Situations like the sand sample as described a couple of entries up can be a bit tedious to prepare for chemical cleaning process.
Typically they don't yield a great amount of material, and it tends to lie under a good deal of water after the washing of the sand to extract it.
Taking that water off can be a challenge. You have to remove it without disturbing the diatoms settled at the bottom. I have used 3ml pipettes, that is a long, slow process. So I tried a turkey baster. More volume is good, but the difficulty with it is that you have to hold the bulb under tension as you place it in the water and position it for the water draw. The slightest twitch in your hand during that process can cause a puff of water to exit the baster and disturb the settled diatoms - now you get to wait a couple of hours for them to resettle.
There had to be a better way, so I went looking. I came across this on Ebay
- Syringe Kit.jpg (134.3 KiB) Viewed 152878 times
It is a 100ml syringe with tubing. I reasoned that the syringe would be a lot easier to control than that darn rubber ball at the end of the turkey baster. The control should be pretty darn precise with nearly zero chance of an inadvertent puff escaping.
To make it work I needed a way to position the tube under the water's surface, but above the settled diatom material - a clamp of some kind would do the trick. I am sure there is probably a specialized mechanism precisely for this purpose, likely with a long German name, like a Hoppenhauffer Clamp or something like that. Not having a Hoppenhauffer clamp handy, I had to get creative. So here is what I came up with - first the construction shot
- Syringe Clamp Glue.jpg (154.59 KiB) Viewed 152878 times
Two spring clothes pins, glued perpendicular to each other.
Looks like this when in use
- Syringe Ready.jpg (153.73 KiB) Viewed 152878 times
One clamps to the vessel, the other clamps to the tube. You can place the tube a precisely the depth you want by just sliding it up or down in the jaws of the second clothes pin.
- Syringe Full.jpg (143.22 KiB) Viewed 152878 times
When the syringe is full you can easily release the tube for emptying.
A careful and slow draw on the syringe pulls the water out without disturbing the settled diatoms, and a 100ml per fill, you can move a lot of water in a hurry, especially compared to 3 ml at a time with a pipette.
The syringe was $12 shipped, the clothes pins were free from the neighbors clothes line.......Just kidding, we had them laying around.
Thought some of you might find this useful.
Rod