Determination of erythrocyte porphyrins by reversed-phase high-performance liquid chromatography using capsule-type silica gels coated with silicone polymer.

A simple, rapid and reliable method is described for determining erythrocyte porphyrins using a new type of reversed-phase silica whose surface is coated with silicone polymer. After a single-step extraction of blood with N,N-dimethylformamide, zinc protoporphyrin IX and protoporphyrin IX were separately quantified in a single run in 5 min. The column life was so long that no alteration in elution profile or retention time was apparent after 1500 injections of samples. The method described would be useful for the screening of lead exposure or iron-deficiency anaemia, and also for the diagnosis of erythropoietic protoporphyria.