond turns slowly hydrophilic on storing with exposure to air. Hofmann (155) reported that fine particle size diamond forms stable suspensions in dilute ammonia after treatment with calcium hypochlorite. It seems rather obvious that formation of surface oxides is responsible for the hydrophilic properties. 

Alkali or ammonium chloride can be removed from the reaction mixture by sedimentation of filtration. Ammonia as base is definitely preferable in case of M(IV) derivatives to help avoid formation of stable bimetallic alkoxide derivatives [59], while Ln(0 Pr)3 and M (OR)s, M = Nb, Ta can be obtained in best yields using KOR because the bimetallic species with K are least stable thermodynamically [84]. 

---