Chromatography Forum

My supervisor recommended not to weigh on plasticware, even for practical reasons, since this will lead to wrong measurement. No explanation was given to me.
Can any one explain the logic behind?

I wonder if he is concerned about the possibility of static electricity affecting the weighing? Weighing boats are made out of plastic although perhaps of a different type. Sorry this is not a conclusive answer. Perhaps it will lead to more discussion. PS Can you ask him why not? Sometimes our lab practices are based on the "we've always done it that way" or "that's the way I was taught" reasoning with no scientific validity.

You can buy anti-static plastic weigh boats; I've seen them in the VWR catalog.

I wonder if he is concerned about the possibility of static electricity affecting the weighing? Weighing boats are made out of plastic although perhaps of a different type. Sorry this is not a conclusive answer. Perhaps it will lead to more discussion. PS Can you ask him why not? .

Indeed, My supervisor argument with static electricity but he can't explain further and I myself don't understand how.

in our FDA laboratory, they do a lot of weighing for critical measurements.

I noted that they used several devices added to the balances to kill static . One is added to the right side door and is powered by external power supply.

Think they also used to have some type of radioactive bar to kill static electricity.

Don't know actual product names, maybe you could find some references on internet or call one of the major balance manufacturers.

Many of the samples often have static electrictiy on them which makes it difficult to handle them. So I don't know if they do it to increase accuracy of weighing or just to make it easier to manipulate the sample.

They normally weigh in the Cahn microbalance with little aluminum boats, tare first, place sample in boat, tap out sample into volumetric, remeasure boat, correct for amount not transferred.