Pre-weighed extraction sorbents for fast, simple sample prep for multiresidue pesticide analysis in a variety of sample matrices. Supports original unbuffered method. Contains 4g MgSO4, 1g NaCl in each slim, easy-open packet which fits perfectly into 50mL centrifuge tubes to prevent spills. Use 50 mL centrifuge tubes REST-25846 (50/pk) or EPPE-0030122179 for sample extraction. Replacement for REST-23992.