The problem of the lack of selectivity in analytical instruments, which affects the accuracy of meas-urements, is considered. The causes and possible solutions to this problem are analyzed, with an emphasis on the use of chromatographic detectors and the piezo quartz microweighting method. The paper presents new sorbents with hydrophilic functional layers containing amide, amino-, diol and zwitterionic groups of various structures. These sorbents were synthesized and used to separate polar compounds by hydrophilic chromatography. As a result of the study, trends in the influence of the structure of functional groups, the grafted layer, the used spacer and the fixed phase matrix on the chromatographic characteristics of the sorbent were revealed