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Dietary supplements used for improving brain function and strengthening attention are increasingly popular. However, illegal dietary supplements containing unapproved drugs continue to be seized. Therefore, it is necessary to rapidly screen and identify adulterated compounds in dietary supplements for public safety. To develop the simultaneous analytical method, we selected 11 nootropic compounds and optimized the simultaneous liquid chromatography‐electrospray ionization‐tandem mass spectrometry and optimal conditions for liquid chromatography‐quadrupole time‐of‐flight mass spectrometry were proposed to determine the fragmentation patterns of each compound. The specificity, linearity, limit of detection, limit of quantification, method detection limit, method quantitation limit, precision, accuracy, matrix effect, and stability of this method were evaluated according to international validation guidelines. The validated methods were applied to 54 samples containing dietary supplements and seized samples. On screening 11 nootropic compounds were detected in four solid samples (tablet and powder). By comparing the product ion ratios with the standards and quantification, vinpocetine (6.52–34.2 mg/g) was found in three samples, and omberacetam (995.6 mg/g) in one sample. To re‐confirm the detected compounds, the fragmentation patterns were compared with those of the standards using liquid chromatography‐quadrupole time‐of‐flight mass spectrometry. The developed simultaneous analysis method can help maintain public health and safety. [ABSTRACT FROM AUTHOR]

Natural-derived steroids and their analogues are present in various plants and insects. To minimize the chance of missing a positive doping test and avoiding potentially serious health problems, adequate screening methods are necessary for the detection of a wide range of natural-derived steroids and their analogues in dietary supplements. In this study, an accurate and simple liquid-chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine and quantify the natural-derived steroids and their analogues according to the International Conference on Harmonization of technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. The validation results indicating excellent extraction efficiency and low matrix effects show that the LC-MS/MS method is reliable for the detection of natural-derived steroids and their analogues. In addition, we established the ion fragmentation of turkesterone and ion fragmentation of four natural-derived steroids and their analogues. The validated method was applied to 60 dietary supplements purchased online and in person from international vendors in 2020. Ecdysterone and 5α-hydroxylaxogenin were detected respectively in 3 and 14 of 60 dietary supplements. Especially, a high amount of 5α-hydroxylaxogenin, an FDA-unapproved ingredient, was detected in two of dietary supplements (44.4 and 32.3 mg/g). This component should be controlled since it may cause unexpected side effects if administered excessively. Thus, this method will be helpful for the continuous control and supervision of unlicensed dietary supplements containing natural-derived steroids and their analogues. [ABSTRACT FROM AUTHOR]

Reports of the number of adulteration cases using illegal therapeutic substances in dietary supplements have increased. In recent years, various dietary supplements are being distributed that exaggerate the efficacy of treatment for prostate‐related diseases. To develop the preemptive monitoring method, we selected 21 prostate‐related therapeutic substances and optimized the simultaneous ultra‐performance liquid chromatography and liquid chromatography‐electrospray ionization‐tandem mass spectrometry and pretreatment procedures for various types of matrices including solid, liquid, and soft capsule samples. The methods were validated by determining the specificity, linearity, limit of detection, limit of quantification, method detection limit, method quantitation limit, precision, accuracy, recovery, stability, and matrix effect. The simultaneous methods were validated according to the international guidelines. In addition, using the validated methods, 81 real samples, which were searched and purchased by focusing on promotional phrases, such as prostate and prostatic hyperplasia, were successfully screened. As a result, sildenafil and tadalafil were detected in one seized capsule sample (5.15 and 14.6 mg/g, respectively). Synthetically, our approach could be useful for the determination of illegal therapeutic substances potentially adulterated in various types of dietary supplements. [ABSTRACT FROM AUTHOR]

Selective androgen receptor modulators (SARMs) are compounds with specific androgenic properties that have been investigated for the treatment of conditions such as muscle wasting disease. The reported androgenic properties have resulted in their use by athletes, and consequently they have been on the World Anti–Doping Agency prohibited list for more than a decade. To minimise the chance of an unattended positive doping test and to avoid potential serious health problems, adequate screening methods for the detection of a wide range of SARMs in these supplements is necessary. In this study, a rapid and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated simultaneously to screen and quantify six SARMs in dietary supplements, with confirmation by liquid chromatography-quadrupole-time of flight mass spectrometry (LC-Q-TOF/MS). The validated method was applied to 60 dietary supplements obtained by on-line and direct purchase from international vendors in 2020. Various SARMs were detected at high concentrations in 20 products which were advertised as having androgenic properties. For example, andarine was present at 7.2% in one product, and GW501516 was found at 3.49% in the another product. Furthermore, MK-677 and YK-11, not disclosed on the label, were detected in some products. YK-11 is easily hydrolysed in just a few hours. Although YK-11 is particularly unstable, such that the protonated ion [M + H]+ at m/z 431 for YK-11 was not detected, mass fragmentation, and a [M+ Na]+ ion at m/z 453.3 confirmed the presence of YK-11. Additionally, hydrolysed YK-11 under acidic conditions was confirmed by NMR spectral data, and 1H NMR and 13C NMR spectral data for YK-11 were in good agreement with literature data. This rapid and accurate LC-MS/MS method can therefore be successfully applied to screen and identify SARMs for the continuous control and supervision of dietary supplements. [ABSTRACT FROM AUTHOR]