Powder Weighing Procedure

Weighing powders can lead to worker exposure, as many powders tend to build up static electric charge, causing them to become airborne and adhere to surfaces in the weighing zone. Typically, weighing is done to prepare a solution of specific concentration as part of a process. Weighing directly in a fume hood, while beneficial, is not the best option and in some cases the fume hood might not be suitable for your protection. Generally, it's better to buy ready-made solutions, like acrylamide or sodium dodecyl sulfate. In the absence of commercially available pre-made solutions, it is necessary to adhere the protocol.

1. Position the scales in proximity to a hood (preferably a biological hood), but not within it.
2. Employ a container equipped with a screw cap for solution preparation.
3. Reset the scales upon placing the empty container, cork included, onto them.
4. Within the hood, transfer powder from its original packaging to the container, sealing the cap afterwards.
5. Thoroughly clean both the tool and the workspace of any dispersed dust and replace gloves.
6. Weigh the container containing the added powder on the previously reset scales. Utilize this weight to calculate the required solvent amount for achieving the desired concentration. Additional solvent may be added if needed.
7. For volatile solvents, incorporation should occur within a chemical fume hood. For non-volatile solvents, use a biological hood.
8. When dealing with minimal solid content in the original packaging, adjust solvent addition based on the weight indicated on the packaging.