COSNET-a coherent optical subscriber network

A complete coherent multichannel system, designed for application in the local loop, is presented. The concept of a uni- and bidirectional system and its technical realization in a laboratory demonstrator are described. The network control, including frequency management of the bidirectional channels, and network security are discussed. Attention is paid to the scenario for evolution from a narrowband to a complete broadband system. All aspects are integrated in a demonstrator, which is capable of supporting a large number of narrowband and broadband distributive and communicative services. Novel technical solutions for frequency management, data induced polarization switching (DIPS), high-speed encryption, and network signaling are presented

Efficient approach for the comprehensive detection of unknown anabolic steroids and metabolites in human urine by liquid chromatography-electrospray-tandem mass spectrometry

The detection of new anabolic steroid metabolites and new designer steroids in urine is a challenge in doping analysis. An approach based on precursor ion scanning for the detection of unknown anabolic steroids and metabolites is proposed. The study of the MS/MS spectra of selected anabolic steroids revealed different fragmentation pathways at low and medium collision energy depending on the steroid structure. However, after analysis at high collision energy three common ions at m/z 105, m/z 91, and m/z 77 were found for all studied anabolic steroids. These ions can be explained by the fragmentation of the steroid structure and corresponded to the methyl tropylium, tropylium, and phenyl ions, respectively. Because of the theoretical low specificity of these ions, the simultaneous presence of all of them was used as a starting point to consider a substance as a possible anabolic steroid. Hence, the developed approach is based on the simultaneous acquisition of the precursor ion scan of m/z 105, 91, and 77. The specificity of this approach has been checked by the injection of several doping agents including beta-agonists, corticosteroids, beta-blockers, and diuretics. In general, only compounds with a steroidal structure showed a signal at all three selected m/z values although some exceptions have been found. The applicability of the method was tested for three different scenarios: the detection of steroid metabolites, the detection of unknown steroids, and the analysis of prohormones. In metabolic studies, several recently reported fluoxymesterone metabolites were also found using this method. For detection of unknown steroids, some negative urine samples were spiked with the designer steroid THG and 33 other anabolic steroids and treated as blind samples. Finally, the applicability of the developed approach for the analysis of dietary supplements was checked by the analysis of a prohormone where several impurities and/or degradation products were found

Development and validation of an LC-MS/MS method for the quantification of ephedrines in urine

The objective of this study was to develop a simple and robust LC-MS/MS method for the quantification of ephedrine type substances in urine. Sample preparation consisted of a 10-fold dilution step of the samples into the internal standard solution (ephedrine-d(3), 4 mu g/mL in water). Baseline separation of the diastereoisomers norpseudoephedrine-norephedrine and ephedrine-pseudoephedrine was performed On a C8-column using isocratic conditions followed by positive electrospray ionisation and tandem mass spectrometric detection. The mobile phase consisted of 98/2 (H2O/ACN) containing 0.1% HAc and 0.01% TFA. Calibration curves were constructed between 2.5 and 10 mu g/mL for norephedrine and norpseudoephedrine and 5 and 20 mu g/mL for ephedrine, pseudoephedrine and methylephedrine. The bias ranged from -5.5 to 12% for norephedrine, -4.1 to 8.0% for norpseudoephedrine, 0.3 to 2.1% for ephedrine,1.6 to 2.6% for pseudoephedrine and 2.9 to 5.0% for methylephedrine. Precision of the method varied between 2.8 and 10.4% for all compounds and the matrix effect was less than 15%. The applicability of the method has been checked by the analysis of 40 urine samples. The results were compared with those obtained with the common GC-NPD method. Results show a good correlation between both methods with correlation coefficients higher than 0.95 for all analytes. (C) 2009 Elsevier B.V. All rights reserved

Detection of urinary markers for thiazide diuretics after oral administration of hydrochlorothiazide and altizide-relevance to doping control analysis

In sports. thiazide diuretics are used to flush out previously taken prohibited substances with forced diuresis and in sports where weight classes are involved to achieve acute weight loss. Thiazide diuretics include compounds which are very unstable and hydrolyse in aqueous media. Because information regarding the urinary detection of the hydrolysis products is limited, urinary excretion profiles for the hydrolysis product 4-aniino-6-chloro-1,3-benzenedisulphonamide were established in 6 healthy volunteers after oral administration of altizide (15 mg per tablet) and hydrochlorothiazide (25 mg per tablet). Additionally, the excretion profile of chlorothiazide, a metabolite of altizide and hydrochlorothiazide, was also determined. A quantitative liquid-chromatographic tandem mass spectrometric method to detect the 4 substances was developed and validated. The result of this work shows that altizide is eliminated within 48 h in urine whereas hydrochlorothiazide was detectable after 120 h. Chlorothiazide was determined to be a minor metabolite of altizide and hydrochlorothiazide and could be detected up to 120 h. The hydrolysis product, 4-amino-6-chloro-1.3-benzenedisulphonamide, was detectable 120 h after administration, with concentrations at least 10 times higher than the parent drug. Concentrations ranged between 41-239 and 60-287 ng/mL after altizide and hydrochlorothiazide administration, respectively. The study shows that 4-amino-6-chloro-1,3-benzenedisulphonamide is an important target compound for the long time detection of thiazide diuretics in urine. (c) 2009 Elsevier B.V. All rights reserved

Quantitative detection of inhaled salmeterol in human urine and relevance to doping control analysis

Salmeterol is a frequently prescribed beta(2)-agonist used for the treatment of asthma. Due to performance-enhancing effects of some beta(2)-agonists, salmeterol appears on the prohibited list published by the World Anti-Doping Agency and its therapeutic use is allowed but restricted to inhalation. Because the data on urinary concentrations originating from therapeutic use are limited, no discrimination can be made between use and abuse when a routine sample is found to contain salmeterol. Therefore, the urinary excretion of 100 mu g of inhaled salmeterol was investigated. A liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of urine samples. Sample preparation consists of an enzymatic hydrolysis of the urine samples followed by a liquid-liquid extraction at pH 9.5 with diethyl ether/isopropanol (5/1). Analysis was performed using selected reaction monitoring after electrospray ionization. The method was linear in the range of 0.5-50 ng/mL. The limits of quantification were 500 pg/mL. The inaccuracy ranged between 10.4% and -3.7%. Results show that salmeterol could be detected for 48 hours. The maximum urinary concentration detected was 1.27 ng/mL. Cumulative data showed that only 0.27% of the administered dose is excreted as parent drug within the first 12 hours. Analysis of 47 routine doping samples, declared to contain salmeterol during routine analysis, did not exhibit concentrations that could be considered originating from supratherapeutic doses