**2.4 Conclusion**

Among the six different sample extraction methods, two precipitate-based methods (method B and method C) were not suitable for the low recovery of lysozyme. Both method A and method D obtained good recoveries of six food additives simultaneously, but the major problem of method A is the lower reproducibility and much more time cost than method D. SPE was a simple and rapid method for the extraction of six food additives. From the results of method D–F, Poly-Sery HLB cartridge was confirmed as the most appropriate material for its high recovery.
