2 mL (1 mL min.) Plasma from 1 Lavender Top EDTA tube AND 50 mL (10 mL min.) aliquot of 24-hour Urine. Collect urine withappropriate volume of 50% HCl to maintain pH between 1–2. Do not use concentrated HCl. Record 24 hour volume on test request form and urine container. Ship frozen. Patient should strictly avoid Alpha-one blockers, Aminophylline, Amphetamines, Ampicillin, Beta-blockers, Ephedrine, Imipramine, Methyldopa, Buspiron, Codeine, L-Dopa, MAO inhibitors, Nicotine, Phenacetin, Phenothiazine, Theophylline, Vasodilators, Aspirin,PAS, Alpha-two agonists, Bromocriptine, Calcium channel blockers (long term use), Clofibrate, Propranolol, Penicillin, Reserpine, Thyroxine, Alpha-methyldopa, Isoproterenol, Labetalol, Mandelamine, Paracetamol, Cimetidine, Metoclopramide, vigorous exercise, alcoholic beverages, tea/coffee, tobacco, chocolate, pepper, vanilla & banana at least 72 hours before and during specimen collection.