Gas chromatographic determination of N-nitrosodialkanolamines in herbicide Di- or trialkanolamine formulations
Wigfield, Y.Y.; Lacroix, M.D.; Lanouette, M.; Gurprasad, N.P.
Journal - Association of Official Analytical Chemists 71(2): 328-333
1988
ISSN/ISBN: 0004-5756 PMID: 3384780 Document Number: 316583
A modified method is presented to determine trace quantities of N-nitrosodiethanolamine (NDEIA) and N-nitrosodiisopropanolamine (NDiPLA) in the triisopropanolamine (TiPLA) formulation of a mixture of picloram and 2,4-D. Isolated nitrosamines were converted to the corresponding trimethylsilyl (TMS) derivatives and determined by GC on DB1 column coupled with a thermal energy analyzer (GC-TEA). Eight samples of commerical TiPLA formulations were analyzed. Maximum detected levels of NDELA and NDiPLA were 0.6 and 0.9 p.p.m., resp., relative to total wt of a.i. Analysis of 13 samples of herbicide DELA formulation using a previously established method and a DB225 column gave NDELA results of 0.7-6.0 p.p.m. NDiPLA was not detected in those samples. Results were confirmed by GC-MS with oxygen negative chemical ionization detection. Detection limits for both nitrosamines were 0.05 or 0.07 ng (0.1 or 0.17 p.p.m.) for GC-TEA detection, depending on the analytical columns used, and 20 pg (0.04 p.p.m.) for GC-MS detection. Recoveries of NDELA were 87-109% for DEIA formulation spiked at 2.6 and 3.9 p.p.m., and 90-115% for TiPLA formulation spiked at 0.2-0.3 p.p.m. Similarly, recoveries of NDiPLA were 95.7-100% for the DELA formulation spiked at 0.24 and 0.48 p.p.m., and 82-118% for the TiPLA formulation spiked at 0.2-0.3 p.p.m.