Octyl-functionalized hybrid silica monolithic column was developed for in-tube solid-phase microextraction (SPME) to perform on-line preconcentration coupled to capillary high performance liquid chromatography (μHPLC) analysis.Hybrid silica monolithic column functionalized with octyl groups was conveniently synthesized by a two-step acid/base-catalyzed hydrolysis/cocondensation of tetraethoxysilane (TEOS) and n-octyltriethoxysilane (C8-TEOS).The size of through-pores can be adjusted by changing the ratio of TEOS to C8-TEOS in the polymerization mixture.The inter-batch and intra-batch precision were between 1.3% and 7.3%, 1.3% and 8.0% respectively.