Analysis and detection of dyes, whether in solutions or on substrates, are of the requirements in textile and coloration fields related to dyeing, printing, and coating, in addition to non-destructive testing. This research aimed to study the most effective chemical groups in dispersed dye red (C.I. 11338) structure. Different concentrations were prepared gravimetrically by calibrated and traceable weighing and volumetric tools. An accurate fixed volume of 25 micrograms of the studied solubilized dye was added quantitatively to the KBr disk as a fast technique in FTIR instead of using a liquid sample compartment. Linearity of the concentration with the peak intensity was used to validate FTIR spectrophotometer as a quantitative analysis method. Firstly, we detect the dye's most detectable function chemical groups and find the best linear correlation between the concentration and transmission intensities. The results revealed that the distinct chemical groups that can be used are: strong C=C bending at 748.28 cm^-1, medium C=C bending at 808.07 cm^-1, and O-H bending at 1411.71 cm^-1 which give linear correlations of 0.9927, 0.9906 and 0.9998 respectively for concentration ranged from 0.001 to 0.05 ppm (w/v), LOD also studied and reached to a very low concentration less than 0.0005 ppm; the uncertainty of concentration at 1411.71 cm^-1 was 0.02% with coverage factor 2 to give 95% confidence level. The result revealed the applicability of this technique in the quantitative analysis of dyes.