I need to make a solution at 2000mg/kg.....?

Question

I need to make a solution at 2000mg/kg , I have a 100mg/100ul stock. How do I go about making a 2000mg/kg solution. the diluent used will be cyclohexane????? pls help

Answer 1

The density of cyclohexane is 0.78 meaning that 1 ml weighs 0.78 grams.  100 ul thus will weigh 0.078 grms.  The stock soln of 100mg/100ul is actually 100mg/0.078gms, or approx. 1282050mg/kg.

To make 2000mg/kg you will need to dilute the stock approx 6410 times.  So you could take 1 ul of stock and dilute to 6.41 mls.