Comprehensive analytical strategy for biomonitoring of pesticides in urine by liquid chromatography­orbitrap high resolution masss pectrometry.

In this study we propose an analytical strategy that combines a target approach for the quantitative analysis of contemporary pesticide metabolites with a comprehensive post-target screening for the identification of biomarkers of exposure to environmental contaminants in urine using liquid chromatography coupled to high-resolution mass spectrometry (LC­HRMS). The quantitative method for the target analysis of 29 urinary metabolites of organophosphate (OP) insecticides, synthetic pyrethroids, herbicides and fungicides was validated after a previous statistical optimization of the main factors governing the ion source ionization and a fragmentation study using the high energy collision dissociation (HCD) cell. The full scan accurate mass data were acquired with a resolving power of 50,000 FWHM (scan speed, 2 Hz), in both ESI+ and ESI− modes, and with and without HCD-fragmentation. The method ­ LOQ was lower than 3.2 µg L−1 for the majority of the analytes. For post-target screening a customized theoretical database was built, for the identification of 60 metabolites including pesticides, PAHs, phenols, and other metabolites of environmental pollutants. For identification purposes, accurate exact mass with less than 5 ppm, and diagnostic ions including isotopes and/or fragments were used. The analytical strategy was applied to 20 urine sample collected from children living in Valencia Region. Eleven target metabolites were detected with concentrations ranging from 1.18 to 131 µg L−1. Likewise, several compounds were tentatively identified in the post-target analysis belonging to the families of phthalates, phenols and parabenes. The proposed strategy is suitable for the determination of target pesticide biomarkers in urine in the framework of biomonitoring studies, and appropriate for the identification of other non-target metabolites.

Sampling and analysis of pesticides in ambient air.

Developments in the sampling and determination of pesticides in ambient air have been discussed and data on the occurrence of pesticides in atmosphere have been presented. Developments in active sampling methods were reviewed and the different materials used for trapping pesticides from gas and particulate phases were discussed. Likewise, the use and developments of passive air samplers were reviewed. This article pays special attention to the analysis of pesticides trapped from ambient air, and recapitulate the procedures for extraction, clean-up and determination of these substances. Improvements in sampling procedures, analytical methods and monitoring activities are necessary to advance the knowledge of occurrence of currently used pesticides in atmosphere and their impact over environment and humans.

Monitoring programme on cadmium, lead and mercury in fish and seafood from Valencia, Spain: levels and estimated weekly intake.

The study was carried out to determine the current levels of mercury, cadmium, and lead in fish and seafood from the market of Comunitat Valenciana, Spain. Levels of total mercury ranged from 0.02 to 3.15 mg kg⁻¹ w.w. (average = 0.073 mg kg⁻¹ w.w.). Cadmium concentrations ranged from 0.003 to 0.66 mg kg⁻¹ w.w. (average = 0.27 mg kg⁻¹ w.w.) for seafood, and between 0.003 and 0.71 mg kg⁻¹ w.w. (average = 0.01 mg kg⁻¹ w.w.) for marine fish. Concerning lead, concentrations from 0.02 to 0.36 mg kg⁻¹ w.w (average = 0.04 mg kg⁻¹ w.w.) were found in fish, and from 0.02 to 1.02 mg kg⁻¹ w.w. in seafood (average = 0.147 mg kg⁻¹ w.w.). The levels found were, in general, lower than maximum levels proposed by European legislation. The estimated weekly intake of mercury, cadmium and lead through fish and seafood consumption was found to be about 43%, 10% and 3% of the established provisional tolerable weekly intake, respectively.

Determination of PAHs in airborne particles by accelerated solvent extraction and large-volume injection-gas chromatography-mass spectrometry.

A sensitive and automated method is presented for the determination of polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter. The procedure includes extraction of PM10-bound PAHs by accelerated solvent extraction (ASE) followed by gel permeation chromatography (GPC) clean-up, and large-volume programmable temperature vaporizer (PTV-LV) injection coupled to GC-MS. The limit of detection (LOD) of the whole method, based on a signal-to-noise ratio (S/N) of 3:1, ranged from 0.26pgm(-3) to 3pgm(-3) when air volumes of 760m(3) are collected. The hexane-acetone mixture (1:1, v/v) gave the best recoveries when ASE parameters were fixed at 125 degrees C, 1500psi, and a total time of 10min. The recoveries for all PAHs tested ranged from 96% to 103%, rates similar to those obtained by the Soxhlet reference method. To improve the sensitivity, 70muL were injected. The PTV-LV injection settings were optimized using a statistical design of experiments, including a screening 2(4) full factorial design and a further central composite design. A sensitivity increase from 10 to 50 times was achieved as compared with the conventional 2muL splitless injection. The method was validated with the standard reference material SRM 1649a and applied to real PM10 samples from the monitoring network of the Regional Valencia Government (Spain). The analytical performance of the method shows that it is appropriate to monitor PAHs levels in ambient air according to European Union Directives. In addition, the method can be used when a high sensitivity is required.