Application of Attenuated Total Reflectance Infrared Spectroscopy (ATR-FTIR) for Amber Identification and Research

Infrared spectral analysis is a commonly used means to research the characteristics of mineral material. Attenuated total internal reflectance infrared spectroscopy (ATR-FTIR) is widely used dues to its advantages such as rapidness, non-destructiveness and micro region detection. This paper focuses on different areas of amber, copal resin, coated amber to further study its ATR-FTIR through the BRUKER LUMOS independent type infrared microscope. The result shows: the two infrared absorption spectrum which are 1 643 cm(-1) due to stretching vibration of nu(C=C) and 889 cm(-1) due to deformation vibration of delta(arene C-H)are present in the amber originated in Dominica and Russia; the infrared absorption spectrum band lies at 1 300 similar to 925 cm(-1) due to stretching vibration of nu(C-O) has a certain instruction significance for the origin of amber; the three absorption spectrum of 3 080 cm-1 which is due to dis-symmetry stretching vibration of nu(as) (=CH2), 1 643 and 887 cm(-1) can be used as characteristic of copal resin and have identification significance; coated amber displays amber and artificial resin mixing infrared spectrum, which besides the characteristic infrared spectrum of amber, 760 and 702 cm(-1) infrared spectrum are caused by out-plane bending vibration of gamma(arene C-H) of resin. ATR-FTIR has important significance in the identification of cause, origin and enhancement varieties of amber.