Electrochemical determination of α-tocopherol using a poly (p-toluene sulfonic acid)-modified sensor in pharmaceutical preparations: a DFT-supported study
Microchemical Journal, cilt.227, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 227
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.microc.2026.118807
- Dergi Adı: Microchemical Journal
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Chimica, Index Islamicus, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Adsorption energy, DFT, Differential pulse voltammetry, Electropolymerization, P-toluene sulfonic acid, Vitamin E, Α-tocopherol
- İnönü Üniversitesi Adresli: Evet
Özet
Vitamin E is an important antioxidant that exists in eight different forms: four tocopherols and four tocotrienols. The most active and biologically effective form of the vitamin E family is α-tocopherol (α-TOH). Herein, the electrochemical determination of α-TOH was performed using a sensor (TSA/GCE) prepared by electropolymerizing of p-toluene sulfonic acid (TSA) on a glassy carbon electrode (GCE). A good linear relationship was observed in the concentration range 0.116–0.75 μmol/L for α-TOH, as analyzed by differential pulse voltammetry, yielding a limit of detection of 1.88 nmol/L. Pharmaceutical tablets were used as real samples to evaluate the method's accuracy and applicability. The accuracy and reliability of the tablet analysis were considered high, with recovery values ranging from 99% to 102%. The developed electrochemical method demonstrated high sensitivity and selectivity. In this study, the molecular interaction between TSA and α-TOH was investigated using density functional theory. The adsorption energy, calculated using total energy values, was found to be −27.13 kcal/mol (−113.52 kJ/mol). This energy level indicates that holding is energetically favorable and supports the theoretical binding of α-TOH to TSA.