Chromatographic Separation of Isomers of Tribenzylgermanium Nitrile Derivatives using Chemically Bonded Aryl Stationary Phases

Abstract

The present work concerns the development and optimisation of an HPLC method with UV detection in order to separate new organogermanium compounds (3‐tribenzylgermanyl‐butyronitrile and 4‐tribenzylgermanyl‐butyronitrile). Organic germanium compounds have found application as pharmaceutical drugs, as biostimulators in agriculture, and in the electronic industry. Three types of stationary phase: octyl, octadecyl, and aryl chemically bonded phases have been investigated. The octadecyl phase is the standard phase in most HPLC methods. Also, detailed analysis of the influence of the mobile phase has been carried out. Preliminary experiments have shown that regardless of the mobile phase composition, octyl and octadecyl stationary phases are not suitable for efficient separation. The use of an aryl chemically bonded stationary phase provided the best resolution of isomers. The greatest separation ratio (1.64) has been achieved for acetonitrile/water mixture (70/30) as the mobile phase.

Keywords:

• Organogermanium compounds
• Stationary phases: octyl
• octadecyl
• and aryl
• Chromatography
• π–π Interactions