1 Answer

Things You'll Need
Solution density value (in grams per milliliter)
Calculator

Instructions
1
Divide your value of micrograms per liter (ug/L) by 1000. Because a liter (L) is equal to 1000 milliliters (mL), this calculation will give you the concentration value in units of micrograms per milliliter. For example, if your solution is 250 ug/L, you would divide 250 by 1000 to get 0.250 ug/mL.

2
Divide the value you just obtained by the density of your solution in grams per milliliter. This will change the units again, this time to micrograms per gram (ug/g) of solution. In the case of the example, if the solution density was 1.08 grams per milliliter, you would perform the following calculation; 0.250/1.08 = 0.231 ug/g.

3
Rewrite the value you just obtained, keeping the same numerical value but using units of milligrams per kilogram (mg/kg). Because a milligram is equal to 1000 micrograms and a kilogram is equal to 1000 grams, this change in units does not change the actual value of the number because the ratio of the units has not changed. You now have your solution concentration in units of milligrams per kilograms, which is the same as parts per million. In the example, you would rewrite 0.231 ug/g as 0.231 mg/kg, which equals 0.231 ppm.

Read more: How to Convert Ug/L to PPM | eHow.com http://www.ehow.com/how_8505583_convert-ugl-ppm.html#ixzz2M7asf0lY