Aplikace Analysis of Pesticide Residues in Apple by GC-MS using Agilent Bond Elut QuEChERS Kits for Pre-injection Cleanup Stáhnout Determination of Pesticides in Lemon Oil via Modified Agilent Bond Elut QuEChERS Mothod Stáhnout Pesticides Analysis Using the Agilent 5977A Series GC-MSD Stáhnout