Comments on Azide and Mercuric salts as seawater preservatives, and alkenes in the gulf of Mexico

A homologous series of volatile low molecular weight 1-alkenes was found in the surface waters of the Gulf of Mexico. Previous workers in the Gulf and other tropical waters did not report these compounds but they had poisoned their samples at sea for analysis later. The efficacy of azide and mercuric salts to preserve a representative alkene, 1-heptene, and heptane was tested. Neither salt significantly prevented loss of the hydrocarbons from spiked seawater. The 1-alkenes are most likely the abiotic products of photochemical oxidation and fragmentation of n-alkanes.