Thermo Fisher Scientific

Articles by Thermo Fisher Scientific

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Biotherapeutic peptides and proteins are often PEGylated (covalently bonded to polyethylene glycol polymers) to improve bioavailability, reduce immunogenicity, and extend circulating half-life (1). Achieving the desired properties for each application depends on optimizing the number and site of polymers attached, chain length, and the degree of chain branching.

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Tetracycline (TC), a common antibiotic used to treat urinary tract infections, acne, gonorrhea, and other conditions, yields a toxic degradation product, 4-epianhydrotetracycline (EATC). General Chapter 226 of the U.S. Pharmacopeia and National Formulary (USP-NF), referred to by monographs for epitetracycline and drug products containing tetracycline hydrochloride (TC-HCl), prescribes an antiquated assay for EATC impurity in TC.

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The screening of pesticides, mycotoxins, and veterinary drugs is of great importance in regulated environments such as food or feed analysis. Due to some of the limitations of traditional triple quadrupole approaches (for example, targeted analyte detection, limited number of compounds, and unidentified unknown compounds), there is currently a trend towards use of full-scan MS data for the analysis of residue samples. Current screening approaches mainly rely on the use of ToF instruments coupled to U-HPLC delivering mass accuracy (~5 ppm) at a maximum resolution of <15,000. This can produce inaccurate mass measurements due the presence of unresolved background matrix interferences. In this work we show a full-scan MS screening approach with the Thermo Scientific Exactive mass spectrometer, a novel single-stage Orbitrapâ„¢ MS capable of providing precise mass accuracies at resolutions of up to 100,000 without the need for internal mass calibration.

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Polybrominated diphenyl ethers (PBDEs) are bioaccumulativetoxic compounds that are used as flame retardants. They have high boiling points and low thermal stability which makes analysis by GC–MS challenging. Additional bromines increase the thermal instability. A method was developed to analyze for polybrominated biphenyls using a large volume injection, short analytical column, and high mass tuning algorithm on the Thermo Scientific DSQ II with detection by EI Single Ion Monitoring (SIM).