A method for characterizing and/or determining a sample, the method comprising a) providing an array comprising at least two different and separate matrices, each matrix including - a ligand comprising an aromatic structure and 2-5 chelating heteroatoms, and - optionally a lanthanide ion, b) introducing one or more solutions to said matrices wherein at least one of said solutions comprises - said sample and - optionally a lanthanide ion; in proviso that either said matrices or at least one of said solutions comprise said lanthanide ion; c) allowing said one or more solutions to dissolve said matrices; d) detecting at a predetermined time point a signal derived from said lanthanide ion in solution; and e) characterizing and/or determining said sample by comparing said signal with i) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions in the absence of said sample; and/or ii) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions with corresponding sample; and/or iii) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions with known sample, wherein said ligand is selected from the group consisting of a compound of formula wherein Z is H or aryl, and X is selected from COOH and CH 2 N(CH 2 COOH) 2, and 1,10-phenantroline (phen), a compound of formula wherein A is OH or COOH, and X 1 and X 2 are independently selected from halogen, H, and SO 3 H, and a compound of formula wherein X 3 is selected from H, COOH and CONH 2, and X 4 is selected from COOH and CONH 2. a) providing an array comprising at least two different and separate matrices, each matrix including - a ligand comprising an aromatic structure and 2-5 chelating heteroatoms, and - optionally a lanthanide ion, - a ligand comprising an aromatic structure and 2-5 chelating heteroatoms, and - optionally a lanthanide ion, b) introducing one or more solutions to said matrices wherein at least one of said solutions comprises - said sample and - optionally a lanthanide ion; in proviso that either said matrices or at least one of said solutions comprise said lanthanide ion; - said sample and - optionally a lanthanide ion; in proviso that either said matrices or at least one of said solutions comprise said lanthanide ion; c) allowing said one or more solutions to dissolve said matrices; d) detecting at a predetermined time point a signal derived from said lanthanide ion in solution; and e) characterizing and/or determining said sample by comparing said signal with i) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions in the absence of said sample; and/or ii) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions with corresponding sample; and/or iii) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions with known sample, i) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions in the absence of said sample; and/or ii) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions with corresponding sample; and/or iii) at least one signal derived from said lanthanide ion in the presence of said dissolved matrices and one or more said solutions with known sample, wherein said ligand is selected from the group consisting of a compound of formula wherein Z is H or aryl, and X is selected from COOH and CH 2 N(CH 2 COOH) 2, and 1,10-phenantroline (phen), a compound of formula wherein A is OH or COOH, and X 1 and X 2 are independently selected from halogen, H, and SO 3 H, and a compound of formula wherein X 3 is selected from H, COOH and CONH 2, and X 4 is selected from COOH and CONH 2.