Powder dispenser - 24-well array (2026)

Updated version 2026.

Device designed to dispense powders (mainly inorganic bases) into 24-well multiwell plate arrays containing glass shell vials (8 mm diameter, 9 mm spacings). Bases are crushed with mortar and pestle and passed through a sieve if necessary, and then loaded onto the top plate 'reservoirs'. This effectively also loads the middle slide plate with powder and then just pushing the slide plate with the knob so it its contents drop into the vials below; a few taps on top is recommended to ensure everything falls through. Bring the knob back to reload the slide plate for the next dispense.

It seems that 'reservoirs' of some kind were needed to obtain better reproducibility and individual chamfered did better over column or full plate ones for some reason. Results are good enough for powders that don't need to be all that accurate; for example when looking at adding inorganic bases for cross-couplings. For the 25uL with NaHCO3, I got an average of 25.34 mg (SD = 0.59,