Multiresidue method for triazines and pyrethroids determination by solid-phase extraction and gas chromatography-tandem mass spectrometry.

This research aimed at implementing and validating a method for analysis of pesticide residues in crops. QuEChERS extraction method with PSA purification was used following analyzes by gas chromatography with tandem mass spectrometry in Selected Reaction Monitoring mode. A short run method was successfully developed for the determination of 41 pesticides, confirmed by two precursor-products for each analyte. The calibration curve for each analyte was linear at concentration range from 1 to 500 µg kg-1 with correlation coefficients higher than 0.99, low limits of detection (0.03 - 10.22 µg kg-1) and satisfactory precision. The developed method was used to investigate apples; mangos; strawberries; cucumbers and tomatoes from the Rio de Janeiro Food Distribution Center (CEASA).Most of the targeted pesticides (78%) were below detection limits. Apple and strawberry presented the highest pesticide contamination levels, many of which are not authorized by tthe Brazilian national regulatory agency (ANVISA).

Hydrocarbons and trace metals in mussels in the Macaé coast: Preliminary assessment for a coastal zone under influence of offshore oil field exploration in southeastern Brazil.

Concentrations of PAHs and metals were obtained from mussels collected in beaches, coastal island and estuary of the Macaé coast, the main operational basin for offshore oil exploration in Brazil. This survey provides reference levels for scenarios of increasing exploration, as well as for other areas of the coast undergoing urbanization to support exploration. As expected, urban areas such as the Macaé river estuary presented high concentrations of PAHs, although unsuspected sites such the island also presented signs of contamination. PAH in mussels originated from pyrolytic and petrogenic sources. Metals were typical of non-contaminated coastal environments, although Cr concentrations were above Brazilian Reference Levels.

Marine sponges as bioindicators of oil and combustion derived PAH in coastal waters.

The present study evaluates the potential of Hymeniacidon heliophila as bioindicator of PAH contamination. For this, concentration of 33 PAH was determined in organisms from sites with different contamination level including the heavily polluted Guanabara Bay, Rio de Janeiro, and less impacted coastal areas. PAH concentration and typology were determined in sponges collected from different depths and in two different seasons. The brown mussel broadly studied as bioindicator was also sampled from the same sites for comparison. Both species provided similar information on total PAH concentration which is related to site contamination level. Sponges, however, revealed slight tendency to accumulation of combustion-derived PAH in relation to petrogenic compounds. Differences in PAH typology between species may derive from the interspecific variation in particle size ingestion. Different hydrocarbon typologies were observed in sponges from dry and wet season and PAH concentration varied with depth. H. heliophila may be used as an alternative approach to investigate the presence and sources of PAH in estuarine areas.

Formation and identification of PAHs metabolites in marine organisms.

In this study, the development of the technique APCI(+) LC/MS/MS allowed the detection of phenanthrene, pyrene and metabolites of alkyl homologs in fish bile (in situ) and in urine of crabs. Laboratory experiments were carried out exposing crabs from an unpolluted mangrove (Barra de Guaratiba) to phenanthrene, and to the alkylated homologs 1-methyl phenanthrene and 2,6,9-trimethyl phenanthrene. Urine samples were collected at 0, 24, 48, 72, and 96 h. Fishes were captured from strategic sites from Guanabara Bay. Hydroxylated metabolites of phenanthrene, epoxides, orthoquinone and glucoside conjugates were identified in both samples. The method APCI(+) LC/MS/MS showed to be effective in a preliminary assessment of phenanthrene metabolite formation, although the low concentrations of 1-methyl phenanthene and 2,6,9-trimethyl phenanthrene did not allow a systematic evaluation of data. The method, however, proved to be excellent tool for studies of PAHs metabolites due to the high selectivity, sensitivity and separation attained.

Biomarkers of PAHs exposure in crabs Ucides cordatus: laboratory assay and field study.

Pyrene metabolites in urine and micronucleus in haemocytes of crabs (Ucides cordatus) were tested as biomarkers of exposure to oil derived PAHs in mangrove sediments. The goal was to verify how well pyrene metabolites in urine represent levels of oil contamination in mangroves and whether the micronuclei assay indicates exposure. For this, bioassays were performed using crabs from clean and contaminated areas, and field studies were conducted in four mangroves. Results of the bioassay show that U. cordatus assimilates, metabolises, and excretes pyrene in urine as pyrene-1-glucoside, pyrene-sulphate and pyrene-conjugate. OH-pyrene-sulphate was the major metabolite produced/excreted over 120 h of observation by crabs from the clean mangrove. The production/excretion of pyrene-1-glucoside in this case increased linearly with time at a rate of 2.3 x 10(-10)mol L(-1)day(-1). The number of micronuclei in haemocytes also increased with the time after pyrene inoculation, indicating that exposure to pyrene triggers genotoxic and mutagenic response. In crabs from a heavily oil-contaminated mangrove pyrene-1-glucoside was the major metabolite, an indication that production/excretion of a certain metabolite varies depending on adaptation of the animal to the environment. A highly significant correlation was found between the concentration of pyrene metabolites in urine of field crabs expressed as OH-pyrene equivalents and the sum of 38 PAHs determined in hepatopancreas/sediments (r=0.825, n=23, p<0.05). The response of these crabs to the micronuclei assay was not significantly related to concentration of individual or total PAHs. Nevertheless, metabolite results prove U. cordatus as excellent bioindicator for evaluating environmental quality in mangrove areas as related to PAHs and oil contamination.