Trace Elements in Medicine (Moscow)
2021, 22(2): 59-65
METHOD FOR DETERMINING THE MASS FRACTION OF CALCIUM IN HAIR
E.V. Moiseeva, I.A. Potapova
FBSI «Nizhny Novgorod Research Institute of hygiene and occupational pathology» Rospotrebnadzor, Semashko str., 20, Nizhny Novgorod, 603950, Russia
ABSTRACT. Calcium is one of the most important macronutrients in the human organism. A change in its level can be the result of different metabolic disorders and some diseases, i.e. control of its content in the organism is a topical task. Hair analysis is the most optimal to decide this problem, because hair indicates cellular metabolism and minimizes the risk of infection during sampling. Hair has a fixed growth dynamics (0,3–0,5 mm/day), i.e. it contains a "record" not only about the present time, but also about the distant period. This allows controlling the level of elements in the organism, in particular calcium, throughout the treatment period. Currently, there are analytical methods for the determination of calcium in hair, but only atomic emission spectrometry and inductively coupled plasma mass spectrometry are approved. The purpose of this study is developing a method for measurement the mass fraction of calcium in hair using the method of atomic absorption spectroscopy (AAS). The selection of optimal conditions for the detection of calcium in hair by atomic absorption spectroscopy was made. Various temperature-time conditions of the sample's mineralization were studied. Optimal conditions for mineralization was 1 hour at 160 °C. The influence of the nitric acid's concentrations on the analytical signal was investigated. The decimolar solution was found to be less aggressive for the device. In addition, the effect of adding a lanthanum salt to the sample on the absorption signal was studied. The addition of lanthanum salt to the samples changed the repeatability, which was 4,1–5,2% instead of 15,5%–26,0%, respectively. The determined range of calcium concentrations in hair was 200–2000 μg / g with an error of 21%. The method is designed to detect calcium deficiency in different population groups.
KEYWORDS: calcium, hair, analysis, atomic absorption spectroscopy.Corresponding author: I.A. Potapova E-mail: PIA@nniigp.ru