Japanese Food Safety Notification (Shoku-An) No.0124001 (January 24, 2005, Ministry of Health, Labour and Welfare (MHLW)) announced the “Analytical Methods for Residual Compositional Substances of Agricultural Chemicals, Feed Additives and Veterinary Drugs in Food”, which includes “Chapter II Multiresidue Method, Multi-residue Method for Agricultural Chemicals by GC-MS (Animal and Fishery Products)”. Shoku-An No.1003001 (October 3, 2006) added the “Multi-residue Method for Agricultural Chemicals by LC-MS (Animal and Fishery Products)” and Shoku-An No.0226-2 (February 26, 2015) further added the “Multi-residue Method II for Agricultural Chemicals by LC-MS (Animal and Fishery Products).” In these comprehensive analytical methods, gel permeation chromatography (GPC clean-up) is employed during the purification process of test solution preparation. An overview of the test solution preparation method and the columns used for GPC clean-up are provided below. The extraction and purification steps vary depending on the type of sample.