This standard specifies the gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) detection methods for morphine and monoacetylmorphine in the urine of drug addicts in forensic science. This standard is applicable to the qualitative and quantitative analysis of morphine and monoacetylmorphine in the urine or other urine of forensic drug suspects who have positive morphine preliminary screening tests.