Grasas y Aceites, Vol 67, No 2 (2016)

Determination of saturated aliphatic hydrocarbons in vegetable oils


https://doi.org/10.3989/gya.0627152

R. B. Gómez-Coca
Department of Characterization and Quality of Lipids, Instituto de la Grasa – CSIC-Campus of Universidad Pablo de Olavide, Spain

R. Cert
Department of Characterization and Quality of Lipids, Instituto de la Grasa – CSIC-Campus of Universidad Pablo de Olavide, Spain

M. C. Pérez-Camino
Department of Characterization and Quality of Lipids, Instituto de la Grasa – CSIC-Campus of Universidad Pablo de Olavide, Spain

W. Moreda
Department of Characterization and Quality of Lipids, Instituto de la Grasa – CSIC-Campus of Universidad Pablo de Olavide, Spain

Abstract


The aim of this work is to inform about the development of a simple and reliable off-line method for the determination of saturated hydrocarbons (SH) in vegetable oils. SH can be used as markers for fuel or for mineral oil contamination in edible oils and fats. The method consists of the isolation of the fraction by LC on deactivated silver-silica gel and subsequent on-column GC-FID analysis. This stationary phase was prepared avoiding any kind of activation. The method was developed and validated through the participation in both a proficiency test organized by the Joint Research Centre of the European Commission, and a collaborative trial carried out with trained Spanish laboratories according to the standard ISO 5725. Results showed acceptable repeatability and reproducibility values, and Horrat index, being this protocol in use with satisfactory results ever since. The method’s LOQ is 15 mg.kg–1 and its LOD 5 mg.kg–1, which make it suitable to quantify the 50 mg.kg–1 limit established by the EU, and to detect mineral oil content within the 10–500 mg.kg–1 range. Although other procedures with lower LOD have been developed throughout the years, the use of just regular laboratory equipment such as GC-FID makes the proposed method appropriate for application on a routine basis.

Keywords


Fuel-oil; Mineral oil; Saturated hydrocarbons; Silver-silica gel fractionation; Unresolved Complex Mixture (UCM)

Full Text:


HTML PDF XML

References


AOCS Official Methods of Analysis. Method Ca 6c-65. Hydrocarbons (Mineral oil); Ca 6c-65; AOCS: Champaign, Illinois, USA, 1997, pp 1–2.

Bastic M, Bastic L, Jovanovic JA, Spiteller G. 1978. Hydrocarbons and other weakly polar unsaponifiables in some vegetable oils. J. Am. Oil Chem. Soc. 55, 886–891. http://dx.doi.org/10.1007/BF02671413

Biedermann M, Grob K. 2009a. How "white" was the mineral oil in the contaminated Ukrainian sunflower oils? Eur. J. Lipid Sci. Technol. 111, 313–319. http://dx.doi.org/10.1002/ejlt.200900007

Biedermann M, Fiselier K, Grob K. 2009b. Aromatic hydrocarbons of mineral oil origin in foods: Method for determining the total concentration and first results. J. Agric. Food Chem. 57, 8711–8721. http://dx.doi.org/10.1021/jf901375e PMid:19728727

Biedermann M, Grob K. 2012. On-line coupled high performance liquid chromatography-gas chromatography for the analysis of contamination by mineral oil. Part 1: Method of analysis. J. Chromatogr. A, 1255, 56–75. http://dx.doi.org/10.1016/j.chroma.2012.05.095 PMid:22770383

Cert A, Moreda W. 1998. New method of stationary phase preparation for silver ion column chromatography: Application to the isolation of steroidal hydrocarbons in vegetable oils. J. Chromatogr. A, 823, 291–297. http://dx.doi.org/10.1016/S0021-9673(98)00183-6

EC, 2009. Commission Regulation (EC) No 1151/2009 of 27 November 2009 imposing special conditions governing the import of sunflower oil originating in or consigned from Ukraine due to contamination risks by mineral oil and repealing Decision 2008/433/EC; L 313. pp 36–40.

