Abstract
(1) The Russell effect from raw rubber, after exposure to light and air, depends on three factors: (a) smoke components: smoked sheet shows a strong Russell effect owing to the presence of these components; Para does not because it is prepared with a different kind of smoke; (b) tackiness: most crepes show little Russell effect, but prolonged exposure after acetone extraction causes concurrent increases in both the Russell effect and tackiness; (c) acetone extract: the extract shows a strong Russell effect, but this is scarcely apparent when it is present in the rubber. (2) The gaseous products that cause the Russell effect are decomposed or driven off at 80° C. (3) These gaseous products are not the same as those formed by treatment with ozone. (4) Antioxidants for raw rubber do not affect the Russell effect, but sodium bisulfite weakens it. (5) Mastication or mixing with sulfur alone has little effect, but mixing with diphenylguanidine, triphenylguanidine or hexamethylenetetramine plus sulfur, or with mercaptobenzothiazole alone, considerably weakens the Russell effect. (6) Vulcanized rubber (normally or overcured, or oxidized by aging) shows a very weak Russell effect; this effect therefore will not detect incipient oxidation or a tendency to oxidation. (7) Quartz mercury vapor lamps are not suitable for experiments on the Russell effect, because the results are complicated by the ozone formed around them. (8) Ozone, even in very low concentrations (0.01 per cent or less), causes a strong Russell effect in both raw and vulcanized rubber.
Urinary Excretion of Mercury from Mice Exposed to Metallic Mercury Vapor Determined with NTA Complex
