Concentration and derivatization in silicone rubber traps for mass spectrometric and gas chromatographic analysis of air and water pollutants

Estrogens, alkylphenols and bisphenol-A, enter the environment through waste water systems and waste disposal of manufactured products e.g. detergents, paints, polycarbonates and flameretardants. These analytes disrupt the endocrine function of living organisms affecting their reproductive health and those of future generations. Gas phase low molecular- mass aldehydes and amines are typically eye, nose, and throat irritants. Formaldehyde is classified as a probable human carcinogen. Given their negative impact on human health it is urgent to monitor pollutants at extremely low levels in both air and water. The aqueous pollutants are often concentrated using solid phase extraction cartridges or liquid-liquid extraction followed by derivatization. Methods that can most effectively and selectively pre-concentrate aldehydes and amines involve in situ derivatization. Unfortunately, the derivatizing reagents as well as their associated solvents or adsorbents, are responsible for problems encountered with these methods. Polydimethylsiloxane (PDMS) has emerged as the ideal concentration and reaction medium for trace analysis. However the expensive commercial devices such as SPME and SBSE both require the samples to be returned to the laboratory for concentration. Due to the open tubular nature of the PDMS multichannel trap (MCT), developed in our laboratory, it is ideally suited for on-site and online sampling. The MCTs have a high analyte capacity owing to the large volume of PDMS available for concentration. The derivatization reaction can be performed in situ providing a “onepot concentration and reaction device”. This allows for reduced risk of contamination of / or losses of the sample and a sampling method that can cater for both air and water samples. To demonstrate the versatility of the PDMS MCT, two approaches for concentration in PDMS were investigated in this study, namely, 1) the on-line concentration and in situ derivatization of volatile polar analytes from air followed by REMPI-TOFMS detection, and 2) the concentration of phenolic lipophilic analytes from water requiring derivatization prior to analysis by GC/MS. 1) Analyte and derivatizing reagent were simultaneously introduced into the PDMS trap using a ypress- fit connector. The reaction occurs in situ followed by thermal desorption using a thermal modulator array alone or in conjunction with a thermal desorption unit. The aldehydes and amine derivatives were successfully detected by the REMPI-TOFMS. Reaction efficiencies were determined at room temperature without catalysts. Formaldehyde yielded a low reaction/concentration efficiency of 41 % with phenylhydrazine in PDMS, while acetaldehyde, acrolein and crotonal displayed much improved values of 92, 61 and 74 % respectively. Both propylamine and butylamine yielded 28 % reaction/concentration efficiency with benzaldehyde in the PDMS matrix. Detection limits obtained with this technique were significantly lower than the permissible exposure limits set by the Occupational Safety and Health Administration. It should be noted that the detection limits were not determined by actual measurement but by extrapolation from a larger signal. 2) Aqueous analytes were concentrated in the PDMS MCT using a gravity flow rate of ~50 ìl/min. The trap was dried and 5 ìl derivatizing reagent added. At room temperature and without the presence of a catalyst, the reaction of alkylphenols with trifluoroacetic acid anhydride in the PDMS matrix was 100% complete after 5 minutes. Bisphenol-A reacted less than 50 % to completion during this period, but the amount of derivative formed remained constant. This study revealed that extraction efficiencies of the alkylphenols and bisphenol-A off the PDMS trap have poor batch-tobatch repeatability indicating that the PDMS matrix was not homogenous. For two different PDMS batches: tert-octylphenol displayed an extraction efficiency of 70 and 79%, nonylphenol displayed 84 and 43% while Bisphenol-A displayed 10 and 26% respectively. The thermally desorbed derivatives were analysed by GC/MS. Despite background contamination in the desorption unit, detection limits were at the ppt level. Detection limits were not determined by actual measurement but by extrapolation from a larger signal.Thesis (PhD)--University of Pretoria, 2009.Chemistryunrestricte

Cooperation in publicly funded reference material production

The meeting was organized by the European Commission's Joint Research Centre, and held at the JRC-Geel site on 22-23 February, 2018. It was a follow-up of a similar meeting held in 2009. The objective of the meeting was to exchange information about ongoing publicly funded reference material (RM) production, identify areas of interest for future specific RMs, including Certified Reference Material (CRM) developments, investigate potential areas of collaboration, and to identify areas which may be of a lower importance in the future for a specific RM-producer. The benefit of exchanging such information is to avoid duplication of efforts in RM production, make better use of public funds by potentially matching competencies, and to address problems that are common to publicly funded RM-producers. Attendees included representatives of the following organisations: Bundesanstalt für Materialforschung und –prüfung (BAM), Germany; IAEA Environment Laboratories , Monaco; the Joint Research Centre (JRC), Belgium (formerly IRMM); the Korea Research Institute of Standards and Science (KRISS), South Korea; LGC, United Kingdom, the National Institute for Standards and Technology (NIST), USA; the National Measurement Institute of Australia (NMIA), Australia; the National Metrology Institute of South Africa (NMISA), South Africa; and the National Research Council Canada (NRCC), Canada. Attendees participated physically or via videoconference. In preparation for the meeting, each participating organisation provided a list of current and planned projects. During the meeting itself, each institution presented its main fields of activity and offered additional information on its RM programme as required. Discussions not only addressed detailed technical questions but also dealt with questions on policy and legal status. Additional meetings like this can help to assist in the overall prioritisation of RM production internationally. This meeting report discusses the drivers and approaches taken by publicly funded RM-producers, and analyses the areas of RM development currently being covered. A view of current areas of activity of the publicly funded RM-producers is provided and a summary of some future trends is given.JRC.F.6-Reference Material

O cuidar de crianças portadoras de bexiga neurogênica: representações sociais das necessidades dessas crianças e suas mães El cuidar niños portadores de vejiga neurogenica: representaciones sociales de las necesidades de esos niños y sus madres Caring for children with neurogenic blader dysfunction: social representation of these children's and their mothers' needs

Esta investigação buscou conhecer e analisar as representações e necessidades de crianças em idade escolar, portadoras de bexiga neurogênica, e de suas mães. A pesquisa foi de natureza qualitativa, sendo as representações sociais o processo metodológico adotado. Na interposição das categorias empíricas com as analíticas, o viver e o cuidar são representados respectivamente pelas mães como um "problema" e "tudo eu"; as crianças, por sua vez, interpretam com "num é justo" a interação diferenciada e preconceituosa que sofrem no contexto em que estão inseridas.<br>Esta investigación busca conocer y analizar las representaciones y necesidades de niños en edad escolar, portadores de vejiga neurogénica y sus madres. Investigación de naturaleza cualitativa, siendo las representaciones sociales el proceso metodológico adoptado. La interposición de las categorías empíricas con las analíticas, el vivir y el cuidar son representados respectivamente por las madres como un "problema" y "todo yo"; los niños, a su vez, interpretan como "no es justa" la interacción diferenciada y con preconceptos que sufren en el contexto en el cual estos niños se desenvuelven cotidianamente.<br>The purpose of this study was to know and analyze the representations and needs of school-age children with neurogenic bladder dysfunction and of their mothers. This is a qualitative study; whose methodology was based on social representations. According to the interposition of empirical end analytical categories, the living and caring are respectively represented by mothers as "a problem" and "all me"; the children, in turn, interpret the differentiated and prejudiced interaction they suffer in the setting they live in as "it is not fair"

CCQM-K102 Polybrominated diphenyl ethers in sediment

The key comparison CCQM-K102: Polybrominated diphenyl ethers in sediment was coordinated by the JRC, Directorate F – Health, Consumers & Reference Materials, Geel (Belgium) under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM). Thirtheen National Metrology institutes or Designated Institutes and the JRC participated. Participants were requested to report the mass fraction (on a dry mass basis) of BDE 47, 99 and 153 in the freshwater sediment study material. The sediment originated from a river in Belgium and contained PBDEs (and other pollutants) at levels commonly found in environmental samples. The comparison was designed to demonstrate participants' capability of analysing non-polar organic molecules in abiotic dried matrices (approximate range of molecular weights: 100 to 800 g/mol, polarity corresponding to pKow < -2, range of mass fraction: 1-1000 µg/kg). All participants (except one using ultrasonic extraction) applied Pressurised Liquid Extraction or Soxhlet, while the instrumental analysis was performed with GC-MS/MS, GC-MS or GC-HRMS. Isotope Dilution Mass Spectrometry approach was used for quantification (except in one case). The assigned Key Comparison Reference Values (KCRVs) were the medians of thirteen results for BDE 47 and eleven results for BDE 99 and 153, respectively. BDE 47 was assigned a KCRV of 15.60 µg/kg with a combined standard uncertainty of 0.41 µg/kg, BDE 99 was assigned a KCRV of 33.69 µg/kg with a combined standard uncertainty of 0.81 µg/kg and BDE 153 was assigned a KCRV of 6.28 µg/kg with a combined standard uncertainty of 0.28 µg/kg. The k-factor for the estimation of the expanded uncertainty of the KCRVs was chosen as k = 2. The degree of equivalence (with the KCRV) and its uncertainty were calculated for each result. Most of the participants to CCQM-K102 were able to demonstrate or confirm their capabilities in the analysis of non-polar organic molecules in abiotic dried matrices. Throughout the study it became clear that matrix interferences can influence the accurate quantification of the PBDEs, if the analytical methodology applied is not appropriately adapted and optimised. This comparison shows that quantification of PBDEs at the µg/kg low-middle range in a challenging environmental abiotic dried matrix can be achieved with relative expanded uncertainties below 15 % (more than 70 % of participating laboratories), well in line with the best measurement performances in the environmental analysis field.JRC.F.6-Reference Material