Organophosphate esters and their metabolites in eggs from Vietnam.

Data on the occurrence of organophosphate tri-esters (tri-OPEs) and their metabolites (di-OPEs) in hen's eggs are scarce. Therefore, 200 egg samples were gathered in 2023 in Hanoi, Vietnam and analysed by UHPLC-Q-Exactive HRMS. The majority of these compounds were detected, with tris(2-ethylhexyl) phosphate (0.

Organophosphate esters and their metabolites in silver pomfret (Pampus argenteus) of the Vietnamese coastal areas: Spatial-temporal distribution and exposure risk.

A large number of studies on organophosphate esters (tri-OPEs) in marine organisms have not assessed the simultaneous occurrence of tri-OPEs and their metabolites (di-OPEs) in these species. This research investigated the concentration and geographical distribution of 15 tri-OPEs and 7 di-OPEs in 172 samples of Pampus argenteus that were collected annually from 2021 to 2023 at three distinct locations along the Vietnamese coast. As a result, tri-OPEs and di-OPEs were detected in numerous fish samples, indicating their widespread spatial and temporal occurrence in marine fish and pointing out the importance of monitoring their levels.

Endocrine-disrupting chemicals in Vietnamese marine fish: Occurrence, distribution, and risk assessment.

The release of endocrine-disrupting chemicals (EDCs) into the aquatic environment, specifically the oceans, is increasing, leading to adverse effects on the marine ecosystem. Using optimized QuEChERS extraction methods, the study created the first contamination profiles of 44 EDCs, including organic ultraviolet compounds, pharmaceutically active compounds, hormones, and phthalate esters, in 114 fish muscle samples from five species collected along the Vietnamese coast. The study found that largehead hairtail exhibited the highest total EDCs at 208.

Occurrence, biomagnification, and risk assessment of parabens and their metabolites in marine fish: The case study of Vietnam.

Parabens have emerged as the primary preservative of choice in numerous consumer goods, prompting growing apprehension regarding their potential for human exposure. The study employed the optimized QuEChERs sample extraction method and the UHPLC-Q-Orbitrap HRMS system to generate the initial contamination profiles of seven parabens and their four metabolites in a total of 114 fish samples found along the coastline of Vietnam. The findings of the study indicated that methylparaben was the predominant substance detected, exhibiting the highest concentration in the largehead hairtail (Trichiurus lepturus) species at 32.

Occurrence, distribution, and risk assessment of halogenated organic pollutants (HOPs) in marine fish muscle: The case study of Vietnam.

Halogenated organic pollutants (HOPs), including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and chlorophenols (CPs), were identified in three marine fish species in Vietnam. Total PCBs, OCPs, and CPs concentrations ranged from 4.5 to 711.

Geographical origin traceability of Sengcu rice using elemental markers and multivariate analysis.

Multi-element analysis combined with chemometric method has been used to investigate the distinguish between Sengcu rice and other types of rice origins in Vietnam. In Sengcu rice, As, Ba Sr, Pb, Ca, Se were confirmed as the key elements for geographical traceability among three fields of Lao Cai, whereas Al, Ca, Fe, Mg, Ag, As were major factors to distinguish between Sengcu and other types of rice. Based on linear discriminant analysis and partial least squares-discriminant analysis model, overall correct identification rates distinguishing between Sengcu and other types of rice were approximately 100% in both training and validation test.

A Combination of Chromatography with Tandem Mass Spectrometry Systems (UPLC-MS/MS and GC-MS/MS), Modified QuEChERS Extraction and Mixed-Mode SPE Clean-Up Method for the Analysis of 656 Pesticide Residues in Rice.

The emerging ungovernable application of pesticides in rice farming has attracted public concerns as these hazardous chemicals leave long-lasting environmental impacts and cause severe health effects. Here, an optimized analytical method was proposed for the measurement of 656 pesticide residues in rice samples collected in Vietnam. We utilized chromatography with tandem mass spectrometry systems (UPLC-MS/MS and GC-MS/MS) combined with a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method and adopted a mixed-mode SPE clean-up method for the analysis.

Pesticides in edible mushrooms in Vietnam.

Maximum residue limits (MRLs) for pesticides have been established for edible mushrooms in order to control quality and ensure benefits of consumers in numerous countries, especially areas comprising Europe. In this study, by means of optimising extract purification conditions, a high sensitivity and reliability method to simultaneously determine 180 pesticides in mushrooms has been proposed. Matrix effects were minimised by combining QuEChERS extraction and a mixed mode of SPE cleaned up with different adsorbent materials after sample preparation.

Simultaneous Determination of 18 Polycyclic Aromatic Hydrocarbons in Daily Foods (Hanoi Metropolitan Area) by Gas Chromatography⁻Tandem Mass Spectrometry.

Polycyclic aromatic hydrocarbons (PAHs)-a large group of organic compounds-are extremely hazardous to human health. In this study, the 198 samples from six groups of daily food products in the Hanoi metropolitan area were collected and prepared by the QuEChERS sample treatment technique. The detection and identification of PAHs were obtained by gas chromatography⁻tandem mass spectrometry (GC⁻MS/MS) determination.

Optimization of Sample Preparation for Detection of 10 Phthalates in Non-Alcoholic Beverages in Northern Vietnam.

A novel method was developed for the sensitive, cheap and fast quantitation of 10 phthalates in non-alcoholic beverages by liquid⁻liquid extraction (LLE) combined with gas chromatography tandem mass spectrometry (GC-MS/MS). The best results were obtained when -hexane was used as extraction solvent. A central composite design (CCD) was applied to select the most appreciated operating condition.

Effect of some parameters on the rate of the catalysed decomposition of hydrogen peroxide by iron(III)-nitrilotriacetate in water.

The decomposition rate of H(2)O(2) by iron(III)-nitrilotriacetate complexes (Fe(III)NTA) has been investigated over a large range of experimental conditions: 3 < pH < 11, [Fe(III)](T,0): 0.05-1 mM; [NTA](T,0)/[Fe(III)](T,0) molar ratios : 1-250; [H(2)O(2)](0): 1 mM-4 M) and concentrations of HO· radical scavengers: 0-53 mM. Spectrophotometric analyses revealed that reactions of H(2)O(2) with Fe(III)NTA (1 mM) at neutral pH immediately lead to the formation of intermediates (presumably peroxocomplexes of Fe(III)NTA) which absorb light in the region 350-600 nm where Fe(III)NTA and H(2)O(2) do not absorb.

Hydroxyl radical involvement in the decomposition of hydrogen peroxide by ferrous and ferric-nitrilotriacetate complexes at neutral pH.

The relative rates of degradation of three hydroxyl radical probe compounds (atrazine, fenuron and parachlorobenzoic acid (pCBA)) by Fe(III)/H(2)O(2) (pH = 2.85), Fe(III)NTA/H(2)O(2) (neutral pH), Fe(II)/O(2), Fe(II)NTA/O(2), Fe(II)/H(2)O(2) and Fe(II)NTA/H(2)O(2) (neutral pH) have been investigated using the competitive kinetic method. Experiments were carried out in batch and in semi-batch reactors, in the dark, at 25 °C.