TY - CONF A1 - Malz, Frank A1 - Jancke, Harald A1 - Radeglia, Reiner T1 - Gehaltsbestimmung von Ethanol in wässriger Matrix (forensische Chemie) mittels quantitativer 1H-Wasserunterdrückungs-NMR T2 - GDCh-NMR-Diskussionstagung "Praktische Probleme der Kernresonanzspektroskopie" CY - Erlangen, Deutschland DA - 2004-01-12 KW - Quantitative NMR KW - Wasserunterdrückung KW - Gehaltsbestimmung KW - Ethanol PY - 2004 SP - 10 PB - GDCh CY - Erlangen AN - OPUS4-3061 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schubert, G. A1 - Reck, Günter A1 - Jancke, Harald A1 - Kraus, Werner A1 - Patzelt, C. T1 - Uric acid monohydrate - a new urinary calculus phase N2 - In our laboratory more than 100,000 urinary calculi have been analysed since 1972. Amongst this huge sample, 15 specimens originating from a total of eight patients were observed showing similar characteristics but escaping unambiguous identification with any of the substances that have been described so far in urinary concrements. Therefore, the unknown substance was submitted to a more extended analytical regimen. Structural analysis by x-ray crystallography turned out to be most successful, identifying the unknown material as uric acid monohydrate. Uric acid monohydrate crystallizes in the monocline space group P21/c. Within the crystal, uric acid and water molecules form continuous layers by hydrogen bonds. This is in contrast to uric acid in its water free and its dihydrate forms, which both crystallize by forming 3-dimensional networks To the best of our knowledge , the existence of a monohydrate form of uric acid has not been reported so far. Accordingly, this is the first report on uric acid monohydrate as a urinary stone component. The frequency of only 0.015% in our survey indicates that uric acid monohydrate is rarely the main component in concrements, in contrast to uric acid and uric acid dihydrate with frequencies of 10% and 6%, respectively. The infrared spectrum of uric acid monohydrate is very similar to that of the other crystal forms of uric acid. Because of this similarity and its low frequency, uric acid monohydrate may have been overlooked as a component of urinary concrements. X-ray diffraction allows for better differentiation in routine stone analysis. All samples of uric acid monohydrate were found by solid state NMR spectroscopy to be highly contaminated by amorphous material. This material consisted of long aliphatic chains reminiscent of lipids and fatty acids, respectively. Concrements consisting of other forms of uric acid or urate lacked this amorphous component. Therefore, a role of this aliphatic material has to be taken into consideration when discussing the conditions that may favour the rare formation of concrements from uric acid monohydrate. As for as the metabolic situation of the affected patients is concerned, no common peculiarities became evident by a retrospective survey. KW - Uric acid monohydrate KW - Urinary calculus KW - Crystal structure KW - Solid state NMR KW - X-ray diffraction KW - Infrared spectroscopy PY - 2005 DO - https://doi.org/10.1007/s00240-005-0467-5 SN - 0300-5623 SN - 1434-0879 VL - 33 IS - 3 SP - 231 EP - 238 PB - Springer CY - Berlin AN - OPUS4-7676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jancke, Harald T1 - Quantitative Analysen mittels strukturanalytischer Verfahren T2 - GDCh Seminar "Qualitätssicherung im chemischen Labor, Teil II" CY - Leipzig, Germany DA - 2003-10-28 PY - 2003 AN - OPUS4-3745 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Malz, Frank A1 - Jancke, Harald A1 - Radeglia, Reiner A1 - Hässelbarth, Werner T1 - Messunsicherheit der quantitativen hochauflösenden NMR-Spektroskopie T2 - GDCh-NMR-Diskussionstagung "Praktische Probleme der Kernresonanzspektroskopie" CY - Bochum, Deutschland DA - 2003-01-13 PY - 2003 SP - 1(?) PB - GDCh CY - Erlangen AN - OPUS4-2226 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jancke, Harald T1 - Die NMR-Ringversuche der BAM (bis Juni 2002) Anliegen - Stand - Ergebnisse T2 - Workshop zum Ringversuch BAM-NMR-3 CY - Berlin, Germany DA - 2002-06-18 PY - 2002 AN - OPUS4-2952 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jancke, Harald T1 - NMR-Spektroskopie aus metrologischer Sicht T2 - BAM-Kolloquium CY - Berlin, Germany DA - 2004-03-24 PY - 2004 AN - OPUS4-4014 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jancke, Harald A1 - Malz, Frank T1 - Qualitätsanforderung an die quantitative NMR-Spektroskopie PY - 2004 SN - 0016-3538 SP - 492 EP - 493 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-5340 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Malz, Frank A1 - Jancke, Harald T1 - Validation of quantitative NMR N2 - NMR is by definition a quantitative spectroscopic tool because the intensity of a resonance line is directly proportional to the number of resonant nuclei (spins). This fact enables, in principle, a precise determination of the amount of molecular structures and, hence, of substances in solids