Ongoing Laboratory Performance Study on Chemical Analysis of Hydrophobic and Hydrophilic Compounds in Three Aquatic Passive Samplers

The quality of chemical analysis is an important aspect of passive sampling-based environmental assessments. The present study reports on a proficiency testing program for the chemical analysis of hydrophobic organic compounds in silicone and low-density polyethylene (LDPE) passive samplers and hydrophilic compounds in polar organic chemical integrative samplers. The median between-laboratory coefficients of variation (CVs) of hydrophobic compound concentrations in the polymer phase were 33% (silicone) and 38% (LDPE), similar to the CVs obtained in four earlier rounds of this program. The median CV over all rounds was 32%. Much higher variabilities were observed for hydrophilic compound concentrations in the sorbent: 50% for the untransformed data and a factor of 1.6 after log transformation. Limiting the data to the best performing laboratories did not result in less variability. Data quality for hydrophilic compounds was only weakly related to the use of structurally identical internal standards and was unrelated to the choice of extraction solvent and extraction time. Standard deviations of the aqueous concentration estimates for hydrophobic compound sampling by the best performing laboratories were 0.21 log units for silicone and 0.27 log units for LDPE (factors of 1.6 to 1.9). The implications are that proficiency testing programs may give more realistic estimates of uncertainties in chemical analysis than within-laboratory quality control programs and that these high uncertainties should be taken into account in environmental assessments

1-Hydroxypyrene–A Biochemical Marker for PAH Pollution Assessment of Aquatic Ecosystem

The aim of the present study was to assess aquatic contamination by polycyclic aromatic hydrocarbons (PAH), using the 1-hydroxypyrene (1-OHP) content in fish bile as a biochemical marker. A total of 71 chub (Leuciscus cephalus L.) were collected from seven locations on the Svitava and Svratka rivers in and around the industrial city of Brno, Czech Republic. The levels of 1-OHP were determined by reverse phase HPLC with fluorescence detection after deconjugation. Normalising the molar concentration of the biliary 1-OHP to the biliary protein content reduced sample variation. The content of 1-OHP was correlated with the PAH level in bottom sediment and semi-permeable membrane devices (SPMD), which was analyzed by a combination of HPLC/FLD and GC/MS methods. The highest mean values of 1-OHP were found in fish caught at the Svratka River at locations Modřice (169.2 ± 99.7 ng·mg−1 protein) and Rajhradice (152.2 ± 79.7 ng·mg−1 protein), which are located downstream from Brno. These values were significantly (P < 0.05) higher than those obtained from localities Kníničky (98.4 ± 66.1 ng·mg−1 protein) and Bílovice nad Svitavou (64.1 ± 31.4 ng·mg−1 protein). The lowest contents of PAH in sediment and SPMD were found at location Kníničky (1.5 mg·kg−1 dry mass and 19.4 ng·L−1, respectively). The highest contents of PAH in sediment and SPMD were found in Rajhradice (26.0 mg·kg−1 dry mass) and Svitava before junction (65.4 ng·L−1), respectively. A Spearman correlation test was applied to determine the relationship between biliary 1-OHP and the sum of PAH in sediment and SPMD. A positive, but no statistically significant correlation was found. The main impact sources of elevated level of PAHs in sites located downstream from Brno are most probably intensive industrial and agricultural activities and domestic waste

An interlaboratory study on passive sampling of emerging water pollutants

An inter-laboratory study was organised for the monitoring of emerging aquatic pollutants (pharmaceuticals, pesticides, steroids, brominated diphenyl ethers and others) using passive samplers. Thirty laboratories participated in the sampler comparison exercise. Various samplers designs were exposed at a single sampling site to treated waste water. The organisers deployed in parallel multiple samplers of a single type, which were distributed for evaluation of the contribution of the different analytical procedures to the data variability. Between laboratory variation of results from passive samplers was about factor 5 larger than within laboratory variability. Similar results obtained for different passive samplers analysed by individual laboratories and also low within laboratory variability indicate that the passive sampling process is causing less variability than the analysis. Concentrations in composite water samples were within the range obtained by passive samplers. In future a significant improvement of analytical precision and calibration of adsorption based passive samplers is needed.JRC.H.1-Water Resource