|| 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 with appropriate 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. DO NOT THAW. 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.