The present invention relates to method for the direct detection and/or quantification of at least one compound with a molecular weight of at least 200, wherein the compound to be detected and/or quantified is a chemically complex molecule, wherein said chemically complex molecule is substituted with at least two groups —R, wherein each R group means independently —OH, —OP(O)(OH)2 or —P(O)(OH)2, with the proviso that at least two R are independently selected from —P(O)(OH)2 and —OP(O)(OH)2, wherein the compound or compounds to be detected and/or quantified are within a biological matrix, wherein said biological matrix is a biological fluid, a biological tissue, stomach contents, intestine contents, stool sample or a culture cells, wherein the method comprises performing a chromatography and identifying the retention time and/or the intensity of the signal by means of a mass or radioactivity detector.