Needle question. Drawing up - What am I doing wrong ?

[Achten]

I have searched but didn't come up with an answer.
I have skim-read the wiki but didn't come accross my problem. It's all about injecting liquids, my question is for drawing up the liquid in the needle.

I don't use my needles for injecting substances into my body, but only to measure very small amounts of certain liquids. (very concentrated cannabis fertilizers if you really want to know.)

I want to the pharmacy and bought 1ml insuline needles.

Anyway, whichwever method I use (drowning the "whole" needle in the liquid or only the fine/sharp point used for injection in the skin), the needles never draw up more than 0.1ml. The rest is just air.

I would understand if this was with some basic "play"-needles. But this is pharmacy-grade, right ? If people use this to draw up insuline don't they need a little accuracy ?

I can't really ask the pharmacist because she already gave me the weird look when buying them. Explaining what they're eally for would prove more of a hassle, IMO .

 

[pasha]

Since they're concentrated I would assume there are substances within this solution that cannot be drawn up with a regular syringe. If you want to measure your fertilizer with more accuracy, I would recommend going somewhere where they sell lab equipment.

 

[Jackeh]

If you want to measure the volume of something like this, buy a graduated cylinder. If you do buy a graduated cylinder, to ensure you lose none of your fertilizer due to it sticking to the sides, use a wash bottle (preferably deionised water) to rinse out remaining liquid.

If you want to be a little more accurate, buy a burette or a pipette instead.

NSFW:

Ignore the "acid and alkali" labels, I think that picture is from an acid-base titration.

Make sure to rinse out your equipment after every use and then let it dry, otherwise your measurements will be innaccurate.