N-Nitrosodiethanolamine in tobacco: method validation and levels present in US tobacco products
N-Nitrosodiethanolamine (NDELA) is a non-volatile nitrosamine classified by the International Agency for Research on Cancer (IARC) as a group 2B carcinogen. It has been identified in both tobacco and tobacco smoke and is currently included on the United States Food and Drug Administration (FDA) list of Harmful and Potentially Harmful Constituents (HPHCs). NDELA is not a natural component of tobacco or tobacco smoke and its presence is due entirely to the pesticide MH-30 (Trademark of Chemtura Corp.), which consists of the diethanolamine salt of maleic hydrazide. The use of MH-30 was suspended in the early 1980s eliminating the pathway for the introduction of NDELA in tobacco.
The objective of this study was to validate an analytical method for NDELA in tobacco and evaluate levels present in various research products manufactured in the United States since the late 1960s together with commercially available products. This study is not meant to be an exhaustive analysis of all tobacco products on the US market, but rather a selective analysis of the various product types available.
NDELA was extracted from tobacco with water and partitioned into ethyl acetate with excess sodium sulfate. An aliquot of the ethyl acetate fraction was dried with sodium sulfate, derivatized with BSTFA and analyzed by gas chromatography using nitrogen chemiluminescence detection. Quantitation was performed using N-Butyl-N-(4-hydroxybutyl)nitrosamine as an internal standard.
Levels observed in the research products tested ranged from not detected to 3400 ng/g. NDELA was not detected in any of the commercial samples analyzed and this study suggests that this compound should be removed from the HPHCs list.