A large variation in an ion count between upstream and downstream spectra may not be significant if the magnitude of variation is equal within and between the downstream and upstream populations; changes in the abundance of this ion reflect only the intrinsic chemical variability of the environment and are not a relevant marker of the impact of the plant.
← all excerpts
SPIX: A new software package to reveal chemical reactions at trace amounts in very complex mixtures from high-resolution mass spectra dataset.
2
—
—
The sentences
On the other hand, a slight change in the abundance of an ion between “upstream and downstream spectra” may be significant if the abundance is almost constant within each population; it then reflects a real effect of the plant on water quality.