If you have only 1,0 mg of your amino acid you can make up ((1/molecular mass of amino acid) x 100) millilitres of a 10mM solution.

For example: 1mg glycine in 1.333 ml water or 1mg tyrosine in 0.552 ml water.

This is true for all the amino acids, but if you want to make up mixtures it will be a bit more complicated

Dear Prof.

Thanks for your answer

Simply use the following online calculator -

http://www.molbiol.ru/eng/scripts/01_04.html

Enjoy

Thank you Sir, this site is very useful

millimole= wt(mg)/Mr  (where, Mr= Molecular mass of amino acid)

Conc. in millimoles dm^-3 = (wt(mg)/(Mr*vol in ml))*1000

In your case Conc. in millimoles dm^-3 = 10, Hence,

10= (wt(mg)/(Mr*vol in ml))*1000 --> vol. in ml =( wt(mg)/(Mr*10))*1000 = wt(mg)*100/Mr . So add wt*100/Mr ml of solvent to the amino acid. 

Thanks you Sir for your help

you are welcome sir.