Scientists at White Sands Test Facility (WSTF) have devised a kit for extracting nitrosamines from aqueous solutions. In comparison with extractions according to the method recommended by the Environmental Protection Agency (EPA), extractions by use of the kit are faster, cheaper and less labor-intensive, and they yield greater recoveries as well as test results that are more accurate. No other nitrosamine test kit performs at the level of this kit while satisfying requirements unique to WSTF.
The nitrosamines found at WSTF are organic compounds. They are powerful carcinogens that are by-products of dimethyl hydrazine, a rocket fuel used at WSTF before the fuel was linked to human cancers. Because the EPA requires suspected groundwater and soil be tested for carcinogens by use of gas chromatography (GC) and because the EPA's method of extraction and preparation of samples for analysis by GC is a labor-intensive method that involves the use of dichloromethane, WSTF scientists developed their own extraction method, which involves the use of the present kit for sampling nitrosamines from aqueous solutions.
In developing the kit, the WSTF scientists improved on sampling kits that were already extant to provide for extraction and concentration of nitrosamines from groundwater or soil analysis into a nitrogen/phosphorous detector prior to GC. Their technique involves passing a sample with a volume of 250-mL through a solid-phase extraction tube that contains 0.5 g of activated charcoal. Experiments have shown that two nitrosamines found at WSTF - N-nitrosodimethylamine (NDMA) and N-nitrosodi-n-propylamine (NDPrA) - collected by this technique and stored in the dark at a temperature of 4 °C are stable for up to 28 days - sufficient time to ship samples for analysis. Once a sample has arrived in a laboratory, NDMA and NDPrA are eluted with 2 mL of acetone and analyzed under conditions detailed in EPA Method 607 and SW-846 Method 8070.
Nitrosamines in groundwater and/or soil can exert adverse effects on human health in production facilities where they are found, and contribute to overall pollution. Because some nitrosamines are powerful human carcinogens, their presence in any place where humans live or work must be of continuing concern to public and private industries. The WSTF sampling kit is expected to be most useful at WSTF, where its sensitivity and accuracy have significantly improved the ability of scientists to detect NDMA and NDPrA, which are two of the three on-site nitrosamines linked to dimethyl hydrazine. The kit could also be used in measuring the effects of production and/or pollution-abatement activities elsewhere, in connection with industrial activities that involve handling of the analytes of rocket fuels.
This work was done by Gary Moffett and Benjamin Greene of Allied Signal for Johnson Space Center. MSC-2279