The analysis of dietary supplements is far less regulated than pharmaceuticals, leading to potential quality issues. Considering their positive effect, many athletes consume supplements containing L-histidine and β-alanine. A new microfluidic method for the determination of L-histidine and β-alanine in dietary supplement formulations has been developed. For the first time, capacitively coupled contactless conductivity detection was employed for the microchip electrophoresis of amino acids in real samples. A linear relationship between detector response and concentration was observed in the range of 10-100 µmol L-1 for L-histidine (R2 = 0.9968) and β-alanine (R2 = 0.9954), while achieved limits of detection (3 × S/N ratio) were 4.2 µmol L-1 and 5.2 µmol L-1, respectively. The accuracy of the method was confirmed using recovery experiments as well as CE-UV-VIS and HPLC-UV-VIS techniques. The developed method allows unambiguous identification of amino acids in native form without chemical derivatization and with the possibility of simultaneous analysis of amino acids with metal cations.

• Klíčová slova
• l-Histidine, Amino acids, Capacitively coupled contactless conductivity detection, Dietary supplements, Microchip electrophoresis, β-Alanine,
• MeSH
• beta-alanin * analýza   chemie   MeSH
• elektrická vodivost * MeSH
• elektroforéza mikročipová * metody   MeSH
• histidin * analýza   chemie   MeSH
• limita detekce MeSH
• potravní doplňky * analýza   MeSH
• sklo chemie   MeSH
• technologie zelené chemie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-alanin * MeSH
• histidin * MeSH