• Patient should not be smoking for four to six hours
• Walnuts, bananas, and α-methyldopa (Aldomet®) should be avoided for a week prior to sampling
• Other drug interference may occur, including epinephrine and epinephrine-like drugs (eg, nosedrops, sinus and cough preparations, bronchodilators, appetite suppressants)

Lavender (EDTA), 4mL x 2

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting

1. Spin
2. Transfer the plasma to Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as EDTA  plasma
3. Freeze at -20°C within one (1) hour of sample collection*

* The time between blood collection and the preparation of plasma is quite critical; if the time exceeds one hour, catecholamine values increase (when blood is kept at 4ºC) or decrease (when left at 20ºC).

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Dk green heparin (Li or Na), no gel

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting

1. Spin
2. Transfer the plasma to Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as the appropriate heparin plasma
3. Freeze at -20°C within one (1) hour of sample collection*

* The time between blood collection and the preparation of plasma is quite critical; if the time exceeds one hour, catecholamine values increase (when blood is kept at 4ºC) or decrease (when left at 20ºC).

Frozen (preferred) - 2 weeks

Ambient - 2 hours

• Specimen not drawn in correct tube
• Plasma not received frozen
• Thawed specimen
• Inadequate patient preparation

High-pressure liquid chromatography (HPLC) with electrochemical (EC) detection

Norepinephrine, plasma:
0 to 1 year: 0−659 pg/mL
1 to 18 years: 0−611 pg/mL
18 years and older: 0−874 pg/mL

Epinephrine, plasma:
0 to 1 year: 0−34 pg/mL
1 to 18 years: 0−80 pg/mL
18 years and older: 0−62 pg/mL

Dopamine, plasma:
0 to 1 year: 0−42 pg/mL
1 to 18 years: 0−32 pg/mL
18 years and older: 0−48 pg/mL

Plasma catecholamines are no longer used for diagnosis of pheochromocytoma.