# Please guide me : i have 0.5 grams of solid waste sample. It is acid digested and then diluted to 500 ml. This is tested for chromium by atomic absorption and the conc came out to be .243 mg/l. what will be the actual concentration in the solid sample?

By atomic absorption it is determined that the conc of chromium in 500 mL solution is $0.243 \text{ mg/L}$ .
So the mass of chromium present in 500mL or 0.5L solution will be $0.243 \frac{\text{mg}}{L} \times 0.5 L = 0.1215 m g$
And this amount of chromium has come from $0.5 g = 500 m g$ of solid waste sample.
=0.1215/500xx100%=0.0243%