A systematic evaluation of aluminium oxide (Alox) on mineral oil saturated hydrocarbons (MOSH) recovery and dietary exposure from vegetable oils in China

A method based on an off‐line large‐scale solid phase extraction (SPE) approach combined with conventional gas chromatographic‐flame ionization detection (GC‐FID) was developed to determine the mineral oil‐saturated hydrocarbons (MOSH) in vegetable oils. A large‐scale SPE column loaded with 10 g of activated silica gel impregnated with 1% silver nitrate which was used to retain lipids and olefins in vegetable oils and the MOSH in the oil samples was eluted with hexane. Then 2 μL concentrated solution was splitlessly injected into a common GC‐FID instrument. The quantification limit reached 2.5 mg/kg when the MOSH fraction was concentrated to 0.1 mL. The accuracy of this procedure, as assessed by measuring the recoveries from spiked oil samples, was higher than 80%. This procedure was applied to analyze the MOSH in 38 commercial vegetable oils from Chinese market, which was the first survey of mineral oil contaminant in Chinese edible oils. The oil samples contaminated with different levels of MOSH, among which, 15 samples contained no mineral oils and 3 samples were contaminated with more than 50 mg/kg of MOSH. The highest contamination level was found in one of rice oils, in which the concentration of MOSH was up to 713.36 mg/kg. Of the 9 types of oils analyzed, camellia oil contained MOSH ranging between 6.76 and 78.49 mg/kg, averaging 46.72 mg/kg, indicating a higher contamination level than other types of oils. The results suggested that it is necessary to routinely detect mineral oil contamination in vegetable oils for food safety.

An interlaboratory study was conducted in 2014 to evaluate a method for determining mineral oil saturated hydrocarbons in vegetable oils and fats. Samples were dissolved in an apolar solvent and subjected to a purification on silica gel impregnated with silver nitrate. The final extract was analyzed using gas chromatography with a flame ionization detection. Quantification was performed using internal standardization. Six samples were assayed for mineral oil saturated hydrocarbons by 21 collaborating laboratories from nine countries. Sample matrices included olive, olive pomace, sunflower, soybean, and rapeseed oils. Comparing two types of integration of the unresolved complex mixture area, it was decided to recommend in the test method the integration of the natural hydrocarbons only considering the highest peaks of n‐alkanes. Repeatability (RSDr) ranged from 3.7 to 10.5% and reproducibility (RSDR) ranged from 10.3 to 25.7% for samples containing greater than 35 mg/kg of mineral oil saturated hydrocarbons. The method provides acceptable results for quantification of mineral oil saturated hydrocarbons in edible oils, from 50 to 1000 mg/kg.Practical applications: Standardized methods for mineral oil saturated hydrocarbon determination in vegetable oils and fats, are not yet available. This paper describes the validation of a method for the quantification of the saturated aliphatic hydrocarbons and it provides the results from an international collaborative trial.A method for the determination of mineral oil saturated hydrocarbons in vegetable oils by GC/FID, after purification on AgNO3‐silica gel, was validated during an international collaborative study.

Effect of dietary pristane and other saturated mineral oils (MOSH) on autoimmune arthritis in rats

An offline solid-phase extraction (SPE) approach combined with a large-volume injection (LVI)-gas chromatography-flame ionization detector (LVI-GC-FID) is improved for routine analysis of mineral oil saturated hydrocarbons (MOSH) in vegetable oils. The key procedure of the method consists in using offline SPE columns for MOSH purification. The SPE column packed with 1% Ag-activated silica gel was used to separate MOSH from triglycerides and olefins in variety of vegetable oils. The eluent of MOSH fraction was only 3 mL and the concentration step was quick with little evaporation loss. The limit of quantification (LOQ) of the method was 2.5 mg/kg and the linearity ranged from 2 to 300 mg/kg. The accuracy was assessed by measuring the recoveries from spiked oil samples and was higher than 90%. Twenty-seven commercial vegetable oils were analyzed, and different levels of MOSH contamination were detected with the highest being 259.4 mg/kg. The results suggested that it is necessary to routinely detect mineral oil contamination in vegetable oils for food safety.

