Using Spikes and Recovery Samples

Now that the sample size and concentration of method development spikes are known (2.5 ng/mL in the present example), the concentrations of the analyte and SIS spiking solutions to be used in preparing cahbrators and QC samples can be calculated based on the volume of each solution to be added. If the analyst desires to use a spiking volume of 100 p.L, then a spiking solution prepared at 12.5 ng/mL would be required (remember that the sample volume in this example is 0.5 mL). 

As method development progresses, modifications to the method and chromatography wiU generally lead to higher recoveries and better sensitivity, resulting in improved signal baseline at the LLOQ. In many instances the size of the sample aliquot can be reduced to improve efficiencies and conserve sample. This approach has the added benefit of generating a more dilute extract, which 

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