Include 24-hour total urine volume on the request form AND date and time collection started and finished. Note: If original container is received with pH >3, but <5, adjust pH to <3 with 6N Hall.
Instruct the patient to void at 8 AM and discard the specimen. Preservative must be added to the container prior to the start of collection. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (i.e., 8 AM the next morning). Label container. Keep collection on ice. Measure and record on the request form total urine volume. Remove 20 mL aliquot. pH should be less than 5.