Determination of N-nitrosobis(2-hydroxypropyl)amine in environmental samples

Area of Science:

• Chemical carcinogenesis
• Toxicology
• Analytical chemistry

Background:

• N-Nitrosobis(2-hydroxypropyl)amine (ND2HPA) is a known carcinogen.
• Diisopropanolamine (Di-PA) and triisopropanolamine (Ti-PA) are industrial and cosmetic precursors.
• ND2HPA has been detected in commercial Di-PA and Ti-PA.

Purpose of the Study:

• To investigate the formation of ND2HPA from Ti-PA and nitrite.
• To quantify ND2HPA levels in commercial Di-PA and Ti-PA.
• To compare ND2HPA formation with N-nitrosodiethanolamine (NDELA) formation.

Main Methods:

• Gas chromatography-thermal energy analysis (GC-TEA).
• Gas chromatography-high-resolution mass spectrometry (GC-MS) with selected ion monitoring.
• Formation of tert-butyldimethylsilyl (t-BDMS) ethers for analysis.

Main Results:

• ND2HPA was found in commercial Ti-PA (21-270 ng/g) and Di-PA (20-1300 ng/g).
• ND2HPA formed from Ti-PA and nitrite at 37°C, pH 3.0, with a yield of 0.51% after 4 hours.
• NDELA formed from triethanolamine under similar conditions with a yield of 0.96%.

Conclusions:

• ND2HPA can be formed from readily available precursor amines under mild conditions.
• The presence of ND2HPA in commercial products warrants further investigation due to its carcinogenic potential.
• Sensitive analytical methods (GC-TEA, GC-MS) are suitable for ND2HPA and NDELA detection.