Occurrence, spatial distribution and impact factors of 16 polycyclic aromatic hydrocarbons in milks from nine countries

PAHs, PCBs and OCPs in olive oil during the fruit ripening period of olive fruits

Because of their possible carcinogenic effects, it is crucial to determine levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in olive oils. However, there are a few studies about these pollutants' levels in olive oils and no other studies reported PAHs, PCBs and OCPs at the same time and during the ripening period of olives in olive oils. A modified clean-up technique was successfully applied for eliminating lipidic components. Additionally, this study does not just report the concentrations of these pollutants but also inspects the sources depending on the actual sampling site. Also, PCBs and OCPs carcinogenic risks in olive oil were reported for the first time in the literature. This study aims to present levels, carcinogenic risks, sources and concentration changes during the ripening period of these pollutants in olive oil. For this purpose, fruit samples for oil extraction were collected between the beginning of the fruit ripening and harvest period. Obtained olive oils from the fruits were extracted and cleaned up using the QuEChERS method. GC-MS and GC-ECD were used for the quantitative analysis of the targeted pollutants. The average concentrations for ∑₁₆PAHs, ∑₃₇PCBs and ∑₁₀OCPs were 222.48 ± 133.76 μg/kg, 58.26 ± 21.64 μg/kg and 25.48 ± 19.55 μg/kg, respectively. During the harvest period, the concentrations were in a decreasing trend. Calculated carcinogenic risks were above acceptable limits for all groups and traffic, wood-coal burning, atmospheric transport and previous uses were the main sources. Results of the source determination indicated that some possible sources could be prevented with regulations and precautions.

In-vial solid-phase extraction of polycyclic aromatic hydrocarbons in drug formulations stored in packaging containing rubber

Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous and persistent organic compounds that are significantly teratogenic, carcinogenic and mutagenic. Rubber stoppers commonly used in sterile formulation packaging materials often contain carbon black as the additive to enhance mechanical strength. However, PAHs may be formed during the production of carbon black, which could cause the drug formulations to be contaminated when contacting with the rubber stopper, and then enter the patient's body. The determination of PAHs in drug formulations is challenging, due to their trace amounts and matrix interference. Therefore, sample pretreatment is necessary and important. In this work, a novel technique, named in-vial solid-phase extraction (IVSPE), was developed for the selective extraction and enrichment of 16 PAHs in pharmaceuticals. The coated sample vial was directly used as the container for the whole process of sample pretreatment. As the solid-phase adsorbent, the coating was prepared by successively modifying the inner surface of a sample vial with polydopamine film and octadecylamine. PAHs could be selectively extracted through π-π stacking interaction and hydrophobic interaction, and then desorbed and enriched by a small amount of organic solvent. After systematic optimization of the coating preparation and the extraction process, the limits of detection and quantification of 16 PAHs were in the range of 0.002-0.60 ng mL^-1 and 0.007-2.00 ng mL^-1, respectively. Good linearities and precision of six repeated injections were obtained. The recoveries at three spiked concentration levels in normal saline were in the range of 62.72-106.90% with the relative standard deviation between 0.83% and 6.78%. Finally, PAHs in normal saline and powders for injection were extracted by established IVSPE, followed by separation and detection with high-performance liquid chromatography with a fluorescence detector and diode array detector (HPLC-FLD/DAD). It is worth noting that the preparation conditions of the adsorbent in the IVSPE method are mild, simple and green. Moreover, IVSPE has the advantages of having few work steps and avoiding the risk of contamination, because no special instrumentation or sample transfer is required. IVSPE could also be used for the pretreatment of multiple samples at the same time, which is beneficial to practical applications.

Rapid Determination of Oxygenated and Parent Polycyclic Aromatic Hydrocarbons in Milk Using Supercritical Fluid Chromatography-Mass Spectrometry

