Hello

1ppm means 1part/million (exp: 1mg/1000000mg) i.e. (1mg/kg).

But if you want to change the mass into volume i.e. tke kilograme to liter this is only with a liquide which its specific gravity is equal to 1 kg/liter ; here this liquid is distillate water at 1 atm and 4°C. so 1ppm is mg/liter of water at 4°C and 1 atm of pressure.

Good luck.

I am not disagreeing with Sellami but it is pretty routine to say that a liter of water weighs a kilogram somewhere near standard temperature and pressure which is 1 atm and 20 C or room temperature.

500 ppm evaporated extraction by weight then suspended in water or and solvent per liter depend on use of extract

ppm w/w, v/v , w/v, v/w

 thank you all for your answers!

Yes  i liter is 1000000 micro liter  500mg in 1000000 microliter  in other words 500 PPM (W/V)

Thank you Sr Murali