Determination of Organic Volatile Impurities in Herbal Formulations and Extracts

TLDR: In this article, a gas chromatographic method for the determination of methanol, ethanol and isopropyl alcohol at residual levels in herbal formulations and extracts was developed using a flame ionization detector and the separation was carried out on BP 624 column, with nitrogen as carrier gas in the split mode by direct injection method.

Abstract: Organic volatile impurities (OVIs), residual solvents in herbal formulations and extracts were monitored using gas chromatography (GC) with Flame Ionisation detector (FID). As per GMP, measuring residual solvents is mandatory. It is now possible to take advantage of GC equipment with faster temperature ramping capabilities, in combination with shorter capillary GC columns, to achieve considerable gain in efficiency and reduction in analysis time. In the present study Gas chromatographic method for the determination of methanol, ethanol and isopropyl alcohol at residual levels in herbal formulations and extracts was developed using a flame ionization detector and the separation was carried out on BP 624 column, using GC 17 A shimadzu, with nitrogen as carrier gas in the split mode by direct injection method. The retention time for standard methanol, ethanol and isopropyl alcohol was found to be 3.72, 5.26 and 6.28 min respectively. The linearity for methanol, ethanol and isopropyl alcohol (IPA) was found to be in the range of 10-400 μL mL -1 , 10 - 500μL mL -1 and 1 -240μL mL -1 respectively. The method was validated according to ICH guidelines. The method described is simple, sensitive, rugged, reliable and reproducible for the quantitation of methanol, ethanol and isopropyl levels from herbal formulations and extracts and their levels are found to be within the ICH limits.