The authors introduce a new technique to measure the methemoglobin in relationship to oxyhemoglobin, without interference of chemical reagents or enzymes. The methodical basis sets out to detect real values of methemoglobin in the blood. To determine the level of methemoglobin in relationship of oxyhemoglobin, the blood was hemolysed and the hemoglobins (metha and oxy) were stabilized in a phosphate buffer M/60 (or 60 mol L-1) pH 6.8. The levels of methemoglobin and oxyhemoglobin were obtained by spectrophotometric absorption at 630nm and 540nm. This technique was compared with the technique of Evelyn and Malloy, whose methodology measures the heme-structural subproducts of hemoglobin treated with potassium ferricyanide and cyanide solutions. This technique has the advantage of removing the interference of chemical reagents or enzymes without toxic risks. The values obtained with this standardization showed that the normal levels range between 1.9% and 3.8%.
Methemoglobin; biochemical measurement
