Automating Dilute and Shoot

Pixel Kicks

13th March 2014

Any analyst working with LC-MS or GC-MS will have noticed, how, over time, mass-specs keep getting more sensitive.

Extra MS sensitivity is often used to simplify the sample preparation part of a method, since this is often a significant source of errors and cost.

“Dilute and Shoot” is one attractive approach that can arise. You simply dilute the sample with an appropriate solvent (so that the concentrations of any problem matrix compounds are reduced), and then you inject the same volume as before, taking advantage in the improved sensitivity available on a new instrument.

Dilute and shoot is often described as being free of sample preparation, when in fact you still have some work to do:

  1. You have to dilute and mix every sample in the batch.
  2. You normally have to add internal standard to every sample and mix.

Although this is pretty simple on paper, if you have large batches of samples to analyze, this can still represent a lot of work on a daily basis.

It is pretty easy to set-up a GERSTEL MultiPurpose Sampler (MPS) to carry-out this work for you. This can happen with the MPS as a separate free-standing workstation serving multiple instruments (GC-MS and/or LC-MS).  Alternatively, you can use the MPS on-line to act as a sample preparation robot and autosampler all in one.

The good news is, in our experience, that you can make a very compelling cost-justification. The more samples you are running – the better the figures work out.

Dilute and shoot, although fine in theory, doesn’t always work out and in practice some samples will always need a bit more work, but dilutions and addition of standards tends to always be part of the process, so you always end up better off.

If you think this might work out for you, and would like to explore this idea further, please call us on +44 (0) 1223 279 210 or email and we can discuss your application in detail.