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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Dwade on August 19, 2010, 12:21:42 PM

Title: % recovery for total N analysis
Post by: Dwade on August 19, 2010, 12:21:42 PM

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.

Title: Re: % recovery for total N analysis
Post by: JGK on August 19, 2010, 05:31:13 PM

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