This guide provides detailed instructions for patients collecting a 24-hour urine sample for catecholamine testing at Tan Tock Seng Hospital. It explains important dietary restrictions including avoiding caffeine, foods with amines (bananas, cheese, wine), vanilla products, and citrus fruits for 2-3 days before and during collection. The material provides step-by-step collection procedures, proper storage instructions, and safety warnings about the preservative liquid to ensure accurate test results for this specialized hormone test.