Site-specific natural isotope

GC/isotope ratio MS and site-specific natural isotope fractionation deuterium NMR spectroscopy are useful more recent tools for detecting sophisticated adulterations [3-5]. [Pg.74]

Site-specific natural isotope fractionation (SNIP) NMR (SNIF-NMR) quantitative H-NMR measurements... [Pg.379]

More recently, enantiomer ratios have been used as evidence of adulteration in natural foods and essential oils. If the enantiomer distribution of achiral component of a natural food does not agree with that of a questionable sample, then adulteration can be suspected. Chiral GC analysis alone may not provide adequate evidence of adulteration, so it is often used in conjunction with other instrumental methods to completely authenticate the source of a natural food. These methods include isotope ratio mass spectrometry (IRMS), which determines an overall 13C/12C ratio (Mosandl, 1995), and site-specific natural isotope fractionation measured by nuclear magnetic resonance spectroscopy (SNIF-NMR), which determines a 2H/ H ratio at different sites in a molecule (Martin et al 1993), which have largely replaced more traditional analytical methods using GC, GC-MS, and HPLC. [Pg.1037]

SD standard deviation SDE simultaneous distillation extraction SDS sodium dodecyl sulfate SFC solid fat content SFI solid fat index SHAM salicylhydroxamic acid SIM selected ion monitoring SNIF-NMR site-specific natural isotope fractionation measured by nuclear magnetic resonance spectroscopy SP-HPLC straight-phase high-performance liquid chromatography... [Pg.1309]

A particular mention is needed for describing one analytical technique capable of detecting the exact site-specific isotope ratio. This technique, called SNIF-NMR (site specific natural isotope fractionating technique), constitutes the most specific and sophisticated method used for food authenticity determination. [Pg.92]

Cotte, J. F., Casabianca, H., Lheritier,J., Perrucchietti, C., Sanglar, C., Waton, FI., and Grenier-Laustalot, M. F. (2007). Study and validity of 13C stable carbon isotope ratio analysis by mass spectrometry and 2H site-specific natural isotopic fractionation by nuclear magnetic resonance isotopic measurements to characterize and control the authenticity of honey. Anal. Chim. Acta 582,125-136. [Pg.159]

The first paper dealing with the NMR determination of non-random distribution of deuterium appeared in 1981 and the site-specific natural isotope fractionation studied by nuclear magnetic resonance (SNIF-NMR) terminology was proposed.36 Since this time several review articles on application of deuterium and 13C NMR natural abundance spectroscopy were published.37 1... [Pg.153]

Due to the inability to reliably detect beet sugar additions, the site-specific natural isotope fractionation nuclear magnetic resonance (SNIF-NMR) method used widely in the wine industry was adapted for the maple industry (Martin et al., 1996). This method determines the site specific isotope concentrations of organic compounds by nuclear magnetic resonance of ethanol fermented from the suspect sample. [Pg.138]

The biosynthetic origins of vanillin can be determined by the analysis of naturally occurring isotope ratios (in practice, chiefly 2H/1H and 13C/12C), using isotope ratio-mass spectrometry (IR-MS) and nuclear magnetic resonance (site-specific natural isotope fractionation SNIF-NMR ). Isotopic ratio... [Pg.300]

Martin, G.J., Martin, M.L. and Zhang, B.-L. (1992) Site-specific natural isotope fractionation of hydrogen in plant products studied by nuclear magnetic resonance. Plant, Cell and Environment 1 5, 1 037-1 050. [Pg.310]

Site-specific measurement of isotope ratios can be made using site-specific natural isotope fractionation-nuclear magnetic resonance (SNIF-NMR). This was first proposed in 1981 by Martin and Martin [30], who then applied it to the adulteration of food (wine) in 1988 [31]. This technique allows D H ratios for specific H atoms within a molecule to be measured and can provide additional... [Pg.126]

An NMR spectrometer for SNIF-NMR (Fig. 6.17) (site-specific natural isotope fractionation NMR) measurements [226] must be specifically equipped and adapted, e.g. for deuterium analysis by a high field magnet (e.g. 9.4 T, corresponding to 400 MHz ( H) and 61.4 MHz ( H) resonance frequency, or 11.4 T, corresponding to 500 MHz ( H) and 76.8 MHz ( H) resonance frequency), a specifically adapted H-NMR probe with fluorine lock and proton decoupling, highly stable electronics and software for spectra acquisition and data processing/treatment. Instrumental details... [Pg.616]

G.J. Martin Deuterium-NMR in the investigation of site-specific natural isotope fractionation (SNIF-NMR) - Automation of wine NMR. Laboratoire de RMN et Reactivite Chimique Universite de Nantes - CNRS UA 472... [Pg.657]

G.J. Martin, M.L. Martin (1988) The site-specific natural isotope fractionation-NMR method applied to the study of wines. In H.F. Linskens, J.F. Jackson (eds.) Modern Methods of Plant Analysis, Vol. 6. Springer Verlag, Berlin, pp. 258-275... [Pg.657]

Site-specific natural isotope fractionation (SNIF) NMR, which determines different (D/H), isotope ratios from the NMR spectra, has been used to characterize essential oils derived from a variety of botanicals (lavender, spike lavender, bose de rose oil, bergamont, germanium, clary sage, petit grain, coriander, Formosan, and camphor oil) and geographical regions versus synthetically produced oils. These SNIF-NMR results combined with DA allowed the natural and synthetic oils to be unambiguously indentified. ... [Pg.66]

Over the years, Site-Specific Natural Isotope Fractionation (SNIF) NMR has been used extensively in food analysis. Deuterium ( H) is widely dispersed in the whole solar system and so it is as well on earth. Actually, the deuterium isotope ratio in water, usually expressed in parts per milhon (ppm - just... [Pg.231]

G. J. Martin, Deuterium-NMR in the Investigation of Site-Specific Natural Isotope Fractionation (SNIF-NMR), Technical brochure by Bruker Analytische Messtechnik GMBH, No. NMR/A314/188 (1988). [Pg.236]

The methods of authentication through the determination of stable isotope ratios have in recent years found a remarkably wider range of food applications. The combination of site-specific natural isotope fractionation (SNIF)-NMR with mass spectrometry methods has been the basis of the development of many applications mainly to wine, fruit juices, olive oil, and some other foods. [Pg.122]

H-NMR (Site Specific Natural isotope Fractionation Using NMR (SNiF-NMR))... [Pg.3353]

Due to the complexity of food matrices several advanced spectroscopic techniques have recently been successfully employed to solve authenticity problems, including near infrared spectroscopy (NIR), mid infrared spectroscopy (MIR), low- and high-field nuclear magnetic resonance (NMR), site-specific natural isotopic fiactionation (SNIF-NMR) and... [Pg.158]

Spectroscopic techniques used in essential oil analysis comprise ultraviolet and visible spectrophotometry, infrared spectrophotometry (IR), mass spectrometry (MS), and nuclear magnetic resonance spectroscopy (NMR), including the following H-NMR, C-NMR, and site-specific natural isotope fractionation NMR. Combined techniques (hyphenated techniques) employed in essential oil analysis are GC/MS, liquid chromatography/mass spectrometry, gas chromatography/Fourier transform infrared spectrophotometry (GC/FT-IR), GC/FT-IR/MS, GC/atomic emission detector, GC/isotope ratio mass spectrometry, multidimensional GC/MS. [Pg.393]

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