Determination of Beeswax Hydrocarbons by Gas Chromatography with a Mass Detector (GC -MS ) Technique

Abstract

a b s t r a c t 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.

Efficiency of GC-MS method in detection of beeswax adulterated with paraffin

“…We also estimated the minimum percentage of paraffin that can be detected by GC-MS. Moreover, our earlier studies of the composition of beeswax hydrocarbons (Waś, Szczęsna, & Rybak-Chmielewska, 2014a, 2014b and the results presented here and previously (Waś, Szczęsna, & Rybak-Chmielewska, 2015) for different types of paraffin and beeswax-paraffin mixtures prepared in the laboratory, allowed us to establish criteria for detecting beeswax adulteration with paraffin. The addition of paraffin to beeswax resulted in the occurrence of alkanes containing over 35 atoms of carbon in the molecule, which were not detected in pure beeswax.…”

“…The quantitative analysis of n-alkanes was made using the internal standard method. The technique was previously described in more detail (Waś, Szczęsna, & Rybak-Chmielewska, 2014a). The gas chromatography -mass detector method has been validated for the determination of hydrocarbons in pure beeswax, and in paraffin as well as beeswax adulterated with paraffin.…”

“…The preparation procedure applied to all tested samples was as reported previously (Waś, Szczęsna, & Rybak-Chmielewska, 2014a). An amount of 0.05 ± 0.001 g from the sample, was dissolved in 7.5 mL of heptane.…”

“…For the total n-alkanes in paraffin and beeswax, the recovery was 98.7 and 100.5%, respectively. The limits of determination of the method defined for each alkane (C 20 H 42 -C 40 H 82 ) were from 0.005 to 0.05 g/100 g (Waś, Szczęsna, & Rybak-Chmielewska, 2014a. …”

“…The paraffin properties and compositions may differ depending on the intended purpose of the Detection of paraffin in beeswax by GC-MŚ paraffin (Szpyrka, 1999). The chromatographic techniques applied for the evaluation of beeswax quality (Tulloch & Hoffman, 1972;Tulloch, 1973;Serra Bonvehi, 1988;Jimenez et al, 2003Jimenez et al, , 2004Jimenez et al, , 2006Jimenez et al, , 2007Jimenez et al, , 2009Serra Bonvehi & Ornantes Bermejo, 2012;Waś, Szczęsna, & Rybak-Chmielewska, 2014a are more efficient. These techniques allow for the detection of smaller amounts of adulterant (e.g.…”