TY - JOUR A1 - Becker, Roland A1 - Buge, Hans-Gerhard A1 - Bremser, Wolfram A1 - Nehls, Irene T1 - Mineral oil content in sediments and soils: comparability, traceability and a certified reference material for quality assurance N2 - The performance of twelve laboratories with previously established proficiency in the determination of the mineral oil content in a fresh water sediment is described. The summation parameter total petrol hydrocarbon (TPH) is defined according to ISO 16703:2004 with regard to the sample preparation to be applied, the flame ionisation detection (FID) and the boiling range of C10–C40 to be integrated. Comprehensive tests of homogeneity and stability have been carried out on the candidate material using appropriate models. The outcome of the study served as the basis for the certification of the candidate reference material as ERM-CC015a. The certified mass fraction is 1,820±130mgkg-1 and traceability was established by using an appropriate calibration standard certified for the mass fraction of C10–C40. The interlaboratory scatter of measurement results in this exercise can largely be explained by the variability of the individual calibrations based on this common calibration standard. KW - Total petroleum hydrocarbons KW - Extraction KW - Gas chromatography KW - Calibration KW - Interlaboratory study PY - 2006 DO - https://doi.org/10.1007/s00216-006-0423-4 SN - 1618-2642 SN - 1618-2650 VL - 385 IS - 3 SP - 645 EP - 651 PB - Springer CY - Berlin AN - OPUS4-12399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuhlich, Paul A1 - Emmerling, Franziska A1 - Piechotta, Christian A1 - Nehls, Irene T1 - Methyl 3,5,5,6,8,8-hexamethyl-5,6,7,8-tetrahydronaphthalene-2-carboxylate (AHTN-COOMe) N2 - Crystals of the title compound, C18H26O2, were grown from ethyl acetate. Due to the racemic precursor, the title compound is also obtained as a racemate. Disorder was observed during structure refinement, originating from two possible half-chair conformations of the non-aromatic ring. The disorder was refined by introducing split positions in the cyclo-hexane ring regarding the two possible R and S-enantiomers at the chiral CH group [ratio 0.744 (3):0.256 (3)]. The crystal structure features pairs of inversion-related molecules connected by pairs of non-classical C–H···O hydrogen bonds. KW - AHTN KW - Tonalide KW - Cyclic musk KW - AHTN-COOMe KW - Disinfection by-product KW - Esterification PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-232769 DO - https://doi.org/10.1107/S1600536811002601 SN - 1600-5368 VL - E67 IS - 2 SP - o485, sup-1 EP - sup-11 PB - Munksgaard CY - Copenhagen AN - OPUS4-23276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Schwarzer, Martin A1 - Becker, Roland A1 - Kuhnhardt, Claus A1 - Nehls, Irene T1 - Methodenvergleich zur Bestimmung von extrahierbaren organischem Halogen (EOX) in Bodenproben N2 - Ziel der vorliegenden Untersuchungen, die im Rahmen einer Diplomarbeit der Fachhochschule Lausitz/Senftenberg an der BAM durchgeführt wurden, war ein Vergleich unterschiedlicher Extraktionsverfahren für die Bestimmung von extrahierbarem organischem Halogen (EOX) in Bodenproben. EOX ist ein für die rasche Bewertung der Organochlor- Belastung kontaminationsverdächtiger Flächen wertvoller Summenparameter, der sämtliche mit organischen Lösungsmittel extrahierbare Organohalogenverbindungen erfasst. Gegenwärtig existiert jedoch kein für die Bodenanalytik genormtes Verfahren für die Durchführung von EOX-Bestimmungen. Daher wird in der Praxis auf das für Schlämme und Sedimente entwickelte Verfahren nach DIN 38414 S17 (1990) zurückgegriffen, so auch in der Bundesbodenschutz- und Altlasten-Verordung (BBodSchV). Literaturangaben und Erfahrungen mit der Wiederfindungsrate polarer Extraktionsmittel und moderner Extraktionsverfahren bei Organochlorpestiziden, die eine bedeutende Quelle für EOX in Schlämmen und Böden darstellen, lassen vermuten, dass das genannte Normverfahren systematisch zu Unterbefunden neigen könnte. Für die Untersuchungen wurden an der BAM entwickelte Boden-Referenzmaterialien mit "natürlicher", über jahrzehntelangen Eintrag entstandener DDT- und Lindan-Belastung verwendet. Neben den klassischen Extraktionsverfahren nach Soxhlet kamen die ultraschallunterstützte Extraktion, die Mikrowellen- und die beschleunigte Lösungsmittelextraktion (ASE) jeweils mit Lösungsmitteln unterschiedlicher Polarität zum Einsatz. Extraktionsausbeuten und Wiederholpräzision der einzelnen Varianten wurden verglichen und vor dem Hintergrund der Ergebnisse unabhängiger Verfahren wie der gaschromatographischen Bestimmung der