Distinguishing Amber and Copal Classes by Proton Magnetic Resonance Spectroscopy

Lambert, Joseph B.; Tsai, Charlie; Shah, M. C.; Hurtley, Anna E.; Santiago‐Blay, Jorge A.

doi:10.1111/j.1475-4754.2011.00625.x

Cited by 34 publications

(30 citation statements)

References 28 publications

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“…The 1H spectrum of sample 1750 was essentially identical, whereas sample 1751 was insufficiently soluble to provide a spectrum (a typical result for coal). The 1 H spectrum of sample 1749 ( Figure 9) also is typical of Group A ambers, as seen from comparison spectra (Figure 1, Lambert et al 2012). There are four important regions in 1 H spectra.…”

Section: Nuclear Magnetic Resonance Spectroscopy Experiments and Resultsmentioning

confidence: 69%

“…(4) The two-dimensional (2D) 1 H method known as COSY (COrrelation SpectroscopY), in which both Cartesian coordinates represent the frequency of 1 H resonances. Proton NMR spectra can provide distinctions sometimes not apparent from 13 C spectra (Lambert et al 2012). For 13 C NMR measurements (taken at 100 MHz), samples were ground into a fine powder and loaded into a Varian 5 mm general purpose Zirconia rotor sealed with Vespel caps.…”

Section: Methodsmentioning

confidence: 99%

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Late Cretaceous Amber in Texas: Chemical Characterization and Paleoenvironment

Friedman¹,

Lambert²,

Contreras³

et al. 2017

LEB

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Abstract:Amber is reported from a new locality in North Central Texas, USA. The amber clasts were found in thin carbonaceous horizons in the Woodbine Group. They exhibit a variety of colors including yellow, orange, red, brown and opaque white. No zooinclusions have been found, but some clasts present plant debris and inorganic inclusions. 13 C NMR, 1 H NMR, FTIR, and GC/MS analyses assign this amber to Group A or Class 1b and, as such, the botanical origin is considered to be a conifer. The low diversity palynomorph assemblage of the sediments is suggestive of a nearby source. The paleoenvironment is interpreted as non-marine, fluvial deltaic. Abundant charcoal fragments are noted. This observation is in concordance with the description of the Cretaceous period being a time of fires. Based on stratigraphic and palynologic data, the age of the amber is Early Cenomanian. This research represents the first study of amber in Texas.

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Section: Nuclear Magnetic Resonance Spectroscopy Experiments and Resultsmentioning

confidence: 69%

Section: Methodsmentioning

confidence: 99%

Late Cretaceous Amber in Texas: Chemical Characterization and Paleoenvironment

Friedman¹,

Lambert²,

Contreras³

et al. 2017

LEB

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“…There are two dominant peaks in the saturated region at δ 0.8 and 0.9. Additional peaks from saturated protons occur from δ 1.0 to 2.2 in a pattern this is repeated by almost all Group B ambers (Lambert et al 2012). In addition, there are two alkenic peaks at δ 5.3 and 5.5 and very weak aromatic peaks in the vicinity of δ 7.0.…”

Section: Discussionmentioning

confidence: 78%

Nuclear Magnetic Resonance Characterization of Indonesian Amber

Lambert¹,

Levy²,

Santiago‐Blay³

et al. 2013

Life: The Excitement of Biology

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Amber from four major Indonesian islands (Sumatra, Sulawesi, Borneo, New Guinea), Malaysian Borneo, and from the Papua New Guinea island of Vanatinai (a total of 19 samples) has been examined by solid state carbon-13 and solution proton nuclear magnetic resonance (NMR) spectroscopy. All samples but one had common NMR fingerprints by all spectral tests, characteristic of NMR Group B ambers. The single exception, called green copal, had NMR fingerprints very similar to a commercial sample of dammar, the name given to many modern exudates from Dipterocarpaceae trees in the region. There was a clear familial resemblance for the dammar and green copal samples with all the spectra from many samples of modern dipterocarp exudates, with the trend of greater spectral complexity in going from amber to copal/dammar and modern exudates. These spectral comparisons provide further evidence that dipterocarp forests provided the resins that matured into copal and eventually amber after the passage of millions of years.

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“…The carbonyl peak at δ 180, if present, usually survives. In the proton spectra (Figure 4), the three characteristic Group A saturated groupings (δ 0-3) are present (Lambert et al 2012), centered at δ 1.8 (broad with multiple peaks), 1.2 (narrow multiplet), and 1.6 (broad with two main peaks), although the middle grouping is more intense than the two broad groupings on either side. The peaks in the unsaturated region (δ 3.0-5.5) are weaker than other Group A counterparts.…”

Section: Gulf Coastal United Statesmentioning

confidence: 99%

Nuclear Magnetic Resonance (NMR) Examination of Fossilized, Semi-fossilized, and Modern Resins from the Caribbean Basin and Surrounding Regions

Lambert¹,

Santiago‐Blay²,

Ramos³

et al. 2015

LEB

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Amber, copal, and modern resins from the Caribbean Basin and surrounding regions have been characterized by carbon and proton nuclear magnetic resonance spectroscopy. Amber is characterized by broader spectra, in contrast to copal and modern resins, which have sharper spectra. Many alleged amber samples analyzed in the present study proved to be copal. Genuine amber raw materials from the Caribbean Basin have spectra that are broadly consistent with mine sources in Chiapas (Mexico), the Dominican Republic, and northwestern Venezuela. More particularly, amber artifacts from Puerto Rico have spectra that are more consistent with the Dominican spectra and artifacts from northern Colombia than with the Mexican and Venezuelan spectra.

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Distinguishing Amber and Copal Classes by Proton Magnetic Resonance Spectroscopy

Cited by 34 publications

References 28 publications

Late Cretaceous Amber in Texas: Chemical Characterization and Paleoenvironment

Late Cretaceous Amber in Texas: Chemical Characterization and Paleoenvironment

Nuclear Magnetic Resonance Characterization of Indonesian Amber

Nuclear Magnetic Resonance (NMR) Examination of Fossilized, Semi-fossilized, and Modern Resins from the Caribbean Basin and Surrounding Regions

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