CHROMABOND QuEChERS Mix I (50 mL) citrate extraction mix consisting of: - 4000 mg MgSO4 - 1000 mg NaCl - 500 mg Na2H citrate x 1.5 H2O - 1000 mg Na3 citrate x 2 H2O individually weighed and filled into 50 mL centrifuge tubes (PP) with screw cap (PE) pack of 50