Microscale: mass and volume measurements

One of the first aspects to be solved is the availability of electronic balances that allow weighing quantities within the required range. For weighing solids, the micro-spatula and weighing boats of the appropriate size for the order of magnitude of the substances employed.

As for the measurement of volumes, pipettes (drain-out or blow-out), automatic pipettes with disposable tips (Hamilton pipettes) and syringes (disposable or not) can be used, depending on the precision to be achieved.

For measurements of liquids where high precision is not required, e.g. washing a solid with a solvent or liquid-liquid extractions, a pre-calibrated disposable Pasteur pipette can be used. To calibrate a Pasteur pipette, 0.5 g of deionized water is weighed into a suitably sized test tube and with the aid of a nipple connected to the Pasteur pipette all the water is suctioned; the level of the water reaching the 0.5 g of deionized water is marked with a glass marker. The operation is repeated, this time for 1 g of deionized water.

That way we will have the pipette calibrated to measure approx. 0.5 and 1 ml of another liquid. Factory graduated plastic pipettes can also be used.

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