A robust procedure for the determination of 16 US EPA PAHs in both aqueous (e.g. wastewaters, industrial discharges, treated effluents) and solid samples (e.g. suspended solids and sludge) from a wastewater treatment plant (WWTP) is presented. Recovery experiments using different percentages of organic modifier, sorbents and eluting solvent mixtures were carried out in Milli-Q water (1000 mL) spiked with a mixture of the PAH analytes (100 ng/L of each analyte). The solid phase extraction (SPE) procedures applied to spiked waste water samples (1000 mL; 100 ng/L spiking level) permitted simultaneous recovery of all the 16PAHs with yields >70% (6-13% RSD). SPE clean up procedures applied to sewage and stabilized sludge extracts, showed percent recoveries in the range 73-92% (7-13% RSD) and 71-89% (7-12% RSD), respectively. The methods were used for the determination of PAHs in aqueous and solid samples from the WWTP of Fusina (Venice, Italy). Mean concentrations, as the sum of the 16PAHs in aqueous and suspended solid samples, were found to be approx. in the 1.12-4.62 microg/L range. Sewage and stabilized sludge samples contained mean PAH concentrations, as sum of 16 compounds, in the concentration range of 1.44-1.26 mg/kg, respectively. Extraction and clean up procedures for sludge samples were validated using EPA certified reference material IRM-104 (CRM No. 912). Instrumental analyses were performed by coupling HPLC with UV-diode array detection (UV-DAD) and fluorescence detection (FLD).

Removal of organic micropollutants from wastewater during secondary treatment followed by reverse osmosis and UV disinfection was evaluated by a combination of four in-vitro cell-based bioassays and chemical analysis of 299 organic compounds. Concentrations detected in recycled water were below the Australian Guidelines for Water Recycling. Thus the detected chemicals were considered not to pose any health risk. The detected pesticides in the wastewater treatment plant effluent and partially advanced treated water explained all observed effects on photosynthesis inhibition. In contrast, mixture toxicity experiments with designed mixtures containing all detected chemicals at their measured concentrations demonstrated that the known chemicals explained less than 3% of the observed cytotoxicity and less than 1% of the oxidative stress response. Pesticides followed by pharmaceuticals and personal care products dominated the observed mixture effects. The detected chemicals were not related to the observed genotoxicity. The large proportion of unknown toxicity calls for effect monitoring complementary to chemical monitoring.

Chlorination of amino acids can result in the formation of organic monochloramines or organic dichloramines, depending on the chlorine to amino acid ratio (Cl:AA). After formation, organic chloramines degrade into aldehydes, nitriles and N-chloraldimines. In this paper, the formation of organic chloramines from chlorination of lysine, tyrosine and valine were investigated. Chlorination of tyrosine and lysine demonstrated that the presence of a reactive secondary group can increase the Cl:AA ratio required for the formation of N,N-dichloramines, and potentially alter the reaction pathways between chlorine and amino acids, resulting in the formation of unexpected byproducts. In a detailed investigation, we report rate constants for all reactions in the chlorination of valine, for the first time, using experimental results and modeling. At Cl:AA = 2.8, the chlorine was found to first react quickly with valine (5.4 × 10 M s) to form N-monochlorovaline, with a slower subsequent reaction with N-monochlorovaline to form N,N-dichlorovaline (4.9 × 10 M s), although some N-monochlorovaline degraded into isobutyraldehyde (1.0 × 10 s). The N,N-dichlorovaline then competitively degraded into isobutyronitrile (1.3 × 10 s) and N-chloroisobutyraldimine (1.2 × 10 s). In conventional drinking water disinfection, N-chloroisobutyraldimine can potentially be formed in concentrations higher than its odor threshold concentration, resulting in aesthetic challenges and an unknown health risk.

