Hello, fellow bioanalytical LC-MS chemists:

I am new to quantitative bioanalytical chemistry. As far as I know, there are mainly two types of sample preparations, namely well plates with robots and online injections. Could someone tell me the advantages and disadvantages of the both? Like costs, method development time, ease of use, LLOQ, method ruggedness etc. What do the majority of people use, well-plates or online (Turbulent flow or Spark Holland)?

TIA.

Janson

We have been using both methods. In my opinion, both types of methods work equally well. You will find some personal preferences with many users. In my opinion, off-line methods are very flexible, since you are not forced to make the final sample prep step to become compatible with your HPLC method. On-line methods, on the other hand, are less prone to small external variables which include operator errors etc. Since most of our methods run in rather small quatities, we do the offline methods manually, without robots.