Abstract: To address the issues of high costs and the inability to perform on-site rapid detection in conventional testing methods for aniline compounds in gasoline, a rapid detection method for the total content of aniline compounds in gasoline was established using the solid-phase ninhydrin colorimetric method.The test results show that the mixedstandard curve has a good linearity within the range of total mass concentration of aniline compounds in gasoline from 25 mg/L to 500 mg/L, with a linear correlation index of 0.9977 and a relative standard deviation of less than 10%. When this method was used to detect actual samples, the comparison with the detection results of gas chromatography-nitrogen chemiluminescence detection showed that the relative error was less than 15%. To avoid quantification deviations caused by abnormal fluctuations in the content of individual components in finished gasoline, the absorbance response factors of the reaction products between different aniline compounds and ninhydrin were used to calculate the theoretical equivalent content that should be obtained by ninhydrin colorimetric method. This was performed to verify the rationality of the calibration curve prepared using mixed standard samples. The results indicated that the relative error between the theoretical equivalent content and the value obtained from the ninhydrin colorimetric method standard curve was less than 5%. This method offers advantages such as short detection time, low consumption of organic reagents, portability of instruments, simple operation, and low cost, making it suitable for on-site rapid screening needs.

Key words: aniline compounds, gasoline, ninhydrin colorimetric method, on-site rapid detection, UV-Visspectrophotometry