Fiorini D, Fiselier K, Biedermann M, Ballini R, Coni E, Grob K. 2008. Contamination of grape seed oil with mineral oil paraffins. J. Agric. Food Chem. 56, 11245–11250. http://dx.doi.org/10.1021/jf802244r PMid:18989969

Fiorini D, Paciaroni A, Gigli F, Ballini R. 2010. A versatile splitless injection GC-FID method for the determination of mineral oil paraffins in vegetable oils and dried fruit. Food Control, 21, 1155–1160. http://dx.doi.org/10.1016/j.foodcont.2010.01.011

Fiselier K, Fiorini D, Grob K. 2009a. Activated aluminium oxide selectively retaining long chain n-alkanes: Part II. Integration into an on-line high performance liquid chromatography-liquid chromatography-gas chromatography-flame ionization detection method to remove plant paraffins for the determination of mineral paraffins in foods and environmental samples. Anal. Chim. Acta. 634, 102–109. http://dx.doi.org/10.1016/j.aca.2008.12.011 PMid:19154817

Fiselier K, Fiorini D, Grob K. 2009b. Activated aluminium oxide selectively retaining long chain n-alkanes. Part I, description of the retention properties. Anal. Chim. Acta. 634, 96–101. http://dx.doi.org/10.1016/j.aca.2008.12.007 PMid:19154816

Fiselier K, Grob K. 2009. Determination of mineral oil paraffins in foods by on-line HPLC-GC-FID: lowered detection limit; contamination of sunflower seeds and oils. Eur. Food Res. Technol. 229, 679–688. http://dx.doi.org/10.1007/s00217-009-1099-8

ISO, 2013. International standard methods for animal and vegetable fats and oils. Method 17780. Determination of Aliphatic Hydrocarbons; 17780.

IUPAC, 1987. Standard Method 2.611 in Standard Methods for the Analysis of Oils, Fats and Derivatives. Determination of mineral oils in vegetable and animal fats and oils; 2611; Blackwell: Oxford.

Joint Research Centre. 2009. Final report on proficiency test on the determination of mineral oil in sunflower oil.

Lanz.n A, Albi T, Cert A, Graci.n J. 1994. The hydrocarbon fraction of virgin olive oil and changes resulting from refining. J. Am. Oil Chem. Soc. 71, 285–291.

Moret S, Barp L, Grob K, Conte LS. 2011. Optimised off-line SPE-GC-FID method for the determination of mineral oil saturated hydrocarbons (MOSH) in vegetable oils. Food Chem. 129, 1898–1903. http://dx.doi.org/10.1016/j.foodchem.2011.05.140

Moret S, Populin T, Conte LS, Grob K, Neukom HP. 2003. Occurrence of C15-C45 mineral paraffins in olives and olive oils. Food Addit. Contam. 20, 417–426. http://dx.doi.org/10.1080/0265203031000098687 PMid:12775460

Neukom HP, Grob K, Biedermann M, Noti A. 2002. Food contamination by C20-C50 mineral paraffins from the atmosphere. Atmos. Environ. 36, 4839–4847. http://dx.doi.org/10.1016/S1352-2310(02)00358-8

Populin T, Biedermann M, Grob K, Moret S, Conte L. 2004. Relative hopane content confirming the mineral origin of hydrocarbons contaminating foods and human milk. Food Addit. Contam. 21, 893–904. http://dx.doi.org/10.1080/02652030400001164 PMid:15666983

Tan YA, Kuntom A. 1993. Gas chromatographic determination of hydrocarbons in crude palm kernel oil. J. Assoc. Off. Anal. Chem. 76, 371–376.

Tranchida PQ, Zoccali M, Purcaro G, Moret S, Conte L, Beccaria M, Dugo P, Mondello L. 2011. A rapid multidimensional liquid-gas chromatography method for the analysis of mineral oil saturated hydrocarbons in vegetable oils. J. Chromatogr. A, 1218, 7476–7480. http://dx.doi.org/10.1016/j.chroma.2011.06.089 PMid:21774942

Wagner C, Neukom HP, Grob K, Moret S, Populin T, Conte LS. 2001. Mineral paraffins in vegetable oils and refinery byproducts for animal feeds. Mitt. Lebensmittelunters. Hyg. 92, 499–514.

Wagner C, Neukom HP, Galetti V, Grob K. 2001. Determination of mineral paraffins in feeds and foodstuffs by bromination and preseparation on aluminium oxide: method and results of a ring test. Mitt. Lebensmittelunters. Hyg. 92, 231–249.




Copyright (c) 2016 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.


Contact us grasasyaceites@ig.csic.es

Technical support soporte.tecnico.revistas@csic.es