“…Cords were assessed by using established qualitative liquid chromatography tandem mass spectrometry methods designed to detect 49 drugs and their metabolites, including opioids, amphetamines, cocaine, benzodiazepines, barbiturates, gabapentin, phencyclidine, zolpidem, THC-COOH, and ethyl glucuronide (alcohol metabolite), as described in detail elsewhere. 10,19,20 Briefly, 1 g of umbilical cord tissue was homogenized in a master-mix solution containing sodium phosphate buffer, b-glucuronidase enzyme, and isotopically labeled internal standards. The homogenate was incubated at 55°C for 30 minutes for enzyme hydrolysis.…”