Determination of optimal lithium concentration in fractions of blood in atomic absorption spectrophotometer

Abstract

Introduction and purpose: Lithium (Li+) is the lightest of alkali metals. Both lithium carbonate and lithium citrate are currently in therapeutic use in patients that suffer from mental diseases. In practice, serum lithium concentration level is screened to check out if patients really take the necessary dose determined by a physician. In very special circumstances, from time to time forensic medicine needs to know the lithium concentration in serum that is drawn from a dead body. But samples usually contain whole-blood components (hemolyzed, clot etc.), therefore, measurement is done in mixture of blood components instead of desired serum values. This study is designed to get an idea about the optimum measurements and results in such conditions. Materials and methods: Blood samples were drawn from 30 long-term patients (15 male, 15 female) under lithium therapy. Each sample was divided into four tubes to obtain serum, plasma, erythrocyte and whole blood. Lithium concentration of each sample was measured in atomic absorption spectrophotometer. Values obtained from measurements were compared according to SPSS version 11.5 1-way ANOVA. Results and conclusion: When the mean lithium concentrations of blood fractions and whole blood were determined, the highest lithium concentration belonged to the serum which was followed by plasma, whole blood and erythrocyte. The difference between fractions of blood and whole blood except plasma and serum from lithium concentration was found to be statistically significant (p < 0.001). As a result of this study, it can be concluded that while trying to draw serum samples from a dead body, the sampling procedure should be performed in the appropriate region of big vessel. If it is not possible to obtain serum, it is necessary to prepare the sample standards belonging to fractions of blood and hemolyzed whole blood.