Combining relationship indices, human risk indices, multivariate statistical analysis and international guidelines for assessing the residue levels of USEPA-PAHs in seafood

Search for new green natural solid phases for sample preparation for PAHs determination in seafood samples followed by LC and GC-MS/MS analysis

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic organic pollutants found in various environments, notably aquatic ecosystems and the food chain, posing significant health risks. Traditional methods for detecting PAHs in food involve complex processes and considerable reagent usage, raising environmental concerns. This study explores eco-friendly approaches suing solid phases derived from natural sources in matrix solid phase dispersion. We aimed to develop, optimize, and validate a sample preparation technique for seafood, employing natural materials for PAH analysis. Ten natural phases were compared with a commercial reference phase. The methodology involved matrix solid phase dispersion and pressurized liquid extraction, followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Three solid phases (perlite, sweet manioc starch, and barley) showed superior performance in LC-MS/MS and were further evaluated with gas chromatography-tandem mass spectrometry (GC-MS/MS), confirming perlite as the most effective phase. Validation followed Brazilian regulatory guidelines and European Community Regulation 2021/808/EC. The resulting method offered advantages in cost-effectiveness, reduced environmental impact, cleaner extracts, and enhanced analytical performance compared to the reference solid phase and LC-MS/MS. Proficiency analysis confirmed method reliability, with over 50% alignment with green analytical chemistry principles. In conclusion, this study developed an environmentally sustainable sample preparation technique for seafood analysis using natural solid phases, particularly perlite, for PAH determination.

Distribution, composition and risk assessment of hydrocarbon residue in surficial sediments of El-Dakhla, El-Kharga and El-Farafra oases, Egypt

This work examined the polycyclic aromatic hydrocarbons (PAHs) and n-alkanes quantities, sources, and hazards in sediments collected from the Egyptian Western Desert Oases namely: Dakhla, Kharga and Farafra oases. The n-alkane (C9-C20) residue concentrations have ranged from 0.66 to 2417.91 µg/g recorded for the three Oases. On the other hand, the total n-alkane ranged from 448.54 µg/g to 8442.60 µg/g. Higher carbon preference index (CPI) values (> 1.0) proposed that the natural sources could be the main contributor to n-alkanes in the Oases sediment. GC-MS/MS (selected reaction monitoring (SRM) method) was used for the determination of the ΣPAHs concentrations in the studied sediments. The ΣPAHs concentrations (ng/g, dry weight) in the studied three Oases varied from 10.18 to 790.14, 10.55 to 667.72, and from 38.27 to 362.77 for the Kharga, Dakhla and Farafra Oases, respectively. The higher molecular weight PAHs were the most abundant compounds in the collected samples. Assessing potential ecological and human health issues highlighted serious dangers for living things and people. All the investigated PAHs had cancer risk values between 1.43 × 10-4 and 1.64 × 10-1, this finding suggests that PAHs in the samples under study pose a moderate risk of cancer. The main sources of PAHs in this study are biomass, natural gas, and gasoline/diesel burning emissions.

Between-bottle homogeneity test of new certified reference materials employing wavelength dispersive X-ray fluorescence spectrometry

BACKGROUND

A pilot study has being carried out at our laboratories, with international collaborators, to develop seven certified reference materials (CRMs), which have matrices of mainly soil and biological tissues. The CRMs will be certified for macro-, micro- and trace elements for environmental, toxicological, agronomic and nutritional purposes. Homogeneity of element concentrations is a critical step in the production process of CRMs. This work employs wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) to test between-bottle homogeneity of the CRMs.

RESULTS

The relative standard deviation (RSD), relative average deviation, Skewness and Kurtosis of element contents in seven bottles out of 80 bottles of each CRM were considered to assess homogeneity in terms of variability and distribution. More than 50% of the number of quantified elements recorded RSD between 2 and 5%. Hence, based on an in-house classification, the intended CRMs recorded excellent to good between-bottle homogeneity. Nevertheless, the contents of some elements (Ni, Rb, Zn and Br) experienced high RSD values (> 10%). The Skewness and Kurtosis values of most elements are around one indicating symmetric distribution and thus have an absence of tailing relative to the normal distribution.

CONCLUSIONS

WD-XRF provides fit for purpose data for assessment of initial between-bottle homogeneity in terms of rapidity, ease of use, multi-element quantification and sample non-destruction.