einzelnen Organochlorverbindungen bewertet. Die Polarität des Extraktionsmittels weist auch bei trockenen Böden den größten Einfluss auf die Extraktionsausbeuten der in den untersuchten Proben enthaltenen Organochlorverbindungen auf. Die Mischung Hexan/Aceton (1:1), die sich für die Extraktion verschiedener organischer Parameter bewährt hat, ist hinsichtlich der EOX-Analytik der existierenden Norm überlegen. T3 - BAM Forschungsberichtreihe - 263 PY - 2003 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-1884 SN - 978-3-86509-083-4 SN - 0938-5533 VL - 263 SP - 1 EP - 64 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Jancke, Harald A1 - Nehls, Irene T1 - Messung und Quantifizierung von Mineralölkohlenwasserstoffen - Ein Vergleich von FT/IR, GC-FID und 1H-NMR KW - H-1-Kernresonanz-Spektroskopie KW - H-1-NMR KW - Fourier-Transform-Infrarot-Spektroskopie KW - FT/IR KW - GC-FID KW - Kapillargaschromatographie-Flammenionisationsdetektion KW - MKW KW - Mineralölkohlenwasserstoffe KW - Umweltanalytik PY - 1999 SN - 0934-3504 SN - 1865-5084 VL - 11 IS - 1 SP - 9 EP - 14 PB - Springer CY - Heidelberg AN - OPUS4-7041 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Merkel, Stefan A1 - Köppen, Robert A1 - Koch, Matthias A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - Lysergol monohydrate N2 - In the title compound [systematic name: (7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3,2-fg]quinoline-9-yl)methanol monohydrate], C16H18N2O·H2O, the non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar, with a maximum deviation of 0.659 (3) Å, and shows an envelope conformation. In the crystal, hydrogen bonds between the lysergol and water molecules contribute to the formation of layers parallel to (10-2). PY - 2012 DO - https://doi.org/10.1107/S1600536812002632 SN - 1600-5368 VL - 68 IS - 2 SP - o523, sup1 EP - sup8 PB - Munksgaard CY - Copenhagen AN - OPUS4-25401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Merkel, Stefan A1 - Köppen, Robert A1 - Koch, Matthias A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - Lumi-ergometrine - structural identification and occurrence in sclerotia N2 - The fungus Claviceps purpurea grows on grasses and cereal grains and produces six predominant ergot alkaloids. These toxic substances undergo different transformation reactions during storage and cereal processing. One of these reactions is the addition of water to a double bond in the ergoline skeleton. Since light is required for this process, the substances formed were named lumi-ergot alkaloids. From these, a new asymmetric carbon and consequently two epimers with different polarities are formed. For investigations of lumi-ergot alkaloids, ergometrine was used exemplarily as it represents one of the six ergot alkaloids predominantly formed by Claviceps purpurea. The main reaction product, the less polar compound of the two lumiergometrine epimers, was separated by HPLC and unambiguously identified as 10-(S)-lumi-ergometrine using X-ray structural analysis. A HPLC-MS/MS method was developed for the detection of this substance in sclerotia extracts. Using this method, the existence of both epimeric forms of lumiergometrine could be proved in the sclerotia. This is the first time that the existence of a lumi-transformation product of ergot alkaloids was proved in naturally grown samples. KW - Lumi-ergot alkaloids KW - Sclerotia KW - Claviceps purpurea KW - HPLC-MS/MS PY - 2012 DO - https://doi.org/10.1007/s12550-011-0116-5 SN - 0178-7888 VL - 28 IS - 1 SP - 59 EP - 66 PB - Springer CY - Berlin; Heidelberg AN - OPUS4-25442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neuhof, Torsten A1 - Köppen, Robert A1 - Koch, Matthias A1 - Nehls, Irene T1 - Letter: High-performance liquid chromatography/electrospray mass spectrometry analysis of the mycotoxin aurofusarin N2 - High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) can be used for simultaneous quantification of various mycotoxins in contaminated food samples. Therefore, multi-mycotoxin methods have been developed in the last couple of years. To enlarge these methods for further analytes, we have developed a LC-MS/MS method for the quantification of the mycotoxin aurofusarin. Additionally, further LC-MSn experiments were performed to demonstrate the fragmentation pattern of aurofusarin. Applicable multiple reaction monitoring (MRM) transitions of aurofusarin were found and optimized by parameter variation of the tandem mass spectrometer. The applicability of the developed method was tested by analysis of naturally contaminated wheat. KW - LC-MS/MS KW - Multi-mycotoxin method