Análise de saliva humana para determinação de Ca, K, Mg e Na por técnicas espectrométricas e correlações de seus níveis com condições fisiológicas do organismo

Abstract

Saliva is a biological fluid composed by several organic and inorganic compounds. Its rich composition, due to a complex formation process, allows saliva to be an important biological fluid for collecting information from the organism. Organic compounds in human saliva have been largely studied and the correlation of their levels with physiological conditions are well reported in literature but, concerning inorganic constituents, there are not as much studies as on organic. Furthermore, there are gaps in literature concerning studies that investigate saliva samples preparation in a systematic way, many times being found very complex and little discussed acid digestion procedures. In this context, the aim of the present project was to develop a method for direct analysis of human saliva to determine metals by F AAS and F AES. The developed method provided results equivalent to those obtained through the reference method, the acid digestion. Thereby, the developed method was applied in two case studies. The first one involved to determine the Ca, K, Mg and Na salivary composition from 109 individuals, aiming to investigate implications of these levels to six physiological conditions: sex, blood glucose disorder, osteoporosis, heart palpitation, decreased muscular mass and unintentional weight loss. It was verified that men showed tendency to higher K concentrations than women, elderly showed tendency to lower Ca, Na and K values, people without blood glucose disorder showed tendency to higher Ca concentrations, people with osteoporosis showed tendency to lower Ca concentrations, people with heart palpitation showed tendency to lower Na and Ca concentrations and higher Mg concentrations, people without alterations in muscular mass showed tendency to higher Na concentrations than people with decreased muscular mass and people with unintentional weight loss showed tendency to lower Na and Ca values. The second case study involved 30 samples from people submitted to hemodialysis. The samples were collected before and after hemodialysis procedure and the results for Ca, K, Mg and Na showed variations without a pattern, increasing and decreasing in different ways to each patient. Although a pattern have not been identified, the results indicated that the hemodialysis procedure interfered in the salivary mineral composition.