Abstract
Here we describe a method of hydrocarbon (alkanes, alkenes, dienes) identification and quantitative determination of linear saturated hydrocarbons (n-alkanes) in beeswax using gas chromatography with a mass detector technique (GC -MS ). Beeswax hydrocarbons were isolated using a solid-phase extraction (SPE ) technique with neutral aluminum oxide (Alumina - N, 1000 mg, 6 mL), then were separated on a non-polar gas chromatography column ZB-5HT INFERNO (20 m×0.18 mm×0.18 μm). Qquantitative analysis of n-alkanes was conducted by the method of internal standard with squalane used as the internal standard. The basic parameters of validation (linearity and working range, limit of determination, repeatability and reproducibility, recovery) were determined. For all of the identified compounds, satisfactory (≥0.997) coefficients of correlation in the working ranges of the method (from 0.005 to 5.0 g/100 g) were obtained. The elaborated method was characterized by satisfactory repeatability and within-laboratory reproducibility. The average coefficients of variation for the total n-alkanes did not exceed 2% under conditions of repeatability or 4% under conditions of reproducibility. The recovery for individual n-alkanes was above 94%; for their total content, it was 100.5%. In beeswax originating from Apis mellifera, n-alkanes containing from 20 to 35 carbon atoms in their molecules were determined. The total content of these alkanes was between 9.08 g and 10.86 g/100 g (on average, 9.81 g/100 g). Additionally, apart from the saturated hydrocarbons, unsaturated hydrocarbons and dienes were identified.
Determination of n-Alkanes in Mixtures of Saturated Hydrocarbons by Means of Gas Chromatography