KW - Aurofusarin PY - 2008 DO - https://doi.org/10.1255/ejms.935 SN - 1469-0667 SN - 1356-1049 SN - 1365-0718 VL - 14 IS - 5 SP - 329 EP - 333 PB - IM Publications CY - Chichester AN - OPUS4-18199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Neuhof, Torsten A1 - Nehls, Irene ED - Jörg Peter Matthes, ED - Markus Frasch, ED - Marx, Wolfram ED - Johannes Oeler, T1 - Lebensmittelanalytik - Neue Referenzmaterialien KW - Referenzmaterialien KW - Acrylamid KW - Ochratoxin A KW - Methylquecksilber PY - 2007 VL - 3 IS - 5 SP - 16 EP - 17 PB - Succidia Verl. & Kommunikation CY - Darmstadt AN - OPUS4-16691 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nehls, Irene A1 - Koch, Matthias A1 - Köppen, Robert A1 - Siegel, David A1 - Merkel, Stefan A1 - Piechotta, Christian A1 - Becker, Roland A1 - Win, Tin T1 - Lebensmittelanalytik - eine neue Herausforderung für die BAM T2 - Lebensmittelchemisches Kolloquium der Universität Hohenheim CY - Stuttgart, Germany DA - 2009-11-19 PY - 2009 AN - OPUS4-20584 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nehls, Irene A1 - Koch, Matthias A1 - Köppen, Robert A1 - Siegel, David A1 - Merkel, Stefan A1 - Piechotta, Christian A1 - Becker, Roland A1 - Win, Tin T1 - Lebensmittelanalytik - eine neue Herausforderung an die BAM T2 - Einladung zum Institutskolloquium, Institut für Landschaftsdynamik, Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. CY - Müncheberg, Germany DA - 2010-02-16 PY - 2010 AN - OPUS4-21058 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Gebert, Antje A1 - Emmerling, Franziska A1 - Becker, Roland A1 - Nehls, Irene T1 - Koenigs-Knorr reaction of fusel alcohols with methyl (1-bromo-2,3,4-tri-O-acetyl-alpha-D-glucopyranosid)uronate leading to the protected alkyl glucuronides-crystal structures and high resolution 1H and 13C NMR data N2 - Crystal structures and high resolution 1H and 13C NMR spectral data for methyl (alkyl 2,3,4-tri-O-acetyl-β-D-glucopyranosid)uronates (alkyl = methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, n-pentyl, 2-methyl-1-butyl and 3-methyl-1-butyl) are presented. KW - D-Glucuronic acid derivates KW - X-ray analysis KW - High resolution NMR KW - Anomeric configuration KW - Synthesis PY - 2012 DO - https://doi.org/10.1016/j.carres.2012.01.002 SN - 0008-6215 SN - 1873-426X VL - 352 SP - 186 EP - 190 PB - Elsevier CY - Amsterdam AN - OPUS4-25759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Buge, Hans-Gerhard A1 - Becker, Roland A1 - Nehls, Irene T1 - Kalibrierstandard für die Mineralöl (MKW)-analytik mittels GC-FID KW - Kalibrierstand KW - Referenzmaterial KW - MKW KW - GC PY - 2005 SN - 0016-3538 VL - 49 IS - 11 SP - 207 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-11601 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Emmerling, Franziska A1 - Kraus, Werner A1 - Becker, Roland A1 - Nehls, Irene T1 - Isopropyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside N2 - The title compound, C17H26O10, was formed by a Koenigs-Knorr reaction of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide and propan-2-ol. The central ring adopts a chair conformation. The crystal does not contain any significant intermolecular interactions. PY - 2013 DO - https://doi.org/10.1107/S1600536812051483 SN - 1600-5368 VL - 69 IS - Part 2 SP - o157, sup-1 - sup-7 PB - Munksgaard CY - Copenhagen AN - OPUS4-27572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Retter, Utz A1 - Koch, Matthias A1 - Nehls, Irene T1 - Investigation of the optimization of the recovery of mineral oil from water N2 - A method has been derived to completely recover mineral oil dispersed in water. The method involves three steps: the emulsification of the mineral oil by adding amphiphiles, the breaking of the emulsion by adding salts and the extraction of the mineral oil by a non-polar aprotic solvent. Various amphiphiles and types and concentrations of salts were tested. By using amphiphiles with HLB numbers in the range 4.7 to 40 a complete recovery of the mineral oil could be obtained for a combination of salts Na2SO4 + NaH2PO4 with total ionic strength of 6 mol/L. PY - 1999 SN - 0937-0633 VL - 364 SP - 777 EP - 779 PB - Springer CY - Berlin AN - OPUS4-7524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Becker, Roland A1 - Jung, Christian A1 - Piechotta, Christian A1 - Nehls, Irene T1 - Investigation of extraction procedures and HPLC-DAD/MS for the determination of the brominated flame retardant tetrabromobisphenol A bis(2,3-dibromopropylether) in environmental samples N2 - A method for the determination of the novel brominated flame retardant tetrabromobisphenol