Publications by authors named "Andreas T Roemmelt"

Sequential window acquisition of all theoretical fragment ion spectra (SWATH) is a data independent acquisition (DIA) method for very fast scanning quadrupole time-of-flight (QTOF) instruments. SWATH repeatedly cycles through 28 consecutive 20 Da precursor isolation windows detecting all precursor ions and fragments MS ALL like and yet fast enough to generate more than 10 data points over the chromatographic peak. It was already shown in previous publications that SWATH, despite its wide Q1 windows, allows the identification of different substances and that SWATH has a higher identification rate than data dependent acquisition approaches.

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Microflow liquid chromatography (MFLC) coupled to mass spectrometry (MS) is claimed to improve analysis throughput, reduce matrix effects and lower mobile phase consumption. This statement was checked within the framework of method validation of a multi-analyte procedure in clinical and forensic toxicology employing MFLC-MS/MS and conventional LC-MS/MS. 200 μL whole blood were spiked with 50 μL internal standard mixture and extracted by protein precipitation.

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Forensic and clinical toxicological screening procedures are employing liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques with information-dependent acquisition (IDA) approaches more and more often. It is known that the complexity of a sample and the IDA settings might prevent important compounds from being triggered. Therefore, data-independent acquisition (DIA) methods should be more suitable for systematic toxicological analysis (STA).

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Single hair analysis normally requires extensive sample preparation microscale protocols including time-consuming steps like segmentation and extraction. Matrix assisted laser desorption and ionization mass spectrometric imaging (MALDI-MSI) was shown to be an alternative tool in single hair analysis, but still, questions remain. Therefore, an investigation of MALDI-MSI in single hair analysis concerning the extraction process, usage of internal standard (IS), and influences on the ionization processes were systematically investigated to enable the reliable application to hair analysis.

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During autopsy of a 38-year-old man the forensic pathologist noted an atypical purple discoloration of the colon membrane. Hypothesis was that the discoloration could have been caused by ingestion of red beetroot. In order to exclude other toxicological causes for this finding and to analytically verify this hypothesis, colon membrane, blood and urine were screened not only for the typical forensically relevant substances but also for the main chromophoric beetroot compounds employing liquid chromatography-high-resolution mass spectrometry (LC-HRMS).

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