The purpose of this study was to investigate the fate and effects of mineral oil saturated hydrocarbons (MOSH) in female Fischer 344 rats. Animals were fed control diet or diet containing various MOSH mixtures at concentrations ranging from 40 to 4000 mg/kg feed for up to 120 days. MOSH were analysed in liver, spleen, adipose tissue and remaining carcass at different sampling times. In addition to clinical effects, liver microgranulomas, hepatic inflammation, and disruption of the immune function were the main toxicological endpoints investigated. Arthritis symptoms were specifically studied in dark agouti rats. The results indicate that accumulation of MOSH depends on the mixture tested but always occurred predominantly in the liver and to a lesser extent in adipose tissue and spleen. Strong differences exist between liver and adipose tissue in terms of accumulated hydrocarbons: whereas in adipose tissue the accumulated fraction corresponds to the most volatile part of the administered mixture, in the liver, the most volatile as well as the highest boiling part of the mixture are almost absent. Also the types of hydrocarbons differ. When exposure ceases, a significant decrease of MOSH concentration was observed in the liver, but not in adipose tissue. MOSH exposure results in a significant increase in absolute and relative liver weights, the effect being dose-related, but also dependent on the mixture tested. There were large differences in the ability of the different mixtures to induce liver granulomas. The highest incidence was observed with the mixture containing the highest proportion of n-alkanes, suggesting that this fraction could play a significant role in the development of hepatic granulomas. No effects were found on the immune function, irrespective of the mixture or the dose tested.

Lipsticks and lip care products may contain saturated hydrocarbons which either stem from mineral oil saturated hydrocarbons (MOSH) or are synthetic, that is polyolefin oligomeric saturated hydrocarbons (POSH). Some of these hydrocarbons are strongly accumulated and form granulomas in human tissues, which prompted Cosmetics Europe (former Colipa) to issue a recommendation for their use in lip care and oral products. From 2012 to 2014, MOSH+POSH were determined in 175 cosmetic lip products taken from the Swiss market in order to estimate their contribution to human exposure. Mineral oil saturated hydrocarbons and POSH were extracted and analysed by GC with FID. Areas were integrated as a total as well as by mass ranges with cuts at n-C25 and n-C34 to characterize the molecular mass distribution. About 68% of the products contained at least 5% MOSH+POSH (total concentration). For regular users, these products would be major contributors to their MOSH+POSH exposure. About 31% of the products contained more than 32% MOSH+POSH. Their regular usage would amount in an estimated MOSH+POSH exposure exceeding the highest estimated dietary exposure. The majority of the products contained hydrocarbons with a molecular mass range which was not in line with the recommendations of Cosmetics Europe. Taking into account that material applied to the lips largely ends up being ingested, MOSH and POSH levels should be reduced in the majority of cosmetic lip products. As the extensive evaluation of the data available on MOSH (EFSA J., 10, 2012, 2704) did not enable the specification of limits considered as safe, the present level of dietary exposure and its evaluation as 'of potential concern' provide the relevant bench mark, which means that lip products should contain clearly less than 5% MOSH+POSH.

