SPE recovery greater than 100%?

I am evaluating a paper Gan et. al. 2013 (<https://doi.org/10.1016/j.chroma.2012.11.081>) Table S4 (see image below) and I am focusing on evaluating the percent recovery for using different solid-phase extraction (SPE) cartridges. Investigators were measuring different artificial sweetener concentrations in water samples. This table suggests that their sucralose (SUC) % recovery was 106% when they used 1 mM TRIS buffer and eluted with methanol and they used a Waters Oasis WAX SPE cartridge. I am assuming n = 3 means they did a sucralose measurement 3 times. **My ultimate question is, how can something have recovery greater than 100% after SPE?** Does the precision and error inflate this recovery value to be over 100?


[![enter image description here](https://i.stack.imgur.com/n454b.png)](https://i.stack.imgur.com/n454b.png)


