Zinc protoporphyrin (ZPP) can be used in the evaluation of anemia and lead poisoning.


Units for zinc protoporphyrin:

(1) µg/dL or µmol/L whole blood (assuming a hematocrit of 42% or 45%, depending on source)

(2) per dL or L packed red blood cells = (whole blood volume in dL) * (hematocrit)/ 100

(3) µg or µmole per mole heme

(4) µg per gram hemoglobin


Molecular weight of zinc protoporphyrin IX: 626.03


Conversion of µg/dL ZPP to µmol/L: 0.0160 (or 10/626.03)


Molecular weight of heme: 616.5


Conversion of heme in g/dL to mol/L: 0.01622

Conversion of heme in mg/dL to mol/L: 1.622 * 10^(-5)


Each molecule of hemoglobin has 4 heme molecules.

Molecular weight of hemoglobin: 64,500

Conversion factor hemoglobin g/dL to mol/L: 0.133


zinc protoporphyrine in µmol per mol heme =

= (zinc protoporphyrin in µmol/L) / (heme in mol/L)


zinc protoporphyrine in µmol per L packed RBCs=

= (zinc protoporphyrin in µmol/L whole blood) / (volume RBC in L per L whole blood)


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