Perfluorinated　compounds　(PFCs)　are　new　types　of　persistent　organic　pollutants　known　to　bioaccumulate　in　organism,　which　have　come　under　increased　scrutiny　due　to　the　close　relation　with　various　health　problems.　Sensitive　detection　of　PFCs　remains　a　significant　challenge　because　of　their　ultratrace　levels　in　complex　samples.　Herein,　fluorinated　magnetic　covalent　organic　frameworks　(Fe3O4@TpPa-F-4)　were　first　synthesized　via　a　monomer-mediated　in　situ　growth　strategy　and　served　as　fluorinated　magnetic　adsorbent.　Accordingly,　a　novel　pretreatment　method　based　on　fluorinated　magnetic　solid-phase　extraction　(FM-SPE)　combined　with　HPLC-MS/MS　was　developed　to　detect　ultratrace　PFCs　from　milk　samples.　The　as-prepared　Fe3O4@TpPa-F-4　possessed　regular　porosity　(0.81　nm)　with　large　surface　areas　(188.04　m(2)/g),　high　fluorine　content　(4.85%),　strong　magnetic　responsiveness　(50　emu/g),　and　good　chemical　and　thermal　stability,　which　rendered　it　an　ideal　adsorbent　material　for　highly　efficient　extraction　of　PFCs.　Under　the　optimized　parameters,　the　developed　method　displayed　good　linearity　for　six　PFCs　in　the　range　of　0.1-250　ng/L　with　high　correlation　coefficients　(r　=　0.9952),　and　the　corresponding　limits　of　detection　(LODs)　were　0.005-0.05　ng/L　(S/N　=　3).　Furthermore,　high　enrichment　factors　(EFs,　21.91-100.6　folds)　and　acceptable　relative　standard　deviations　(RSDs)　of　inter-day　(0.5-11.8%)　and　batch-to-batch　(2.3-11.7%)　for　the　six　PFCs　were　achieved.　Moreover,　this　method　was　further　employed　to　milk　samples　with　different　brands　and　packages,　in　which　ultratrace　PFCs　were　found　with　diverse　concentrations　from　10.36　to　729.34　ng/L,　confirming　the　promising　applicability　of　the　Fe3O4@TpPa-F-4　as　an　alternative　adsorbent　for　sample　pretreatment.　(C)　2019　Elsevier　B.V.　All　rights　reserved.