Silicon dioxide and titanium dioxide particles found in human tissues.

Silicon dioxide (silica, SiO, SAS) and titanium dioxide (TiO) are produced in high volumes and applied in many consumer and food products. As a consequence, there is a potential human exposure and subsequent systemic uptake of these particles. In this study we show the characterization and quantification of both total silicon (Si) and titanium (Ti), and particulate SiO and TiO in postmortem tissue samples from 15 deceased persons.

Brominated flame retardants in animal derived foods in the Netherlands between 2009 and 2014.

Polybrominated diphenylethers (PBDEs), hexabromocyclododecanes (HBCDDs) and tetrabromobisphenol A (TBBPA) were monitored in various foods from terrestrial and aquatic animal origin (>850 samples), collected in the Netherlands between 2009 and 2014. The terrestrial samples included meat/fat from 7 animal species (including bovines, pigs, broilers and sheep), bovine milk and hen eggs. Dominant PBDE congeners in these samples were BDE-47, -99, -100, -153 and -183.

Blood and urine analyses after radioembolization of liver malignancies with [Ho]Ho-acetylacetonate-poly(l-lactic acid) microspheres.

Background: [Ho]Ho-acetylacetonate-poly(L-lactic acid) microspheres were used in radioembolization of liver malignancies by intra-arterial administration. The primary aim of this study was to assess the stability and biodistribution of these microspheres.

Materials And Methods: Peripheral blood and urine samples were obtained from two clinical studies.

Detection of nanoparticles in Dutch surface waters.

Nano-enabled consumer products are a likely source of nanoparticles in the environment and a number of studies have shown the release of nanoparticles from commercial products. Predicted environmental concentrations have been calculated but there is a need for real measurement data to validate these calculations. However, the detection of engineered nanoparticles in environmental matrices is challenging because of the low predicted environmental concentrations which may be in the ng/L range.

Dioxins, PCBs and heavy metals in Chinese mitten crabs from Dutch rivers and lakes.

Chinese mitten crab is an invasive species in many European rivers and lakes. Data from the UK indicated high levels of dioxins and PCBs, in particular in the brown meat in the body. This was confirmed by studies in the Netherlands, showing average levels of dioxins and PCBs in the meat in the body of 43 pg TEQ g(-1) ww in crabs caught in the large rivers.

metAlignID: a high-throughput software tool set for automated detection of trace level contaminants in comprehensive LECO two-dimensional gas chromatography time-of-flight mass spectrometry data.

A new alternative data processing tool set, metAlignID, is developed for automated pre-processing and library-based identification and concentration estimation of target compounds after analysis by comprehensive two-dimensional gas chromatography with mass spectrometric detection. The tool set has been developed for and tested on LECO data. The software is developed to run multi-threaded (one thread per processor core) on a standard PC (personal computer) under different operating systems and is as such capable of processing multiple data sets simultaneously.

Simultaneous extraction and determination of HBCD isomers and TBBPA by ASE and LC-MSMS in fish.

Since the EFSA enquired a call for data for TBBPA and HBCD in 2009, the analytical determination of these compounds in food became of regulatory interest. Therefore, a method for the simultaneous determination of TBBPA and the three major HBCD stereoisomers was developed. Conventional techniques like soxhlet, ASE, GPC, sulphuric acid digestion, and acidified silica SPE are generally used in sample pre-treatment while detection is mostly performed by LC-MSMS.

Validation of automated library-based qualitative screening of pesticides by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry.

A method for automated detection and reporting of pesticides in plant materials based on comprehensive two-dimensional GC/time-of-flight MS with library-based detection by software has been developed and validated. Optimum settings for detection parameters such as spectral match threshold and first and second dimension retention time tolerances were assessed with respect to occurrence of false detects and false negatives. Next the method was validated following European Union guidelines established for qualitative screening of pesticides.

Levels of PCDD/Fs, PCBs and PBDEs in butter from Turkey and estimated dietary intake from dairy products.

Polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs), dioxin-like and non-dioxin-like (indicator) polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) were monitored in butterfat obtained from 18 different areas in Turkey, both rural and industrial. The results obtained both at RIKILT in the Netherlands and in a food control laboratory in Turkey for PCDD/Fs and PCBs were in good agreement. The sum of PCDD/Fs+dl-PCBs, total indicator PCBs and PBDEs were in the range 0.

Qualitative screening and quantitative determination of pesticides and contaminants in animal feed using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry.

A method has been developed for the target analysis of over 100 pesticides and contaminants in a complex feed matrix. The method is based on extraction with ethyl acetate, cleanup by gel permeation chromatography (GPC) and dispersive solid-phase extraction (SPE) with primary secondary amine phase (PSA), and analysis by comprehensive two-dimensional gas chromatography with full scan time-of-flight mass spectrometric detection (GC x GC-TOF-MS). Parameters studied during method development included a dispersive SPE cleanup step after GPC, large volume injection into the GC system and the GC x GC separation.

Deposition precipitation for the preparation of carbon nanofiber supported nickel catalysts.

Deposition precipitation of nickel hydroxide onto modified carbon nanofibers has been studied and compared to deposition onto silica. The carbon nanofiber support materials consisted of graphite-like material of the fishbone-type with a diameter of 20-50 nm and a specific surface area of 150 m2/g. Modification involved surface oxidation (CNF-O) optionally followed by partial reduction (CNF-OR) or thermal treatment (CNF-OT).