Rice bran oil is an edible oil which is used in food preparation. In Thailand, Standard conditions and methods in detecting mineral oil hydrocarbons (MOH) were not Regulated. Therefore all rice bran oil quality and safety control was done abroad. This research proposed determination conditions in detecting mineral oil hydrocarbon using an off-line liquid chromatography with gas chromatography flame ionization detector. This method was adapted from ISO 17780 : animal and vegetable fats and Oils determination of aliphatic hydrocarbons in vegetable oil. Silver nitrate impregnated With silica gel was used to purify and separate mineral oil saturated hydrocarbon (MOSH). GC-FID using pulse splitless injection system combining with pulse time at 0.5 minute, Inlet temperature at 250 °C, and inlet pressure at 30 psi were considered to be the best Conditions due to the largest area under the graph. The hump in the chromatogram Represents the mass fraction of MOSH. This fraction is only presented in an eluent fraction Of 55 mL hexane. Three crude rice bran oil samples were analysed, RBACTG25A, RBACTF27A, and RBACTF22A. Different levels of MOSH were detected with the highest Being RBACTF27A (164.2 mg/kg) followed by RBACTG25A (90.5 mg/kg) and RBACTF22A(34.1 mg/kg). The comparison between the result obtained and reference data showed a slight difference due to the differences in sampling and injection method used. However, it gives out the same trend as the reference data. The amount of C25-C35 MOSH which is the targe hydrocarbon is approximately 90% which is considered to be high and can not be refined to edible oil.

Optimised off-line SPE–GC–FID method for the determination of mineral oil saturated hydrocarbons (MOSH) in vegetable oils

Consuming edible vegetable oil (EVO) is highly beneficial for human health due to its abundant nutrients, yet it might pose a risk if contaminated. Common pollutants such as mycotoxins, pesticides, heavy metals, and mineral oil will likely occur during harvesting, industrial processing, and environmental pathways. This review focuses on mineral oil, a type of petrogenic pollutant that can be further classified into two subgroups: mineral oil saturated hydrocarbon (MOSH) and mineral oil aromatic hydrocarbon (MOAH). Due to its significant consumption, exposure to MOSH/MOAH in EVO has a detrimental impact on human health, to the point that both subgroups are considered hazardous. Indeed, MOSH can bioaccumulate in certain organs, and certain MOAH compounds have a strong potential to cause cancer. The European Food Safety Association (EFSA) has established standards for vegetable oil, updated in 2022, which provide a maximum limit of 13 mg MOSH/kg and 0.5 mg MOAH/kg. Additionally, a pragmatic monitoring method is implemented, including identifying and evaluating MOSH/MOAH presence in the specific matrix using analytical techniques that can accurately measure their quantities. Despite the existence of various techniques, the Liquid Chromatography–Gas Chromatography-Flame Ionisation Detector (LC-GC-FID) technique stands out for its adaptability, efficiency, sensitivity, and excellent reproducibility, even in the presence of complicated matrix and analyte. Therefore, this study comprehensively explains the operating principle, sample preparation, column selection, and assessment results. Various advanced techniques were employed to detect, measure, and distinguish individual MOSH/MOAH structures. These methods involved using additional instruments; in certain instances, innovative approaches were also implemented. In this review, the focus is on elucidating the presence of MOSH/MOAH contamination in EVO and delving into the LC-GC-FID method, the prevailing approach for quantification, with a comprehensive exploration of its intricacies.

A method is described to lower the detection limit for mineral oil saturated hydrocarbons (MOSH) in foods as compared to the on-line HPLC–LC–GC–FID method described previously: samples are preseparated (enriched) by conventional liquid chromatography on activated silica gel and activated aluminum oxide. The silica gel retains up to 1 g of fat or oil, the aluminum oxide up to 2 mg n-alkanes of at least 24 carbon atoms, i.e. plant paraffins which may severely hinder the analysis of the mineral paraffins. The efficacy of the method is shown for an apple and sunflower oil. Oils extracted from manually harvested seeds grown in fields or gardens contained between 0.14 and 0.77 mg/kg MOSH. In the oils from seeds sampled in an oil mill, this value was increased to 3.3–9.3 mg/kg, indicating a contamination during harvest, transport and/or storage. Concentrations in commercial refined sunflower oils ranged between 2.7 and 32 mg/kg, averaging 11.2 mg/kg. Since deodorization removes a substantial part of the MOSH, this suggests a further contamination in the oil mill. The contamination affected all samples at a similar level, indicating that it occurs systematically by the presently used technology.