as well as liquids. With the increase of sensitivity due to stronger and stronger static magnetic fields including improved electronics the detection limits have been pushed down significantly. However, the lack of a precise protocol that considers and controls the aspects of both the measurement procedure as well as the spectra processing and evaluation is responsible for the fact that quantitative investigations of identical samples in various laboratories may differ severely (deviations up to 90% relative to gravimetric reference values). Here, a validated protocol for quantitative high resolution 1H-NMR using single pulse excitation is described that has been confirmed by national and international round robin tests. It considers all issues regarding linearity, robustness, specificity, selectivity and accuracy as well as influences of instrument specific parameters and the data processing and evaluation routines. This procedure was tested by the investigation of three different 5-model-compound mixtures. As a result of the round robin tests using the proposed protocol it was found that the maximum combined measurement uncertainty is 1.5% for a confidence interval of 95%. This applies both for the determination of molar ratios and of the amount fractions of the various components. Further, the validation was extended to purity determinations of substances as shown for 1,8-epoxy-p-menthane (cineole). KW - Validation KW - Quantitative NMR KW - Cineole KW - Purity KW - Round robin test PY - 2005 DO - https://doi.org/10.1016/j.jpba.2005.01.043 SN - 0731-7085 SN - 1873-264X VL - 38 IS - 5 SP - 813 EP - 823 PB - Pergamon Press CY - Oxford AN - OPUS4-11813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jancke, Harald A1 - Malz, Frank A1 - Hässelbarth, Werner T1 - Structure analytical methods for quantitative reference applications N2 - The analytical methods mass spectrometry, UV/Vis, IR, Raman, Fluorometry, XRD, Mössbauer, and NMR used to elucidate chemical structure are evaluated regarding their capabilities to be used as primary analytical techniques in quantitative measurements, considering the criteria in the CCQM definition of primary methods. This includes a review of the respective measurement equations, the evaluation of the measurement uncertainty, and a discussion of evidence for the “highest metrological level”, as obtained from intercomparisons in contest with other methods. It is shown that only few methods fulfill the CCQM criteria. Quantitative NMR spectroscopy is one of them and may be considered as a potential primary method as recommended by CCQM because of being free of empirical factors in the uncertainty budget. KW - Metrology KW - Structure analysis KW - Quantitative analysis KW - Primary methods KW - Reference methods PY - 2005 DO - https://doi.org/10.1007/s00769-005-0004-9 SN - 0949-1775 SN - 1432-0517 VL - 10 IS - 8 SP - 421 EP - 429 PB - Springer CY - Berlin AN - OPUS4-11814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Brita A1 - Jancke, Harald A1 - Müller, Renate A1 - Peplinski, Burkhard A1 - Hähnert, Manfred ED - Rüssel, C. T1 - Sol-gel derived precursors for cordierite glass-ceramics T2 - 5th International Otto Schott Colloquium ; 5. Internationales Otto-Schott-Kolloquium CY - Jena, Germany DA - 1994-07-10 PY - 1994 SN - 0946-7475 N1 - Serientitel: Glass science and technology – Series title: Glass science and technology IS - 67 SP - 448 EP - 451 PB - Verl. Dt. Glastechn. Ges. CY - Frankfurt/Main AN - OPUS4-12598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Malz, Frank A1 - Jancke, Harald T1 - Purity assessment problem in quantitative NMR - impurity resonance overlaps with monitor signal multiplets from stereoisomers N2 - This paper describes the situation that can emerge when the signals to be evaluated in quantitative NMR measurements—so-called “monitor signals”—consist of several resonance lines from the stereoisomers of the analyte in addition to an impurity signal underneath. The monitor signal problem is demonstrated in the purity assessment of two samples of 2-(isopropylamino)-4-(ethylamino)-6-chloro-1,3,5-triazine (atrazine), a common herbizide which served as analyte in a CCQM intercomparison. It is shown that, in DMSO-d6 solution, a mixture of stereoisomers leads to several individual overlapping singlets, which are further split by spin–spin coupling. A measurement protocol was developed for finding and identifying an impurity that has a signal that is positioned precisely beneath the methyl signal chosen as the monitor signal in one of the samples. Quantitative NMR purity assessment is still possible in this special case, but with higher uncertainty. KW - Quantitative NMR KW - Monitor signal KW - Impurities KW - Atrazine KW - Purity assessment PY - 2006 DO - https://doi.org/10.1007/s00216-006-0415-4 SN - 1618-2642 SN - 1618-2650 VL - 385 IS - 4 SP - 760 EP - 765 PB - Springer CY - Berlin AN - OPUS4-13713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -