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Sevasti,

 From your message, I would assume that you are interested in augmenting 
and speeding up the manual weighing process and not developing an 
automated system.

If you are not at all interested in any kind of automated system, skip 
the next few paragraphs.


It has been a number of years since I have thought about automated 
powder dispensing.

Pharmaceutical companies with large compound libraries have looked into 
this technology and the results have been mixed.

A number of laboratory robotics companies looked at the problem, 
declared that would be easy, and then failed.

Of those that have succeeded my personal favorite was the Haystack 
System that had an automated dispenser called the Haywain.  It was 
developed by TTP Labtech Ltd., Cambridge, UK.

However such a system is designed to manage a collection of 100,000 or 
more potential pharmaceutical compounds and not the small collection of 
vials that you have.

Mettler has also introduced an automated weighing system that may fit 
your needs: 
https://www.environmental-expert.com/products/model-qx-series-fully-automated-gravimetric-sample-preparation-377295

Automated weighing generally falls into one of four categories.

1.  The sample bottle is held horizontally over the balance pan while 
vibrating.  The vibration stops after the desired weight is reached.

2.  A robot moves a spatula into the compound bottle, holds the spatula 
tip over the balance, and then vibrates.  As before, the vibration stops 
once the desired weight is reached.

3.  The cap is equipped with some sort of Archimdes screw that a robot 
can turn.

4.  Some automated weighing systems use a vacuum to aspirate and 
dispense the compound.

If you really want to pursue some type of automated system, then your 
best place to look for more information would be the The European 
Laboratory Research & Innovation Group (https://elrig.org/)

One of the reasons that so many automation companies have tried and 
failed to automate the weighing process is that drug discovery compounds 
are not all dry, free-flowing powders.  They clump, are static 
sensitive, form very hard crystals, or are sticky.


You will really need to experiment and try different things to learn 
what works best for your standards.

Best of Luck!

Kevin Olsen

Formerly the Robotocist for the Research Compound Bank, Wyeth 
Pharmaceuticals.


On 9/30/2019 10:35 AM, Sevasti Eleni Modestou wrote:
> Hi all,
>
>
> Does anyone have any experience with powder pipetting very small amounts (in the 100 microgram range, or smaller)?
>
>
> If so, I'd love to hear about the tools you're using.
>
>
> We weigh multiple batches of powder standards for daily runs on three GS-IRMSs, and it would be amazing if we could simplify/speed up the process.
>
>
> Cheers,
>
> Sevi
>
>
> ---
>
> Sevasti Modestou, PhD (she/her)
>
> Postdoctoral Researcher, Clumped Isotope Research Group
> Department of Earth Sciences
> University of Bergen
> PO Box 7803
> 5020 Bergen, Norway
>
> +47 55 583 529
>
> Bjerknes Centre for Climate Research
> Jahnebakken 5
> 5007 Bergen, Norway

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