[jgomez9]

I have to make a 10ppm solution from a 40% active material solution in 30mL, and I am having difficulty with it. I know that I can set it as a relation such as 10/x=40/100, but I believe that I am making mistakes with the conversions. Example: 10ppm = 10mg/L. My solutions are either way to high, or way to low. Thank you in advance for your help.

[sjb]

I have to make a 10ppm solution from a 40% active material solution in 30mL, and I am having difficulty with it. I know that I can set it as a relation such as 10/x=40/100, but I believe that I am making mistakes with the conversions. Example: 10ppm = 10mg/L. My solutions are either way to high, or way to low. Thank you in advance for your help.

What does 40% mean? What does ppm mean?

[jgomez9]

Thank you for replying.
The substrate that I am trying to work with is a solution of DTPA

I know ppm= 10 mg DTPA/L solution, and 40% = 40g DTPA/100g solution or 40mg DTPA/100mg solution
I can set up a relation solving for x that looks like this:

10mg DTPA/x L solution = 40g DTPA/ 100g solution

(this is where I believe my mistakes keep occurring because I need to convert the 100g solution to L. I know I also need to convert 40g DTPA to 40000mg DTPA, but thats easy).
I appreciate your help. I know I am just missing one little thing.