​24 hr urine in 15 mL 50% HCl

Minimum aliquot volume : 30 mL urine

​High Performance Liquid Chromatography

​0 – 1 yr : < 10.7 µmol/mmol creatinine

2 – 4 yrs : < 6.3 µmol/mmol creatinine

5 – 9 yrs : < 4.7 µmol/mmol creatinine

10 – 19 yrs : < 4.7 µmol/mmol creatinine

≥ 20 yrs : 0 - 34.3 µmol/day

​Mean = 7 days, Range: 3 – 11 days

​Monday – Friday

​Instructions before sampling:

Patients should abstain from the following at least 3 days prior to and during urine specimen collection:
- intake of food like chocolates, coffee, tea, citrus fruits, and food containing vanilla and
- Where medically allowable, drugs such as aspirin, drugs containing gentisic and homogentisic acid, antihypertensive drugs, methyldopa, glyceryl trinitrate, chlorpromazine, L-Dopa, epinephrine, norepinephrine, prochlorperazine, reserpine, disulfiram, guanethidine, imipramine, MAO inhibitors, radiographic dyes (for IV pyelography)

Total 24-hour urine volume must be clearly indicated.