Abstract: The present invention relates to a device consisting of a glass container, the inner walls of which have been modified after successive activation, silanisation and amidation reactions to house a porous crystalline coating. Said coating, which has the atomic sequence —Si—O—R-M-MOF, is covalently bonded to the inner wall of the container in an inverted radial manner, where R may be A) —Si—(CH2)3—NH—CH(?O)—(C6H4)—COO—; B) —Si—(CH2)n—NH—CH(?O)—(CH2)2—(C2HN3)—(CH2)n—(C6H4)—COO—; C) —Si—(CH2)n—O—CH2—CH(—OH)—CH2—NH—(CH2)n—(C6H4)—COO—; D) —Si—(CH2)n—S—(CH2)2—(CH2)n—(C6H4)—COO—, and M is a metal dependent on the type of MOF. The container can be used for the extraction and pre-concentration of analytes present in samples of different natures, from environmental to biological. The invention also relates to the use thereof for dosing medicines or for colouring or flavouring beverages.