Application of stable isotopes in the measurement of steroid hormones using the LC-MS / MS system


Stable isotopes:

Isotopes are different atomic species of an element that have the same atomic number, so they have the same position in the periodic table of elements and have the same chemical properties, but the mass number of isotopes is different due to differences in the number of neutrons in its nucleus This difference in mass allows these isotopes to be generally identified and isolated using mass spectrometry. The isotopes used for this purpose are stable and mostly include carbon isotopes, hydrogen, oxygen, nitrogen and sulfur. All of these characteristics mentioned above have led to the use of stable isotopes for the study, identification, isolation, etc. in steroid assay methods by LC-MS / MS.

Stable isotopes are widely used in industry, medicine, nuclear science, geology, agriculture, pharmacy and scientific research. Applications of stable isotopes in life sciences include:

Biochemical analysis


Photosynthetic pathway

Food Network

Food cycle in vivo

Human birthplaces

Metabolic studies


Sports medicine and ... pointed out.

Stable isotope labelling uses the simple fact that isotopes behave the same chemically while having different masses. Thus, molecules labelled with stable isotopes have the same biochemical properties. Recent advances in mass spectrometry (MS) and nuclear magnetic resonance (NMR) technology have greatly improved metabolite analysis, and hundreds to thousands of metabolites are now measurable with unprecedented accuracy. Over the past decade, such analyses have been relatively common in most biological samples, but there is still a significant challenge: the interpretation of analytical data. Using stable isotopes is a solution to this challenge. For example, one of the metabolic barriers is that many of the signals detected by mass spectrometry are unique and do not match the data in scientific databases. Since metabolites are derived from a specific substance, stable isotopes are used to label this compound to be used to identify derived biological metabolites. In other words, compounds labelled with stable isotopes as The internal standard is used to identify and determine the concentration of mass spectrometry data.

According to the researches and experiments were done in the field of material analysis by LC-MS / MS method for quantitative and accurate measurement and high sensitivity of steroids, like fatty acids, it has been considered as an internal standard and the presence of In the field of stable isotopes in the field of production of labelled compounds for use as a standard indicates the development and progress of this issue.




Hormones are a group of substances that are produced and secreted to harmonize the bodies of different organisms. Despite their small amount, these substances have significant effects on living cells. "Chemical classes" are the name of a group of substances in which hormones fall into one of two categories. The other category is neurotransmitters that carry the message from the nerve cell. Unlike hormones, neurotransmitters are short-lived and do not enter the bloodstream.

The importance of hormones

All hormones do is send a message from some cells to a larger group of cells. This message is conveyed to create harmony in the living body. Coordination in living organisms that are single-celled or simple-bodied does not require complex mechanisms, but in organisms such as humans, which have both large and complex cells, complex structures are required.


Types of hormones


Most hormones fall into one of two groups: polypeptides and steroids, but there are four groups in total, and one of them is still debated among biologists about whether it is a hormone. These four groups are listed below.

Peptide hormones

Amine hormones

Steroid hormones

Prostanoid hormones

Steroid hormones


Steroid hormones are structurally derived from cholesterol and play an important role in a range of physiological processes, including carbohydrate metabolism, fat and protein metabolism, as well as in neurological reactions. Steroid hormones are transported through the bloodstream to the cells of various organs and affect the physiological activities of the organs. They are transported through the bloodstream to the cells of various target organs and are known physiologically and clinically as regulators of various biological reactions. In other words, their main role is to coordinate physiological and behavioural responses. These hormones play an important role in the proper functioning of the body by controlling metabolism, neuronal transmission, and internal cell signals. In addition, steroids not only relieve seizures and prevent seizures, but also are effective in treating cancer. Therefore, the quantification of steroids in biological samples is an important tool in clinical research.

The main types of steroid hormones include estrogens, endogens and progesterone. Steroid hormone measurements are widely used in clinical research, general health assessment, and patient care. . Hormone testing is essential to diagnose certain diseases, such as adrenogenital syndrome, Cushing's syndrome, Addison's disease, hyperaldosteronism, and tumours. Steroid hormones are measured in various matrices including serum, plasma and urine.

Steroid kits:


Steroid kits, depending on their type, allow the quantification of 10-15 different steroids in serum, plasma and saliva using the LC-MS / MS system and include the most important clinical parameters.

The use of internal standards with stable isotope labelling for each of the analytes ensures the safe and reliable results of steroids.


Liquid Chromatograph - Sequential Mass Spectrometer or LC-MS / MS


Liquid Chromatograph Analytical Device - Sequential Mass Spectrometer or LC-MS / MS is a combination of liquid chromatography separation power with sensitive mass analysis capability and selective mass spectrometry. This method, in which a mass spectrometer is connected to a second mass spectrometer, is used when ionization is not sufficient to achieve the desired sensitivity. LC-MS / MS analyzes in less time with greater accuracy and sensitivity Performs the sample and provides reliable and stable results.

Today, sequential mass spectrometers are used to quantitatively and qualitatively determine the components of many complex compounds in nature and industry. The most common bio-analytical method used today is the liquid-hot copper chromatography technique and is used in toxicological studies, doping and quantitative analysis of drugs in biological fluids. It is a diverse, strong and sensitive method and is almost Used for all small molecules. The LC-MS / MS mass spectrometer has grown significantly in clinical laboratories over the past 10-15 years.


Evaluation of steroid hormones with LC-MS / MS device


Many steroid hormones have the same molecular weight, so measuring steroid hormones by mass spectrometer offers different benefits. Due to the flexibility of the device, several different analytes can be measured in one run, which allows multiple analytes to be reported in a single sample. In addition, the use of mass spectrometers can support the wide range of dynamics commonly seen in steroid hormones. It, therefore, supports differences in the concentration range between the analytes.


"stable isotope", "Steroid kits" , "Steroid hormones"

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