A fit-for-purpose method to monitor 16 European Union PAHs in food: results of five years of official food control in two Italian regions.

A gas-chromatographic single-quadrupole analytical method for the analysis of the 16 priority European Union (EU) polycyclic aromatic hydrocarbons (PAHs) in food is presented. The method fulfils the request of Regulation EU 836/2011 for an analytical procedure to be used for official control of PAHs in food in EU member states. The sample preparation involves a pressurised liquid extraction (PLE) with an in-cell clean-up step followed by a lipid removal using solid-phase extraction (SPE) on a styrene divinylbenzene stationary phase (SDVB) and a final gel-permeation chromatography (GPC) step. To reach a better sensitivity for all the analytes, including the heaviest last eluting PAHs, 3 µl of the purified extract were injected in solvent vent mode using a programmable temperature vaporization (PTV) injector. The isobaric PAH isomers were successfully separated using an Agilent Technologies DB-17MS (20 m × 0.18 mm × 0.18 µm) column. The method was fully validated using an in-house approach and the sensitivity, accuracy and precision obtained were satisfactory. The method expanded uncertainty was estimated and it was verified that it was below the maximum standard measurement uncertainty. Moreover, the results of 347 samples of meat and meat products, fish and fish products and mussels collected from January 2012 to December 2016 in the Marche and Umbria regions of Italy are reported. None of the samples exceed the maximum levels fixed by EU Regulation 835/2011, and clams turned out to be the most contaminated among the food matrices analysed. Finally, an estimate of the sum of four marker PAHs (benzo[a]anthracene, benzo[b]fluoranthene, benzo[a]pyrene, chrysene) as indicator of the PAHs contamination was done by comparison with the 16 carcinogenic PAHs sum.

Polybrominated diphenyl ethers in mussels (Mytilus galloprovincialis) collected from Central Adriatic Sea.

One-hundred and thirty-four samples of mussels (Mytilus galloprovincialis) collected along Central Adriatic Sea in 2013 were examined to determine the levels of fifteen congeners of polybrominated diphenyl ethers (PBDEs). The purified samples were analysed by gas-chromatography coupled to tandem mass spectrometry (GC-MS/MS) applying the isotopic dilution. Only four congeners (PBDE 47, PBDE 99, PBDE 49 and PBDE 100) were present above the established limits of quantification with mean concentrations equal to 73, 30, 19 and 18 pg g(-1), respectively. The concentrations of PBDEs (sum) ranged from 27 to 386 pg g(-1), with the highest levels around the coastal area of Ancona town. The here found levels were comparable to those measured in mussels collected along Southern Adriatic Sea.

High-throughput histamine analysis approach in an official control laboratory: analytical methods and four years fish products results.

A highly practical two-tier approach involving a screening and a confirmatory method was set up to efficiently test histamine in fish products in the frame of official controls. After their validation, the routine management of the two procedures was simplified as far as possible ensuring a strict quality data control and maximizing the cost-effectiveness. Accordingly five hundred and ninety batches of fish products (3129 determinations) sampled from the Italian authorities were successfully analyzed over a four year period (2008-2012). Only a small percentage of analysed batches (4.9%) was judged non-compliant. The examination of irregular cases (fish species, processing technology and storage practices) suggests important considerations in order to minimise the histamine risk for consumers.

Temporal trends of PCBs in feed and dietary influence in farmed rainbow trout (Oncorhynchus mykiss).

As a rainbow trout producer, Italy is accounted as fifth in the world and second in continental Europe. In this study, the levels of the eighteen PCBs in feed and in trout, showed a statistical significant difference (p<0.01) throughout the years, with a declining trend from 2005 to 2010. This trend shows effectively that quality and safety of trout feeds has greatly improved during the last years and, as a consequence, also the PCBs values in muscle trout, showed a decreasing trend. Moreover, feed Σ18PCBs showed a statistical significant difference (p<0.01) among the analysed brands and was positively correlated (p<0.01 and r=0.451) with the rainbow trout muscle Σ18PCBs. These results showed that the presence of PCBs in trout muscle is directly linked to the chemical quality of aquaculture feed. The most commonly detected PCBs congeners were congeners PCB 153 and PCB 138 in all the three compared brands.

PCB concentrations in freshwater wild brown trouts (Salmo trutta trutta L) from Marche rivers, Central Italy.

The purpose of this study is to evaluate the degree of PCBs contamination of wild brown trouts (Salmo trutta trutta L) caught in Marche Region rivers and to study the percentage contribution of the sum of the six indicators PCBs with respect to the sum of eighteen congeners in wild brown trouts. The determination of eighteen PCBs was made on the edible portion (fillets) of trouts by GC-ECD analysis. Fish samples were collected from fourteen rivers, selected to represent the fluvial pollution in the Marche Region. The total sum of eighteen congener concentrations was 8.2±0.9 ng/g wet weight. All the analysed samples showed a high variability of their congener profile even though the six PCBs indicators stood for 49.8% of the total PCBs. In the muscle of brown trout the Σ eighteen PCB and the Σ six PCB concentrations were not statistically correlated with the length and the body mass of specimens. Total PCB (Σ eighteen PCBs and Σ six PCBs) concentrations measured in the different sampling sites showed significant statistical differences among districts and, in the same district, among rivers (p<0.01). In particular, the lowest PCB levels (p<0.01) were detected in fish caught in Pesaro-Urbino Province rivers with the mean total PCB concentrations of 102.4±6.3 ng/g fat weight while the highest PCB levels were measured in specimens coming from Macerata Province rivers (1147.8±456.6 ng/g fat weight).

LC-MS determination of MPTP at sub-ppm level in pethidine hydrochloride.

An HPLC-MS with electrospray ionisation method for the determination of MPTP at sub-ppm level in pethidine hydrochloride has been developed and validated. Ionisation is performed by positive-ion electrospray and the quadrupole filter mass spectrometer is operated in the single ion recording mode. Chromatographic separation was achieved in gradient elution using a symmetry C18, 5 microm, 150 mm x 2.1 mm i.d. The mobile phase comprised water containing 0.1% formic acid (v/v) and acetonitrile containing 0.1% formic acid (v/v). The method showed to be linear in the range between 0.2 and 2.2 ng/ml, the estimated LOD was lower than 0.1 ng/ml and the LOQ was lower than 0.2 ng/ml.

Influence of aeration and sludge retention time on ammonium oxidation to nitrite and nitrate.

Partial nitrification to nitrite was reported to be technically feasible and economically favourable, especially when wastewater with high ammonium concentrations or low C/N ratios are treated. Nitritation can be obtained by selectively inhibiting nitrite oxidizing microrganisms through appropriate regulation of the system's pH, temperature, and sludge retention time. In addition to already known methods, the work showed that aeration patterns may play a relevant role too. Nitrification tests were performed in two lab-scale reactors operated under continuous and intermittent aeration, respectively. In both plants, temperature was maintained at 32 degrees C and pH was regulated at 7.2 by providing external buffer capacity when needed. The results showed that partial nitrification to nitrite was steadily obtained under oxygen limitation, independent of the sludge age. Therefore, the aeration pattern is proposed as an alternative parameter to the sludge retention time for controlling ammonium oxidation to nitrite.