Multi‐element and multi‐site isotopic analysis of nicotine from tobacco leaves

Abstract

The carbon, nitrogen and hydrogen stable-isotope contents of nicotine extracted from tobacco leaves were determined by Isotope Ratio Mass Spectrometry (overall ^H, ^^C and^N contents) and by the SNIF-NMR method (site-specific deuterium content). In addition, nicotine was chemically degraded into nicotinic acid so that the intramolecular distribution of carbon and nitrogen isotopes could be studied. A prerequisite for reliable measurements is the use of experimental procedures free of isotopic fractionation. Therefore, it was ensured that isotopic integrity was maintained throughout extraction, purification and chemical degradation steps. The multi-element and multi-site information provided is tentatively interpreted in terms of biochemical isotopic effects on intramolecular distribution patterns and of the infiuence of environmental factors on nicotine isotopic parameters.

Nicotine, acetanilide and urea multi‐level 2H‐, 13C‐ and 15N‐abundance reference materials for continuous‐flow isotope ratio mass spectrometry

“…In contrast, acetanilide and urea are not suitable as stable isotope reference materials for hydrogen because they both contain isotopically exchangeable hydrogen atoms linked to nitrogen that continuously re‐equilibrate with H 2 O, including atmospheric moisture. 2 H‐enriched nicotine could not be obtained for spiking, but fortunately the two commercially available nicotines #1 and #5 differ naturally in δ 2 H by ∼117 ‰ (Table 2), presumably because they were derived from tobacco crops grown in separate geographic areas with contrasting meteoric water δ 2 H values 19…”

“…For GC‐IRMS, we describe the development of five nicotine reference materials with different δ 2 H, δ 13 C and δ 15 N values. Nicotine is of significant toxicological interest and its stable isotope ratios may serve as forensic indicators for the origin of tobacco 19. For EA‐IRMS, Qi et al 20.…”

Stable isotope characterization of olive oils: II‐deuterium distribution in fatty acids studied by nuclear magnetic resonance (SNIF‐NMR)

“…5). For the five regions of production, the climatic normals used in the correlation were the following: France A similar tendency is observed for (D/H) 3 and (D/H) 5 as a function of the elevation of the region of production: olive trees cultivated in the mountains give oils which are relatively depleted in deuterium. This behavior is somewhat similar to that discussed for nicotine extracted from tobacco leaves (5).…”

Site-specific isotope effects and origin inference

“…2). Taking as reference site 3 of the pyridine ring, the relative isotope ratios determined for positions 1 to 12 (order of decreasing chemical shift) have the following values for a sample from Thailand: [24]. This behaviour illustrates the existence of very strong deviations with respect to a statistical distribution of 2 H which would lead to values uniformly equal to unity.…”