The invention discloses a method for detecting the residual quantity of halauxifen-methyl metabolites in cereals, and relates to the field of trace detection.The method comprises the following steps that S1, target metabolites in a cereal sample are extracted with an acidified
organic solvent, and a sample extracting solution is obtained; s2, taking supernate of the sample extracting solution, mixing the supernate with a compound purifying agent, and oscillating to obtain purified supernate; s3, enriching the purified liquid supernatant to obtain an enriched liquid to be detected; s4, reacting the to-be-detected liquid with a diazotization
reagent, and then reacting with a
coupling agent to generate an azo dye; and S5, determining the
absorbance value of the azo dye by using a visible spectrophotometric method, and calculating the residual quantity of the halauxifen-methyl
metabolite in the grains according to the
standard curve. Aiming at high-
humidity grains in rainy seasons, high-sensitivity and high-accuracy detection of trace residues can be realized under the condition that expensive
chromatography-
mass spectrometry equipment is not needed, so that an economic and reliable rapid screening means is provided for a
basic level.