Inhibitory effect of alkyl groups on N-nitrosamine formation from secondary and tertiary alkylamines with monochloramine

N -nitrosamines are contaminants of emerging concern, and controlling these chemicals in potable water recycled for reuse has become important protecting public health. This study aimed to evaluate the influence alkyl chain lengths -nitrosamine precursors (secondary tertiary amines) on formation via chloramination. The molar conversion efficiency from dimethylamine, an -nitrosodimethylamine (NDMA) precursor, NDMA (0.67%) was greater than that diethylamine, -nitrosodiethylamine (NDEA) NDEA (0.38%). Similarly, trimethylamine (0.92%) triethylamine (0.33%). Interestingly, a considerable difference efficiencies were observed amines with , -dialkyl- α -arylamine structure: -dimethylbenzylamine -diethylbenzylamine 50.2% 1.7%, respectively. These results indicate ethyl groups have lower potentials producing corresponding those methyl groups. differences yields between can be explained by electron density nitrogen atom amine, which influences protonation amine stabilization intermediate species. findings could useful enhancing source control wastewater regulating runoff or industrial containing high concentrations specific precursors. • Formation four secondary tested. having group group. Benzylamines had higher values comparison simple alkylamines. Longer chains suppressed reactions.