Although organic chloramines are known to form during the disinfection of drinking water with chlorine, little information is currently available on their occurrence or toxicity. In a recent in vitro study, some organic chloramines (e.g. N-chloroglycine) were found to be cytotoxic and genotoxic even at micromolar concentrations. In this paper, the formation and stability of 21 different organic chloramines, from chlorination of simple amines and amino acids, were studied, and the competition between 20 amino acids during chlorination was also investigated. For comparison, chlorination of two amides was also conducted. The formation and degradation of selected organic chloramines were measured using either direct UV spectroscopic or colorimetric detection. Although cysteine, methionine and tryptophan were the most reactive amino acids towards chlorination, they did not form organic chloramines at the chlorine to precursor molar ratios that were tested. Only 6 out of the 21 organic chloramines formed had a half-life of more than 3 h, although this group included all organic chloramines formed from amines. A health risk assessment relating stability and reactivity data from this study to toxicity and precursor abundance data from the literature indicated that only N-chloroglycine is likely to be of concern due to its stability, toxicity and abundance in water. However, given the stability of organic chloramines formed from amines, more information about the toxicity and precursor abundance for these chloramines is desirable.

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The iodinated X-ray contrast media are the most widely administered intravascular pharmaceuticals and are known to persist in the aquatic environment. A rapid method using direct injection liquid chromatography-tandem mass spectrometry (DI-LC-MS/MS) has been developed to measure eight ICM. These include iopamidol, iothalamic acid, diatrizoic acid, iohexol, iomeprol, iopromide, plus both ioxaglic acid and iodipamide, which have not previously reported in the literature. The LC-MS/MS fragmentation patterns obtained for each of the compounds are discussed and the fragments lost for each transition are identified. Matrix effects in post-RO water, MQ water, tap water and secondary effluent have also been investigated. The DI-LC-MS/MS method was validated on both secondary and tertiary treated wastewater, and applied to samples from an advanced activated sludge wastewater treatment plant (WWTP) and a water recycling facility using microfiltration (MF) and reverse osmosis (RO) in Perth, Western Australia. As well as providing information of the efficacy for RO to remove specific ICM, these results also represent the first values of ICM published in the literature for Australia.

The exposure of the Venice lagoon (Italy) to endocrine-disrupting compounds (EDCs) from different sources was investigated. Spatial and time distribution of EDC concentrations were determined in four sampling sessions (December 2001-May 2002) by solid phase extraction followed by high-performance liquid chromatography separation coupled with mass spectrometry detection via electrospray interface (SPE-HPLC-ESI-MS), which allowed identification of natural (estradiol, estrone) and synthetic estrogenic compounds, both steroidal (ethinylestradiol, mestranol) and nonsteroidal (benzophenone, bisphenol-A, nonylphenol, nonylphenol monoethoxylate carboxylate). No significant differences in the EDC distribution were observed between stations located near selected sources (raw sewage from the historical center of Venice, treated municipal and industrial effluents from sewage treatment plants, and areas undergoing the inflow of rivers). While synthetic nonsteroidal analytes were recorded in the 1 to 1040 ng/L range (average concentration: 34 ng/L), steroidal EDC (estradiol, ethinylestradiol) concentrations were lower (1-125 ng/L; average concentration: 8 ng/L). The estrogenic activity of lagoon waters was estimated in terms of estradiol equivalent concentration (EEQ) by applying the estradiol equivalency factors (EEFs). Steroidal EDCs (estradiol, ethinylestradiol) contributed >97% to the total potential estrogenicity of the waters, which accounted for 4 to 172 ng/L (average: 25 ng/L), as total EEQs. These levels are likely to pose adverse effects on the Venice lagoon aquatic organisms.

Milk proteins including casein are sources of peptides with bioactivity. One of these peptides is beta-casomorphin (BCM) which belongs to a group of opioid peptides formed from b-casein variants. Beta-casomorphin 7 (BCM7) has been demonstrated to be enzymatically released from the A1 or B b-casein variant. Epidemiological evidence suggests the peptide BCM 7 is a risk factor for development of human diseases, including increased risk of type 1 diabetes and cardiovascular diseases but this has not been thoroughly substantiated by research studies. High performance liquid chromatography coupled to UV-Vis and mass spectrometry detection as well as enzyme-linked immunosorbent assay (ELISA) has been used to analyze BCMs in dairy products. BCMs have been detected in raw cow's milk and human milk and a variety of commercial cheeses, but their presence has yet to be confirmed in commercial yoghurts. The finding that BCMs are present in cheese suggests they could also form in yoghurt, but be degraded during yoghurt processing. Whether BCMs do form in yoghurt and the amount of BCM forming or degrading at different processing steps needs further investigation and possibly will depend on the heat treatment and fermentation process used, but it remains an intriguing unknown.