[Highlander81]

Pyrene in soil samples was extracted by sonic extraction followed by analysis using HPLC. A stock solution of pyrene (50 l, 100 mg/L) in acetonitrile was spiked (added) in a clean soil (0.5 g) and was extracted with 10 ml hexane. A portion of the extract (10 l) was injected to HPLC and the concentration of the extract was determined to be 0.45 mg/L. Calculate the percentage recovery of the extraction.

Anyone able to help me with this?

[JGK]

The problem does not make sense, Did you really spike a 0.5 g sample with 50 l of a 100 mg/mL solution?

Check the text and correct please

[Highlander81]

Sorry, it is supose to be:

Pyrene in soil samples was extracted by sonic extraction followed by analysis using HPLC. A stock solution of pyrene (50 µl, 100 mg/L) in acetonitrile was spiked (added) in a clean soil (0.5 g) and was extracted with 10 ml hexane. A portion of the extract (10 µl) was injected to HPLC and the concentration of the extract was determined to be 0.45 mg/L. Calculate the percentage recovery of the extraction.

[JGK]

Sorry, it is supose to be:

Pyrene in soil samples was extracted by sonic extraction followed by analysis using HPLC. A stock solution of pyrene (50 µl, 100 mg/L) in acetonitrile was spiked (added) in a clean soil (0.5 g) and was extracted with 10 ml hexane. A portion of the extract (10 µl) was injected to HPLC and the concentration of the extract was determined to be 0.45 mg/L. Calculate the percentage recovery of the extraction.

Calculate the No. of milligrams Pyrene spiked in to the soil sample.

If all (100%) of this sample was extracted in 10 mL, what would the concentration be in mg/ml?

Convert that value to mg/L

What percentage of the above mg/L value is the actual value of 0.45 mg/mL?