Phenformin was prohibited by the ROC Department of Health in 1978. In this investigation, a GC-MS was used for the detection of phenformin in herbal preparation produced in Mainland China followed by determination by HPLC. For GC-MS, a HP-5MS capillary column was used. The initial column temperature was at 100°C for 2 min, ramping 10°C/min to 280°C, then holding at 280°C for 15 min. Ionization source temperature was at 230°C, and 70 eV electron impact mode was employed. HPLC was performed on a Cosmosil 5C18 AR (5 cm × 4.6 mm), and a μBondpak phenyl (30 cm × 3.9 mm) column using 0.01M potassium dihydrogenphosphate (pH 6.55) - acetonitrile (60:40, v/v) as eluent, with flow rate at 1.0 mL/min and detection wavelength set at 235 nm. Metformin was used as the internal standard. The interday and intraday precisions were less than 1.6%. The limit of detection and the limit of quantitation were 0.065 μg/mL and 0.20 μg/mL, respectively. The spike recovery was 102.7%. The average content of phenformin in the preparation was 3.45 mg per capsule.
Lin, M.-C.; Lin, J.-H.; and Wen, K.-C.
"Detection and determination of phenformin in Chinese medicinal capsules by GC-MS and HPLC,"
Journal of Food and Drug Analysis: Vol. 9
, Article 9.
Available at: https://doi.org/10.38212/2224-6614.2793