In the absence of a functional barrier, mineral oil hydrocarbons from printing inks and recycled fibres tend to migrate from paper-based food-packaging materials through the gas phase into dry food. Concentrations easily far exceed the limit derived from the acceptable daily intake (ADI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Since the estimation of long-term migration into the food by testing at 40°C for 10 days is difficult, it seems preferable (and easier) to use the mineral oil content in the paperboard. Evaporation experiments showed that hydrocarbons eluted up to about n-C24 are sufficiently volatile for relevant migration into dry food: in worst-case situations, about 80% migrate into the packed food. The extraction of the paperboard was optimised to give good recovery of the relevant hydrocarbons, but to discriminate against those of high molecular mass which tend to disturb gas chromatographic analysis in on-line coupled normal phase HPLC-GC-FID. Even though some of the relevant hydrocarbons had already evaporated, the average concentration of < C24 mineral oil saturated hydrocarbons (MOSH) in the paperboard boxes of 102 products from the Swiss and Italian market was 626 mg kg−1. Nearly 15% of investigated boxes still contained more than 1000 mg kg−1 < C24 MOSH up to over 3000 mg kg−1 (maximum = 3500 mg kg−1). This amount of MOSH in the board have the potential of contaminating the packed food at a level exceeding the limit, derived from the JECFA ADI, hundreds of times.

Mineral oil hydrocarbons (MOH) are present in many fats and oils as well as foods prepared thereof. A survey of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in different types of vegetable fats and oils is reported. Contents of MOSH/MOAH were quantified using liquid chromatography online‐coupled to gas chromatography with flame‐ionization detection (LC‐GC‐FID). Cocoa butter (n = 142) showed levels from &lt;LOQ (2.5 mg kg−1) to 162 mg kg−1 ΣMOSH (sum of C10–C50) and &lt;LOQ to 55 mg kg−1 ΣMOAH, in palm oil (n = 21) ΣMOSH were quantified from &lt;LOQ to 124 mg kg−1 and ΣMOAH from &lt;LOQ to 39 mg kg−1. Sunflower oil showed lower levels: ΣMOSH were determined in the range of &lt;LOQ to 17 mg kg−1 and MOAH were not observed at all. A possible influence of deodorization and a subsequent minimization of MOSH/MOAH was investigated. Systematic model‐experiments were performed on laboratory scale using spiked cocoa butter. Significant minimization of volatile MOH subfractions ≤C24 were observed at a deodorization temperature of 210 °C. Deodorization can be considered as an important processing step to reduce or even remove volatile MOSH/MOAH ≤C24.Practical Applications: Regardless of their possible entry routes into the food chain, volatile fractions of MOSH/MOAH can be removed by deodorizing vegetable fats and oils. This model‐study identifies the temperatures of deodorization that provide a significant improvement toward minimization of undesired MOSH/MOAH.

Screening for mineral oil hydrocarbons in vegetable oils by silver ion–planar solid phase extraction

A method was developed for the determination of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in edible oils, achieving similar limits of quantification than those obtained by online extraction methodologies, i.e., 0.5 mg/kg. The isolation of MOSH and MOAH was performed in a silver nitrated silica gel stationary phase prior to their analysis by gas chromatography–flame ionization detector (GC-FID). To improve the sensitivity, the simulated on-column injection method, using a suitable liner, was optimized. The method was validated at 0.5, 10.0 and 17.9 mg/kg, and recoveries ranged from 80 to 110%. Intra and inter-day precision were evaluated at the same levels, and relative standard deviation (RSD) was lower than 20%. The method was applied to a total of 27 samples of different types of oil previously analyzed in an accredited laboratory, detecting MOSH up to 79.2 mg/kg and MOAH up to 22.4 mg/kg.

Spectroscopic measurement and dielectric relaxation study of vegetable oils