Figure 5.

Extracted ion chromatograms of representative carboxylic acids at specific light/heavy concentration ratios. Upper traces (a, b, c) are light-form derivatives; lower traces are heavy-form derivatives. Corresponding MS spectrum (a', b', c') of the pairs of light- and heavy-form derivatives are also shown. a, a': Malonic acid at ratio 8:1 (light/heavy); b, b': formic acid at ratio 2:1; c, c': benzoic acid at the ratio 1:1. Other experimental conditions are the same as in Figure 2.