A practical procedure was developed for detecting nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) in household detergents by gas chromatography–mass spectrometry (GC–MS) with the introduction of a cleavage technique using aluminum iodide (AlI3) to convert NPEOs and OPEOs to their parent nonylphenol and octylphenol. The reliability of the cleavage process was evaluated using Igepal-210, Triton X-15, Tergitol NP-9, and Triton X-100 as substrates, demonstrating satisfactory efficiency. The effect of the sample matrix on the cleavage process was investigated, and the optimized dose of AlI3 was estimated. The major advantage of this method is the use of a common analytical tool (GC–MS) for accurate monitoring of APEOs after elimination of the ethoxylate chain, with detection limits of 12.5 mg/kg and 5.0 mg/kg for NPEO9 and OPEO9, respectively. Analytical results revealed that NPEOs and OPEOs were found in 12.6 % of 182 household detergents in the concentration range of 18–800 mg/kg.