| Abstract: | N-Nitrosodimethylamine (NDMA) levels in samples of 600 g litre?1 aqueous dimethylamine (DMA) solution stored at 4, 25 and 40°C, in formulations of the DMA salt of 2, 4-dichlorophenoxyacetic acid (2, 4-D) and of the DMA salt of 4-chloro-2-methylphenoxyacetic acid (MCPA) at 40°C were monitored using a gas-liquid chromatograph coupled with a thermal energy analyser (g.l.c./t.e.a.). The NDMA content of aqueous DMA at 4°C increased from 0.32μgg?1 to 8.6μgg?1 in 156 days. At 25°C it increased from 0.20μgg?1 to 10.5 μgg?1 in 156 days and at 40°C from 0.76μgg?1 to 7.12μgg?1 in 54 h. At 40°C, the NDMA in the 2, 4-D/DMAsalt increased from 0–53μgg?1 to 2.79μgg?1 in 96 days and in the MCPA/DMA salt from 0.48μgg?1 to 5.51 μgg?1 in 21 days. |
