Determination of manganese in biological materials by electrothermal atomic absorption spectrometry: a review.

The great diversity of methods for measuring manganese in biological materials (serum, plasma, whole blood, urine, spinal fluid, and hair) reflects the difficulty in measuring extremely small quantities of this element. Detailed examination of these methods demonstrates that the one most used is flameless atomic absorption spectrometry. In this review we report the different instrument settings for wavelength, slit width, protection gases, graphite furnaces, type of background correction, amounts measured, and thermal programs. We give detailed recommendations by various authors for collecting samples. A thorough description of the preliminary steps and the handling of the specimen samples is also included: direct determination with or without dilution, addition of a matrix modifier or determination after ashing, with or without chelation-extraction steps. The preparation of the standards, procedures used, analytical criteria (accuracy, precision, specificity, detection limit, linearity), problems (interferences, matrix effects), and reference values and their physiological variations are also described. We give a consensus of recommendations concerning the choice of a method.