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Analytical Chemist (analytical + chemist)
Selected AbstractsP03 Type-I and -IV hypersensitivity to platinum saltsCONTACT DERMATITIS, Issue 3 2004Willeke Kamphof A 28-year-old female analytical chemist visited our patch test clinic with initially complaints of severe hand dermatitis. Later on she developed rhinitis, bronchial asthma and tightness of the chest. The complaints seemed work related: her condition improved during holidays and on sick leaves. She worked in a laboratory with several platinum salts and used different kinds of gloves (latex, nitril, etc.). Methods:, Patch tests were performed with the European Standard series and prick tests with common inhalant allergens. Patch-, prick- and open patch tests were carried out with various aqueous dilutions of platinum chloride (PtCl2). Results:, Patch tests with 0.01,2% PtCl2 were positive on day 2, 3 and 6, and at 0.001% a follicular reaction was found. The prick-test was already positive at the lowest concentration tested (0.001%). The open patch test, carried out retro-auricular, showed a positive reaction at 1 and 2% PtCl2 after 20 min. Controls in healthy volunteers (n = 5) were all negative. Discussion:, It is well known that platinum salts can cause type-I hypersensitivity reactions like allergic rhinitis, conjunctivitis, bronchial asthma and urticaria, also referred to as platinosis. Contact dermatitis to platinum salts, however, is very rare. In our patch test clinic, 78 patients were tested between 1987 and 2001 with PtCl2 2%. Only 2 women showed a positive patch test for PtCl2. The patient presented here, stopped working with platinum salts and recovered from all complaints. We interpret our case as occupational type-I and type-IV hypersensitivity to platinum salts with mucosal and dermal manifestations. [source] Comparative analysis of glycosylinositol phosphorylceramides from fungi by electrospray tandem mass spectrometry with low-energy collision-induced dissociation of Li+ adduct ionsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2001Steven B. Levery Glycosylinositol phosphorylceramides (GIPCs) are a class of acidic glycosphingolipids (GSLs) expressed by fungi, plants, and certain parasitic organisms, but not found in cells or tissues of mammals or other higher animals. Recent characterizations of fungal GIPCs point to an emerging diversity which could rival that already known for mammalian GSLs, and which can be expected to present a multitude of challenges for the analytical chemist. Previously, the use of Li+ cationization, in conjunction with electrospray ionization mass spectrometry (ESI-MS) and low-energy collision-induced dissociation tandem mass spectrometry (ESI-MS/CID-MS), was found to be particularly effective for detailed structural analysis of monohexosylceramides (cerebrosides) from a variety of sources, including fungi, especially minor components present in mixtures at extremely low abundance. In applying Li+ cationization to characterization of GIPCs, a substantial increase in both sensitivity and fragmentation was observed on collision-induced dissociation of [M,+,Li]+ versus [M,+,Na]+ for the same components analyzed under similar conditions, similar to results obtained previously with cerebrosides. Molecular adduct fragmentation patterns were found to be systematic and characteristic for both the glycosylinositol and ceramide moieties with or without phosphate. Interestingly, significant differences were observed in fragmentation patterns when comparing GIPCs having Man,1,,,2 versus Man,1,,,6Ins core linkages. In addition, it was useful to perform tandem product ion scans on primary fragments generated in the orifice region, equivalent to ESI-(CID-MS)2 mode. Finally, precursor ion scanning from appropriate glycosylinositol phosphate product ions yielded clean molecular ion profiles in the presence of obscuring impurity peaks. The methods were applied to detailed characterization of GIPC fractions of increasing structural complexity from a variety of fungi, including a non-pathogenic Basidiomycete (mushroom), Agaricus blazei, and pathogenic Euascomycete species such as Aspergillus fumigatus, Histoplasma capsulatum, and Sporothrix schenckii. The analysis confirmed a remarkable diversity of GIPC structures synthesized by the dimorphic S. schenckii, as well as differential expression of both glycosylinositol and ceramide structures in the mycelium and yeast forms of this mycopathogen. Mass spectrometry also established that the ceramides of some A. fumigatus GIPC fractions contain very little 2-hydroxylation of the long-chain fatty- N -acyl moiety, a feature that is not generally observed with fungal GIPCs. Copyright © 2001 John Wiley & Sons, Ltd. [source] Volatile compounds of original African black and white shea butter from Tchad and CameroonEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2006Sabine Krist Abstract Shea butter is used as an edible vegetable fat in many African countries. It can be utilized as a substitute or complete replacement for cocoa butter in various applications and plays an important role in traditional African medicinal practice. Although detection of volatile compounds by solid-phase micro-extraction gas-chromatography mass-spectroscopy (SPME-GC-MS) is a very reliable and reproducible technique, which can be used as an important part of authenticity checking, production monitoring and contamination detection, no published data about volatile compounds of shea butter are available so far. In this investigation, the characteristic volatiles in the headspace of original African shea butter samples were identified by using SPME-capillary-GC coupled to a mass selective detector. Almost 100,different volatile components were identified, e.g. fatty acids, saturated and unsaturated aldehydes and ketones, terpenes, and typical Maillard reaction products such as methylfuranes and pyrazines. Furthermore, the samples have been olfactorily evaluated by a panel of professional flavorists and trained analytical chemists. It can be stated that variations in processing conditions of shea butter result in considerable differences in the composition of headspace volatiles, detected by SPME-GC-MS and human olfaction. [source] Investigating the presence of pesticide transformation products in water by using liquid chromatography-mass spectrometry with different mass analyzers,JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2008Félix Hernández Abstract Many pesticide transformation products (TPs) can reach environmental waters as a consequence of their normally having a higher polarity than their parent pesticides. This makes the development of analytical methodology for reliable identification and subsequent quantification at the sub-microgram per liter levels necessary, as required under current legislation. In this paper we report the photodegradation of several pesticides frequently detected in environmental waters from the Spanish Mediterranean region using the high-resolution and exact-mass capabilities of hybrid quadrupole time-of-flight mass spectrometry (QTOF MS) hyphenated to liquid chromatography (LC). Once the main photodegradation/hydrolysis products formed in aqueous media were identified, analytical methodology for their simultaneous quantification and reliable identification in real water samples was developed using on-line solid-phase extraction (SPE)-LC-tandem MS with a triple-quadrupole (QqQ) analyzer. The methodology was validated in both ground and surface water samples spiked at the limit of quantification (LOQ) and 10 × LOQ levels, i.e. 50 and 500 ng/l, obtaining satisfactory recoveries and precision for all compounds. Subsequent analysis of ground and surface water samples resulted in the detection of a number of TPs higher than parent pesticides. Additionally, several soil-interstitial water samples collected from the unsaturated zone were analyzed to explore the degradation/transformation of some pesticides in the field using experimental plots equipped with lisimeters. Several TPs were found in these samples, with most of them having also been detected in ground and surface water from the same area. This paper illustrates the extraordinary potential of LC-MS(/MS) with QTOF and QqQ analyzers for qualitative/structural and quantitative analysis, respectively, offering analytical chemists one of the most powerful tools available at present to investigate the presence of pesticide TPs in water. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||