A bis(2,3-dibromopropylether), 1,1'-(isopropylidene)bis[3,5-dibromo-4-(2,3-dibromo-propoxy)-benzene] (TBBPA-dbpe), was developed. Technical TBBPA-dbpe was purified and the results of a thorough physical characterisation are reported. The application of APCI-MS is discussed and the fragmentation patterns are described. Quantification of TBBPA-dbpe was done by HPLC-DAD using external calibration. The validation of the method was accomplished using sediment and sewage sludge samples spiked with defined amounts of authentic TBBPA-dbpe. The average recovery rates of TBBPA-dbpe from spiked samples ranged from 35 to 91% (sediment) and from 57 to 98% (sewage sludge) depending on the respective extraction method. Pressurised fluid extraction (PFE) and fluidised bed extraction were superior to classical Soxhlet and sonication procedures and yielded recovery rates between 90 and 98% with relative standard deviations of 2%. The limits of detection (DTC), identification (ID) and determination (DTM) using HPLC-DAD were 10, 21 and 30 ng g-1 in sediment and 22, 44 and 72 ng g-1 in sewage sludge, respectively. KW - Extraction KW - TBBPA-dbpe KW - Sewage sludge KW - Sediment KW - LC-MS KW - Mass spectrometry KW - APCI KW - HPLC-DAD PY - 2006 DO - https://doi.org/10.1007/s00216-006-0339-z SN - 1618-2642 SN - 1618-2650 VL - 384 IS - 7-8 SP - 1485 EP - 1492 PB - Springer CY - Berlin AN - OPUS4-12255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Nehls, Irene A1 - Dorgerloh, Ute T1 - Interlaboratory comparisons - demonstrating degree of equivalence N2 - The role of matrix reference materials in the process of demonstrating the degree of equivalence of measurement results obtained from intercomparisons is outlined, reviewing exemplary selected experience gained at BAM regarding the determination of organic contaminants in environmental matrices. The specific characteristics of reference materials employed in the process of demonstrating equivalence between laboratories in the course of proficiency testing as well as the development, comparison and validation of methods are elaborated. The demand is for series of appropriately characterised samples which are fit for the purpose and it is seen from representative examples that the utilisation of such tailor-made RM designed to tackle the specific need of an analytical problem dominates over certified matrix reference materials in this context. Concluding, the role of certified matrix reference materials in quality assurance is briefly looked at both from the user’s and providers’ points of view. KW - Certification KW - Equivalence KW - Method development KW - Proficiency testing KW - Reference materials PY - 2003 DO - https://doi.org/10.1007/s00769-003-0580-5 SN - 0949-1775 SN - 1432-0517 VL - 8 SP - 150 EP - 155 PB - Springer CY - Berlin AN - OPUS4-2848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schallschmidt, Kristin A1 - Becker, Roland A1 - Zwaka, H. A1 - Menzel, R. A1 - Johnen, D. A1 - Fischer-Tenhagen, C. A1 - Rolff, J. A1 - Nehls, Irene T1 - In vitro cultured lung cancer cells are not suitable for animal-based breath biomarker detection N2 - In vitro cultured lung cancer cell lines were investigated regarding the possible identification of volatile organic compounds as potential biomarkers. Gas samples from the headspace of pure culture medium and from the cultures of human lung adenocarcinoma cell lines A549 and Lu7466 were exposed to polypropylene fleece in order to absorb odour components. Sniffer dogs were trained with loaded fleeces of both cell lines, and honey bees were trained with fleeces exposed to A549. Afterwards, their ability to distinguish between cell-free culture medium odour and lung cancer cell odour was tested. Neither bees nor dogs were able to discriminate between odours from the cancer cell cultures and the pure culture medium. Solid phase micro extraction followed by gas chromatography with mass selective detection produced profiles of volatiles from the headspace offered to the animals. The profiles from the cell lines were largely similar; distinct differences were based on the decrease of volatile culture medium components due to the cells' metabolic activity. In summary, cultured lung cancer cell lines do not produce any biomarkers recognizable by animals or gas chromatographic analysis. KW - A549 KW - Honey bees KW - Odour discrimination task KW - Sniffer dogs KW - Solid phase microextraction KW - Volatile organic compounds KW - Volatilome PY - 2015 DO - https://doi.org/10.1088/1752-7155/9/2/027103 SN - 1752-7155 SN - 1752-7163 VL - 9 IS - 2 SP - 027103-1 EP - 027103-10 PB - IOP CY - Bristol AN - OPUS4-34161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Dorgerloh, Ute A1 - Helmis, M. A1 - Mumme, J. A1 - Diakité, M. A1 - Nehls, Irene T1 - Hydrothermally carbonized plant materials: Patterns of volatile organic compounds detected by gas chromatography N2 - The nature and concentrations of volatile organic compounds (VOCs) in chars generated by hydrothermal carbonization (HTC) is of concern considering their application as soil amendment. Therefore, the presence of VOCs in solid HTC products obtained from wheat straw, biogas digestate and four woody materials was investigated using headspace gas chromatography. A variety of potentially harmful benzenic, phenolic and furanic volatiles along with various aldehydes and ketones were identified in feedstock- and temperature-specific patterns. The total amount of VOCs observed after equilibration between headspace and char samples produced at 270 °C ranged between 2000 and 16,000 µg/g (0.2–1.6 wt.%). Depending on feedstock 50–9000 µg/g of benzenes and 300–1800 µg/g of phenols were observed. Substances potentially harmful to soil ecology such as benzofurans (200–800 µg/g) and p-cymene (up to 6000 µg/g in pine wood char) exhibited concentrations that suggest restrained application of fresh hydrochar as soil amendment or for water purification. KW - Hydrochar KW - Mass spectrometry KW - Flame ionization detection KW - Phenols KW - Benzenes PY - 2013 DO - https://doi.org/10.1016/j.biortech.2012.12.102 SN - 0960-8524 SN - 1873-2976 VL - 130 SP - 621 EP - 628 PB - Elsevier Applied Science CY - Barking, Essex AN - OPUS4-27616 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Dorgerloh, Ute A1 - Paulke, E. A1 - Mumme, J. A1 - Nehls, Irene T1 - Hydrothermal carbonization of biomass: Major organic components of the aqueous phase N2 - Process waters obtained from hydrothermal carbonization (HTC) of wheat straw, a biogas digestate derived thereof, and four woody biomass feedstocks were quantified regarding the total organic carbon (TOC) and selected organic compounds. HTC runs revealed that TOC loads were largely unaffected by process severity or type of feedstock whereas the C2–C6 fatty acids, determined by GC, displayed clear effects of temperature and feedstock. HPLC demonstrated simultaneously the initial increase and subsequent consumption of cellulose-derived furfural and 5-hydroxymethylfurfural as well as the increase of the lignin-derived 2-methoxyphenol. 2-Methylbenzofuran, an example for a substance potentially harmful to aquatic biota, was observed in high concentration in the HTC liquor from wheat straw-based feedstocks. KW - Furfurals KW - Gas chromatography KW - Liquid chromatography KW - Phenols KW - Process water KW - Total organic carbon PY - 2014 DO - https://doi.org/10.1002/ceat.201300401 SN - 0930-7516 SN - 1521-4125 VL - 37 IS - 3 SP - 511 EP - 518 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-30333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Lutz, A. A1 - Bremser, Wolfram A1 - Hilbert, S. A1 - Nehls, Irene T1 - How to improve reliability in groundwater analysis: over a decade of experience with external quality control in field campaigns on volatile halogenated compounds N2 - The reliability in measurement results obtained during environmental monitoring is crucial for the assessment and further planning of remediation efforts on the respective contaminated sites by the responsible authorities. A case study concerned with groundwater contaminated with perchloroethylene, trichloroethylene and 1,1,2-trichlorotrifluoroethane including their degradation products which involves private contract laboratories and an independent provider of quality assurance (QA) is presented. The experience gained with biannual monitoring campaigns over 14 years indicates that the selection of contractors on basis of accreditation status and successful performance in interlaboratory comparisons are not sufficient. Rather the auditing of the contractors by the QA provider prior to each campaign and the crosschecking of selected monitoring samples by the QA provider led to a lasting improvement of reliability in the contractors' measurement results. A mean deviation of 20% from the reference value determined by the QA provider for the crosschecked samples was reached. KW - Groundwater monitoring KW - External quality management KW - QM KW - VOC PY - 2012 DO - https://doi.org/10.1039/c1em10460h SN - 1464-0325 SN - 1464-0333 VL - 14 IS - 1 SP - 217 EP - 223 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-25288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -