QuEChERS extraction kit, TFDA method, buffered, 50/pk. Kit Contents: 4 g MgSO4, 1 g NaAcetate in 15 mL tubes. QuEChERS salts and buffers are prepackaged in anhydrous packages. This allows you to add them to the sample after the solvent, based on your method of analysis (AOAC or EN). Extraction kits include:;50 polypropylene centrifuge tubes (50 mL) with caps, MgSO4, NaCl, or other salts for buffering.;Extraction kits can also be purchased with ceramic homogenizers. These provide consistent grinding of the material being homogenized and can minimize variation. Kits featuring ceramic homogenizers are marked with a CH.