Today, there are many fundamentally different approaches to determining the ratio of chemical elements in a biological sample. The most commonly used methods are electrochemical, chromatographic, and spectrometric ones. Electrochemical methods are based on the study of the electrochemical properties of the sample. Conductometry does not involve electrode reaction of the sample, whereas potentiometry and voltammetry do. A variation of the latter is polarography, the most common of the electrochemical methods in bioinorganic chemistry studies. Electrochemical methods are suitable for determining the amount of a very limited list of chemical elements in a sample and are rather low productive. However, they are quite inexpensive. Chromatographic methods involve the separation of sample components between mobile and stationary phases. Ion chromatography is used to determine the concentration of chemical elements in a sample, utilizing conductometry to separate ions. Chromatography is effective for determining the amount of alkali and alkaline earth metals in a sample, but is of little use for other elements. In addition, chromatography is quite demanding on the quality of sample preparation, whereas the sample is completely mineralized during the study. Finally, there is still insufficient experience with chromatography to standardize the method in routine studies. The most accurate methods for determining the elemental composition of a biosample today are spectrometric methods based on the detection of the wavelength of electromagnetic quanta emitted or absorbed by the sample. Atomic absorption spectrometry, inductively coupled plasma or flame atomic emission spectrometry, inductively coupled plasma mass spectrometry, and radiometric methods, such as neutron activation analysis, are considered the most advanced methods. The X-ray fluorescence is usually cheaper but also accurate enough. The main disadvantages of these methods are their cost and high staff requirements. Molecular absorption spectrometry is rarer applied due to a relatively low accuracy; however, this method has its significant advantages compared to other more precise spectrometric methods: it is much cheaper, compact, and economical in terms of energy consumption; therefore, molecular absorption spectrometry options can be used in expeditionary research. Indirect methods are also used to evaluate the elemental status, determining the concentration of a specific marker of a certain chemical element’s metabolism. Such methods are of much greater clinical importance since they do not reflect the concentration of an element in any medium of the body, but the function of a certain system that depends on the status of this element in the organism. Unfortunately, the set of such highly specific markers is currently limited.