[Dwade]

I am preforming total N analysis using oxidation with an alkaline persulfate mixture. For quality control I spike deionized water (DI) and unknown samples with urea to compare % recovery. If my recovery in the sample is less than that of spiked DI do I multiply by the difference to obtain the actual TN concentration of the unknown sample?

Thanks.

[JGK]

Example: If your spike data indicates that your recovery is 91%

The the sample concentration (adjusted for recovery) would be:

= measured sample value/ (91/100) or measured sample value/ 0.91