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

2014 ◽  
Vol 58 (1) ◽  
pp. 145-157 ◽  
Author(s):  
Ewa Waś ◽  
Teresa Szczęsna ◽  
Helena Rybak-Chmielewska

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.

2001 ◽  
Vol 84 (3) ◽  
pp. 666-670 ◽  
Author(s):  
Roderick E Black ◽  
Fred J Hurley ◽  
Donald C Havery

Abstract Surveys of cosmetic raw materials and finished products for the presence of the carcinogen 1,4-dioxane have been conducted by the U.S. Food and Drug Administration since 1979. Analytical methods are described for the determination of 1,4-dioxane in ethoxylated cosmetic raw materials and cosmetic finished products. 1,4-Dioxane was isolated by azeotropic atmospheric distillation and determined by gas chromatography using n-butanol as an internal standard. A solid-phase extraction procedure based on a previously published method for the determination of 1,4-dioxane in cosmetic finished products was also used. 1,4-Dioxane was found in ethoxylated raw materials at levels up to 1410 ppm, and at levels up to 279 ppm in cosmetic finished products. Levels of 1,4-dioxane in excess of 85 ppm in children's shampoos indicate that continued monitoring of raw materials and finished products is warranted.


2015 ◽  
Vol 59 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Ewa Waś ◽  
Teresa Szczęsna ◽  
Helena Rybak-Chmielewska

Abstract To detect beeswax adulteration with hydrocarbons of alien origin (e.g. paraffin), gas chromatography with mass detector (GC-MS) technique was used. The method has been verified here on beeswax samples with different addition (3, 5, 10, 30, and 50%) of paraffin and validated under the conditions of repeatability and within - laboratory reproducibility. The addition of paraffin to beeswax can already be detected on the basis of an analysis of the chromatograms. The intensity of individual alkane peaks increased with the increase of the amount of paraffin added to the beeswax. This increase was the mostly visible for the alkanes with even numbers of carbon atoms in the molecule: C24H50, C26H54, C28H58, C30H62, C32H66, and C34H70. These observations have also been proven by quantitative analysis performed using the internal standard method. Adding paraffin to beeswax resulted in an increase in the total contents of n-alkanes as well as individual alkanes, and in particular, of the even-numbered alkanes. The addition of paraffin to beeswax also resulted in the appearance of alkanes containing over 35 carbon atoms in the molecule, which were not detected in beeswax. The method for determination of beeswax hydrocarbons with the GC-MS technique is characterised by satisfactory repeatability and within-laboratory reproducibility. This method can be used for the detection of beeswax adulteration with hydrocarbons of alien origin (e.g. paraffin).


2007 ◽  
Vol 72 (9) ◽  
pp. 1295-1305 ◽  
Author(s):  
Pavel Šimáček ◽  
Daniel Maxa ◽  
Gustav Šebor

This paper deals with the identification and determination of high-molecular-weight n-alkanes of petroleum origin using high-temperature gas chromatography (HTGC). Analysed samples, which were the concentrates of saturated hydrocarbons, differed in both the total content of n-alkanes and their distribution. They were analysed on various types of HTGC columns differing in length and inner diameter. While the determined total content of n-alkanes was comparable for all the chromatographic columns, differences were found in the efficiency of separation of n-alkanes over C40 as well as in their quantitative elution.


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