10 mL (5 mL min.) aliquot of 24 hour Urine. Collect urine with 25 mL 50% concentrated HCl to maintain pH below 3. For children adjust the volume of acid according to the expected urinary output. Keep urine refrigerated during collection. Mix well before aliquoting. Record body weight & 24 hour urine volume on container and test request form. Ship refrigerated or frozen. Avoid vitamin C and citrus fruits 48 hours prior to specimen collection.
spectrophotometry
4 days
Avoid vitamin C and citrus fruits 48 hours prior to specimen collection.