Common Mistakes and Troubleshooting

A frequent source of batch-to-batch inconsistency is failure to standardise the particle size of the starting plant powder, since coarser or finer material...

A frequent source of batch-to-batch inconsistency is failure to standardise the particle size of the starting plant powder, since coarser or finer material presents markedly different surface area for solvent contact and can shift extraction efficiency substantially between otherwise identical protocols. Variable extraction yield between successive batches of the same species is more often attributable to seasonal or geographical variation in the source plant material than to any procedural error, and is best addressed by standardising against marker compound content rather than by raw yield alone. Where a column chromatography separation fails to resolve two closely related compounds, adjusting the mobile phase polarity gradient in smaller increments, or switching to a reversed-phase system, is generally more productive than simply repeating the identical protocol.