Liquid milks are consumed worldwide in large amounts, especially by adolescents and infants. Thus, their health quality linked with polycyclic aromatic hydrocarbon (PAH) contamination has attracted great concern. This study developed a rapid and sensitive supercritical fluid chromatography (SFC)-MS method to determine two typical oxygenated PAHs (OPAHs) and EU 15+1PAHs except for benzo[k]fluoranthene (BkF) in three types of liquid milks: 10 ultra heat treated (UHT) milks, 8 pasteurized milks, and 4 extended-shelf-life pasteurized milks. The instrumental analysis was 15 min with a recovery of 67.66-118.46%, a precision of 1.45-14.68%, detection limits of 0.04-0.24 μg/kg, and quantification limits of 0.13-0.78 μg/kg. We found 9-fluorenone, anthraquinone, 15 EU priority PAHs, and benzo[a]pyrene toxic equivalent quantity (BaPeq) in the 22 milk samples, which were 0.32-1.56 μg/kg, 0.40-1.74 μg/kg, 0.57-8.48 μg/kg, and 0.01-17.42 μg/kg, respectively. The UHT milks and whole fat milks showed higher PAH concentrations than other investigated samples, where the maximum levels of BaP and PAH4 were 0.77 and 3.61 μg/kg, respectively. PAH4 dominantly contributed to the PAH8 concentration and was detected in 73% and 32% of samples at more than 1.0 and 2.0 μg/kg, respectively. The results suggest that raw milks should be strictly monitored and extensively investigated for PAH4 and BaP concentrations for future risk assessment, limitations, and dietary guidance.

Trace-Level Determination of Polycyclic Aromatic Hydrocarbons in Dairy Products Available in Spanish Supermarkets by Semi-Automated Solid-Phase Extraction and Gas Chromatography-Mass Spectrometry Detection

Polycyclic aromatic hydrocarbons (PAHs) have been classified as priority pollutants by the U.S. Environmental Protection Agency (EPA) and the European Commission on the grounds of their carcinogenic, mutagenic and teratogenic properties. Because of their ubiquity in industrial processes and the environment, PAHs can reach milk and dairy products and, eventually, humans. In this work, a new method was developed to detect and quantify sixteen of the EPA’s priority PAHs in commercial milk and dairy products. The method involves liquid−liquid extraction (LLE) followed by semi-automated solid-phase extraction (SPE) to clean up and preconcentrate the analytes prior their detection and quantification by gas chromatography−mass spectrometry (GC−MS). The proposed method provided high precision (relative standard deviation < 11.5%), recoveries of 80−107% and low detection limits (1−200 ng/kg). The method was applied to analyze 30 dairy products, the majority of which contained some PAH at concentrations from 7.1 to 1900 ng/kg. The most-detected analytes were the lighter PAHs (naphthalene, acenaphthylene, fluorene and phenanthrene). None of the samples, however, contained more than four PAHs.

Concentrations, influencing factors, risk assessment methods, health hazards and analyses of polycyclic aromatic hydrocarbons in dairies: a review

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in dairies has been widely reported. Consumers may be overly exposed to PAHs through dairies causing health risks. Hazards can be reduced by controlling influencing factors in the full-chain of dairy production. This review briefly introduces research trends and analytical methods concerning PAHs in dairies. Additionally, this review discusses influencing factors of PAH concentrations in various dairies to avoid PAHs' formation and accumulation during manufacture. Relevant regulations are referred to and the reported risk assessment methods are summarized. Furthermore, indicators of health risks including TEQBaP, the number and the rate of over-standard are calculated based on PAH concentrations. Through analyses, we find PAH and BaP contamination in dairies are complex problems depending on environment, processing and storage. There was a significant correlation between fat contents and PAH concentrations. Results of infant formula in certain research were worrying and those of smoked cheeses are remarkably high indicating the dangerous smoking process. It is significant to monitor PAHs and calculate TEQBaP from meadows to feeders. Moreover, the existing regulations are insufficient and need strengthening. The data and discussions in this review contribute to worldwide Big Data, further scientific investigation and regulations for PAHs in dairies.

Polycyclic Aromatic Hydrocarbons (PAHs) Sample Preparation and Analysis in Beverages: A Review

The monitoring of food contaminants is of interests to both food regulatory bodies and the consumers. This literature review covers polycyclic aromatic hydrocarbons (PAHs) with regard to their background, sources of exposures, and occurrence in food and environment as well as health hazards. Furthermore, analytical methods focusing on the analysis of PAHs in tea, coffee, milk, and alcoholic samples for the last 16 years are presented. Numerous experimental methods have been developed aiming to obtain better limits of detections (LODs) and percent recoveries as well as to reduce solvent consumption and laborious work. These include information such as the selected PAHs analyzed, food matrix of PAHs, methods of extraction, cleanup procedure, LOD, limits of quantitation (LOQ), and percent recovery. For the analysis of tea, coffee, milk, and alcoholic samples, a majority of the research papers focused on the 16 US Environmental Protection Agency PAHs, while PAH4, PAH8, and methylated PAHs were also of interests. Extraction methods range from the classic Soxhlet extraction and liquid–liquid extraction to newer methods such as QuEChERS, dispersive solid-phase microextraction, and magnetic solid-phase extraction. The cleanup methods involved mainly the use of column chromatography and SPE filled with either silica or Florisil adsorbents. Gas chromatography and liquid chromatography coupled with mass spectrometry or fluorescence detectors are the main analytical instruments used. A majority of the selected combined methods used are able to achieve LODs and percent recoveries in the ranges of 0.01–5 ug/kg and 70–110%, respectively, for the analysis of tea, coffee, milk, and alcoholic samples.

The loss and fate of BaA, Chr, BbF, and BaP (PAH4) tracked by stable isotope during frying

The objective of this work was to accurately quantify the loss of benzo(a)anthracene, chrysene, benzo(b)fluoranthene, and benzo(a)pyrene (PAH4) and investigate the fate of the lost PAH4 into their derivatives during frying. Stable isotopes (PAH4-d12) were used to simulate the loss and track the conversion of PAH4. The results showed that the rate of loss of PAH4-d12 increased with the increase of frying temperature and the loss rate of benzo(a)pyrene-d12 was the largest, indicating that benzo(a)pyrene had the strongest chemical reactivity during frying. Moreover, the identification of five PAH4 derivatives has confirmed the conversion of lost PAH4. Finally, the loss of PAH4 during frying positively correlated with the oxidation of oil, and a conversion mechanism of PAHs to derivatives was proposed. This work directly proved the loss and conversion of PAH4 and provided a comprehensive perspective for studying the changes in PAH4 during frying.

Polycyclic Aromatic Hydrocarbons in Foods: Biological Effects, Legislation, Occurrence, Analytical Methods, and Strategies to Reduce Their Formation

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds comprised of carbon and hydrogen molecules in a cyclic arrangement. PAHs are associated with risks to human health, especially carcinogenesis. One form of exposure to these compounds is through ingestion of contaminated food, which can occur during preparation and processing involving high temperatures (e.g., grilling, smoking, toasting, roasting, and frying) as well as through PAHs present in the soil, air, and water (i.e., environmental pollution). Differently from changes caused by microbiological characteristics and lipid oxidation, consumers cannot sensorially perceive PAH contamination in food products, thereby hindering their ability to reject these foods. Herein, the occurrence and biological effects of PAHs were comprehensively explored, as well as analytical methods to monitor their levels, legislations, and strategies to reduce their generation in food products. This review updates the current knowledge and addresses recent regulation changes concerning the widespread PAHs contamination in several types of food, often surpassing the concentration limits deemed acceptable by current legislations. Therefore, effective measures involving different food processing strategies are needed to prevent and reduce PAHs contamination, thereby decreasing human exposure and detrimental health effects. Furthermore, gaps in literature have been addressed to provide a basis for future studies.

Simultaneous Determination of Typical Chlorinated, Oxygenated, and European Union Priority Polycyclic Aromatic Hydrocarbons in Milk Samples and Milk Powders

An increasing number of studies have suggested that PAH contamination in dairy products demands high concern. This study established an efficient determination method for the European Union 15 + 1 PAHs and four PAH derivatives in dairy samples using a QuEChERS method coupled with GC-QqQ-MS. The optimized method obtained a recovery of 63.38-109.17% with a precision of 3.82-15.62%, and the limit of detection and limit of quantification were 0.08-0.78 and 0.27-2.59 μg/kg, respectively. The validated method was then successfully applied to identify the 20 PAHs in 82 dairy samples, including 43 commercial milk samples and 39 milk powders. The total PAH concentrations ranged from 2.37 to 11.83 μg/kg, and benzo[a]pyrene was only quantified in one milk and one milk powder sample at 0.35 and 0.42 μg/kg, respectively. The concentrations of PAH4 in milk samples and milk powders were not quantified (nq)-3.99 and nq-4.51 μg/kg, respectively. The results confirmed the appreciable occurrence of PAHs in dairy products, especially in infant formula. The data in this study provide a scientific basis for assessment on origin tracing, dietary exposure, and health risk of PAHs and their derivatives.