Answer:
A better revision of this sentence would be:
What furnished a better understanding of the retention mechanism were the results of variation of the applied chromatographic conditions, such as the bulk solvent composition, the concentrations and ratio of the acid and base additives, the presence of water as mobile phase additive and the counter-ion concentration.
Explanation:
If you take a look at the revised sentence, you will see that the predicate (furnished) is much closer to the subject of the sentence (the results). If we place the predicate at the beginning of the sentence, we still retain the main meaning of the sentence, while making it closer to the subject of the sentence. You should always avoid making big gaps between the subject and predicate in a sentence.
