Document Type

Thesis

Date of Degree Completion

Spring 2018

Degree Name

Master of Science (MS)

Department

Chemistry

Committee Chair

Dr. Anne Johansen

Second Committee Member

Dr. Carey Gazis

Third Committee Member

Dr. Dion Rivera

Abstract

The frequency and scope of wine fraud cases have increased worldwide, leaving wineries vulnerable to damage in reputation and potential lost revenue. In the United States of America, Washington State (WA) is the second-largest premium wine producer where wine fraud could have a significant impact on the industry. In an effort to reduce this risk, advanced analytical instrumentation and statistics were employed to chemically characterize, and thus geographically classify, 118 wines from 4 major wine producing regions located on 3 continents, including 64 wines from WA. Focus was on the analysis of inorganic and chemically stable tracers that are conserved and remain constant in bottled wine: 58 elements and 2 water isotopes, quantified with Inductively Coupled Plasma Mass Spectrometry (ICP-QQQ) and Cavity Ring-Down Spectroscopy, respectively. Linear discriminant analysis resulted in successful regional and continental classification, with 97.5% and 99.2% correct assignments, respectively. WA and California wines were significantly different from each other and from those collected in South America and Europe. The fourteen distinguishing parameters, in order of significance, were silicon, manganese, δD, rhenium, thallium, uranium, zinc, lead, sodium, rubidium, strontium, nickel, cerium and δ18O. Within WA, classification was low for the 7 regions, 6 of which are sub-appelations of one. This study is the first of its kind performed on US wines with particular focus on WA and represents a solid start for building a larger data base and model that could be used to discriminate between wines worldwide.

Available for download on Wednesday, June 28, 2023

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