Ronald J. Spanggord

Comparative mutagenicity of halogenated pyridines in the Salmonella typhimurium/mammalian microsome test

The Salmonella/microsome assay with strains TA97, TA98, TA100 and TA102 was used to examine the potential mutagenicity and structure-activity of 16 mono- and di-halogenated pyridines. The chemical reactivity of the halopyridines suggests that nucleophilic displacement of halogens can occur with halogens at positions 2, 4 and 6 being displaced in addition-elimination reactions. 2-Chloropyridine gave a positive result with rat-liver metabolic activation, and 2-fluoropyridine gave equivocal results under these conditions. Mutagenic responses were also obtained with 2-chloromethyl pyridine and 3-chloromethyl pyridine, in both the presence and absence of rat-liver S9. These results suggest that the halogenated pyridines, especially with halogens at the 2-position, and singly on a methyl substituent, have mutagenic activity in the Salmonella assay.

Development and application of an analytical method for the determination of squalene in formulations of anthrax vaccine adsorbed

Specific lots of Anthrax Vaccine Adsorbed, administered to members of the US Armed Forces, have been described on various Internet sites and in news articles as a source of squalene, a chemical purported by these media to be associated with the Gulf War Syndrome. We have developed and validated a method using high-performance liquid chromatography with ultraviolet detection for the determination of squalene in anthrax vaccine preparations. The method has a limit of detection of 140 parts per billion and has been successfully applied to a commercial vaccine known to contain squalene. We have applied this method to 17 lots of Anthrax Vaccine Adsorbed administered to members of the US Armed Forces. No squalene has been detected in any lot. The results of these analyses provide direct evidence for the absence of squalene as an ingredient or a manufacturing contaminant in Anthrax Vaccine Adsorbed.

Fate of diethylene glycol dinitrate in surface waters

Abstract The environmental fate of diethylene glycol dinitrate (DEGDN) in surface waters is dominated by photolysis with surface half-lives ranging from 15 days in summer to 59 days in winter at 40°N. The environmental quantum yield is 0.18. Photolysis of DEGDN initially forms nitrate ion and 2-hydroxyethyl nitratoacetate; the latter photolyzes further to 1- and 2-carbon acids and additional nitrate. DEGDN biotransforms with a second-order rate constant of 3.9 × 10−11 mL cell−1 h−1, corresponding to a half-life of about 2 years in a typical surface water. Intermediate biotransformation products were observed but were further transformed and did not accumulate. DEGDN is expected to move readily through soils because it had low soil sorption coefficients Kp of 2 and 0.8 g mL−1 on EPA-5 and EPA-18 sediments, respectively. Abiotic reduction occurred rapidly in lake and river sediments but the importance of this process for overall fate is difficult to quantitate. Other fate parameters measured at 25°C were a water solubility of 3900 mg L−1, octanol/water partition coefficient of 9.6 (dimensionless), Henrys constant of