Gilson that measures aliquots up to 1ml.

Up to, is there lower limit given?

And you didn't say what is Tyrodes concentration.

Tyrodes concentration is note given, what is important here is the concentration of atropine, Tyrodes is used to add up the volume so to change the concentration of atropine to the desired level. There is not given a lower limit for the Gilson, the idea is just that we have 3 measuring apparatus, 100ml,, 500ml, and 1ml.

What I think is to take 1ml of atropine 10^-3 and put it in the 100 volumetric flask and add up Tyrodes until full so that now we have a concentration of 10^-5. Then I have done some calculations but they are mixed up. The idea is that after this step should be another one to end up with 500ml Tyrodes solution (obviously in the 500ml flask) that contains 10^-8 atropine.

any ideas please...