Читать книгу Fundamentals of Analytical Toxicology - Robin Whelpton - Страница 45

It is easier to measure whole blood:plasma analyte distribution than to attempt to measure the erythrocyte:plasma distribution, a measurement that requires the preparation of washed erythrocytes. Analyte is added to a portion of analyte-free heparinized whole blood and, after allowing time for equilibration and controlling the pH (the pH of blood tends to fall in vitro), one portion of the blood is centrifuged to obtain plasma and a second portion is frozen and thawed to give haemolyzed whole blood. After measuring the analyte concentration in the plasma (C_P) and in the haemolyzed whole blood (C_B), the analyte erythrocyte concentration (C_E) can be calculated if the haematocrit, H, (the proportion of erythrocytes in the blood) is known:

(2.1)