An assessment of the current Chlamydia trachomatis laboratory practices in Germany.

BACKGROUND AND OBJECTIVES: Currently, no information is available about the number of Chlamydia trachomatis (CT) tests performed, testing facilities available or diagnostic methods used in Germany. This study aimed to map CT diagnostic facilities so that representative laboratories can be recruited for CT sentinel surveillance. METHODS: Using a questionnaire, we collected information about population coverage, the number of tests performed, accreditation and current testing methods and systems for German facilities that potentially offer CT diagnostics. RESULTS: Overall, 725/1,504 (48%) facilities responded; of the respondents, 143 reported that they perform CT diagnostics. Of the laboratories performing diagnostics, 45% were privately owned, and 42% were located in a hospital. Of the laboratories that provided information about their catchment area, 61% received samples from at least one federal state and therefore covered more than their surrounding area. The median length of time that CT diagnostics had been performed was 11.5 years. Over half (54%) of the laboratories that provided information on their accreditation status were accredited, for a median duration of 6 years. In accordance with national guidelines, 77% used nucleic acid amplification tests (NAAT) for acute CT infections. CONCLUSIONS: The long duration since Ct diagnostics have been performed and laboratories have been accredited can be seen as an indication of the high diagnostic quality of German laboratories. Additionally, laboratories mostly serviced doctors and patients from a large region and are not representative for people living in the area where the lab is located. This has to be considered when sampling representative labs for CT sentinel surveillance and further epidemiological studies.

Adaptation of a constructed wetland to simultaneous treatment of monochlorobenzene and perchloroethene.

Mixed groundwater contaminations by chlorinated volatile organic compounds (VOC) cause environmental hazards if contaminated groundwater discharges into surface waters and river floodplains. Constructed wetlands (CW) or engineered natural wetlands provide a promising technology for the protection of sensitive water bodies. We adapted a constructed wetland able to treat monochlorobenzene (MCB) contaminated groundwater to a mixture of MCB and tetrachloroethene (PCE), representing low and high chlorinated model VOC. Simultaneous treatment of both compounds was efficient after an adaptation time of 2 1/2 years. Removal of MCB was temporarily impaired by PCE addition, but after adaptation a MCB concentration decrease of up to 64% (55.3 micromol L(-1)) was observed. Oxygen availability in the rhizosphere was relatively low, leading to sub-optimal MCB elimination but providing also appropriate conditions for PCE dechlorination. PCE and metabolites concentration patterns indicated a very slow system adaptation. However, under steady state conditions complete removal of PCE inflow concentrations of 10-15 micromol L(-1) was achieved with negligible concentrations of chlorinated metabolites in the outflow. Recovery of total dechlorination metabolite loads corresponding to 100%, and ethene loads corresponding to 30% of the PCE inflow load provided evidence for complete reductive dechlorination, corroborated by the detection of Dehalococcoides sp.

Membrane-assisted liquid-liquid extraction coupled with gas chromatography-mass spectrometry for determination of selected polycyclic musk compounds and drugs in water samples.

Selected polycyclic musk compounds and drugs were extracted from water samples by membrane-assisted micro liquid-liquid extraction. The two-phase extraction system consisted of polyethylene membrane bags filled with an organic solvent. Chloroform proved to be most suited as acceptor phase to extract caffeine, Galaxolide, Tonalide, phenazone and carbamazepine from aqueous samples. The compounds were enriched from 50 mL sample into a volume of 500 microL of chloroform. Gas chromatography-mass spectrometry (GC-MS) was applied for analysis. The extraction procedure was optimised in regard to membrane material, extraction time and temperature. The evaluation of the entire analysis protocol found limits of detection that ranged from 20 to 200 ng/L. The linear range of calibration covered one magnitude with standard deviations between 4 and 12%. Method comparison with standard analysis techniques such as solid-phase extraction (SPE) combined with GC-MS as well as LC-MS-MS confirmed this method as an easy and reliable protocol, even for the monitoring of matrix-loaded wastewater. The analysis of real samples established the feasibility of the technique.

Solid-phase microextraction of phthalates from water.

Solid-phase microextraction (SPME) with six different non-polar and polar fibres was used to extract seven phthalate esters from water samples for analysis by gas chromatography-mass spectrometry. With regard to extraction efficiency and repeatability of the extractions, the 70-microm Carbowax-divinylbenzene fibre was especially suitable for the selected phthalates with water solubilities between 4200 mg l(-1) (dimethyl phthalate) and 0.0003 mg l(-1) (di-n-octyl phthalate). Linearity was controlled in the range between 0.02 and 10 microg l(-1). In analysed drinking water samples from Leipzig (Germany) and Katowice (Poland) four of the investigated phthalates [diethyl phthalate, di-n-butyl phthalate, butylbenzyl phthalate and di(2-ethylhexyl) phthalate] were found to be present in concentrations between 0.02 and 0.6 microg 1(-1).