Goal. The choice of a chromatographic method and the development of a method for the analytical determination of imazethapyr, imazamox, imazapyr in herbicide preparative forms in the joint presence.
 Methods. Active substances were analyzed by thin layer chromatography. The linear range of the dependence of the area of chromatographic zones on the amount of active substance was assessed by a mathematical-statistical method.
 Results. Determination of pesticides by thin-layer chromatography includes the main stages: classification of pesticides by polarity; extraction of active substances from the analyzed sample; chromatographic separation, detection and quantification. The decisive factor in the analysis stages is the dipole moment (μ, D), which characterizes the polarity of the compounds. Imazethapyr, imazamox and imazapir are polar compounds (μ≥6, D) with the corresponding values: 6.1; 6.4 and 6.8 D. Extraction of active substances is carried out with ethanol. Qualitative determination — in a thin layer of adsorbent silica gel in the mobile phase: a mixture of ethanol with acetic acid in a ratio of 4 : 1.5. Identify compounds at the wavelength of the spectrum λ 254 nm and using the developing reagent silver ammonia. The calibration dependence of the area of the chromatographic zone of the compound on its amount is linear in the detection range of 0.30—1.30 μg and is described by the regression equations for: imazethapyr S = 12.345 C + 0.7778, R2 = 0.99; imazapyr S = 9.3671 C + 1.081, R2 = 0.99; imazamox S = 7.6234 C + 1.4462, R2 = 0.98. The equation is used to quantify the active ingredients in the chromatogram.
 Conclusions. The use of the method of thin layer chromatography makes it possible to select selective conditions for the analysis of imazethapyr, imazamox, and imazapyr in the presence of herbicides in preparative forms. The developed technique is an express method of control and provides determination of active substances in the course of one analysis with high accuracy (relative error is less than 5% at n = 5, P = 0.95). The analytical support of the developed and patented method allows for analytical control of active substances of the imidazolinone class in the formulation of pesticides by analytical and toxicological laboratories, testing services without the use of expensive devices.