The intensities of each mass in the mass spectra were analyzed in Excel to determine if there were statistically significant differences between brands for each mass unit (see Figure ), using a two-tailed heteroscedastic t-test at 95% confidence. Over the 30-300 Da mass range, 183 masses were found to show a statistically significant difference between Jack Daniels' Distillery whiskies (Gentleman Jack and Jack Daniels) and Glenfiddich whiskies, of which 24 masses presented a significant difference between all five sample sets in positive ionization mode and unaltered pH. Similarly, at pH 7, 200 masses had a significant difference between Jack Daniels' Distillery whiskies and Glenfiddich whiskies, however, none of these were statistically significant between all five sample sets. At pH 10, there are 162 masses with a significant difference between Jack Daniels' Distillery whiskies and Glenfiddich whiskies, of which 16 had a statistically significant difference between all five sample sets. These are all good indications that principal component analysis (PCA) may be used to generate a classification model, and even in cases where a mass presents only slight statistically significant differences between classes, there may be adjacent features with differing covariances between brands/years due to varying isotopic enrichment.