These types of resin filled pipette tips have been around for a long time under different names. They have very specific uses (application) esp for samples with Mw < 50KD AND which are very, very low in concentration (e.g. femtomoles).

I have used them before when the sample volume/concentration was very limited for MS analysis. An alternative to other methods.

Some pros are:

• Great for tiny samples volumes which contain a semi-pure protein which need to be desalted before analysis. Normally we would use HPLC and a diverter valve to remove the salt or, if the sample volume is large enough, dialysis.
• Very little waste/loss.

A few drawbacks.

• It takes about 30 (or more) pipette operations per sample to process. There are lots of pre-equil and flush steps needed. Lots of them... your hands will be sore if you have lots of samples (automation is possible using multi-pipettes or well-plate versions).
• The media used in the pipette tip (e.g. C18, C4 or IE resin) may remove something you want! You may need to use another method (see above) to make sure you are "seeing" your actual sample.
• The resin capacity is super small because the sample concentration needs to be even smaller!