Infrared Spectra of U.S. Automobile Original Finishes Post-1989. VIII: In Situ Identification of Bismuth Vanadate Using Extended Range FT-IR Spectroscopy, Raman Spectroscopy, and X-Ray Fluorescence Spectrometry

• NCJ Number: 246590
• Journal: Journal of Forensic Sciences Volume: 59 Issue: 2 Dated: March 2014 Pages: 344-363
• Author(s): Edward M. Suzuki Ph.D.
• Date Published: March 2014
• Length: 20 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

Chrome Yellow PbCrO4·xPbSO4 was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate BiVO4·nBi2MoO6, n = 0-2, which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability.

Abstract

Chrome Yellow PbCrO4·xPbSO4 was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate BiVO4·nBi2MoO6, n = 0-2, which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT-IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far-infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO4, and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these.