The combination of automated solid-phase extraction (SPE) and large-volume introduction gas chromatography electron-capture detection (GC-ECD) is used for the determination of synthetic pyrethroids in surface and drinking water. The selectivity that is needed for the use of GC-ECD of environmental samples is achieved by addition of a polarity modifier to the sample. In this study, sufficient methanol was added to 19 ml of sample to obtain a level of 30% of modifier prior to SPE. The cartridge is washed with one additional ml of 30% methanol in water. After drying, the cartridge is eluted with toluene. GC-ECD analysis is performed by on-column introduction of 100 microliters of the toluene extract. The whole procedure was automated by using an automated solid-phase extraction apparatus. Limits of detection (LODs) for the pyrethroids in surface water are in the range of 1 to 8 ng/1 (signal-to-noise ratio = 3); even lower limits of detection are possible for drinking water.
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http://dx.doi.org/10.1016/0021-9673(95)00142-5 | DOI Listing |
J Proteome Res
January 2025
Discovery Research, AbbVie, Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States.
Affinity capture (AC) combined with mass spectrometry (MS)-based proteomics is highly utilized throughout the drug discovery pipeline to determine small-molecule target selectivity and engagement. However, the tedious sample preparation steps and time-consuming MS acquisition process have limited its use in a high-throughput format. Here, we report an automated workflow employing biotinylated probes and streptavidin magnetic beads for small-molecule target enrichment in the 96-well plate format, ending with direct sampling from EvoSep Solid Phase Extraction tips for liquid chromatography (LC)-tandem mass spectrometry (MS/MS) analysis.
View Article and Find Full Text PDFFood Res Int
February 2025
Hematology Laboratory, Shengjing Hospital of China Medical University, Shenyang 110004, China. Electronic address:
Background: Furfurals, key derivatives of Maillard reactions commonly found in everyday foods, have been identified as having significant toxic effects on human health. Excessive intake of furfurals can lead symptoms such as weight loss, poor nutrient metabolism which followed by disease occurrence. The severe carcinogenicity, mutagenicity and genotoxicity of furfurals were well recognized recently.
View Article and Find Full Text PDFSe Pu
February 2025
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
To evade legal controls, new psychoactive substances (NPS), which have been designed as substitutes for traditional and synthetic drugs, are gradually dominating the drug market. Synthetic cannabinoids (SCs), which account for the majority of NPS, are rapidly being derivatized; consequently, controlling increasing abuse by merely listing individual compounds is difficult. Therefore, China has included the entire SC category of SCs listed as legal controlled substances since July 1, 2021.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
The remarkable efficiency with which enzymes catalyze small-molecule reactions has driven their widespread application in organic chemistry. Here, we employ automated fast-flow solid-phase synthesis to access catalytically active full-length enzymes without restrictions on the number and structure of noncanonical amino acids incorporated. We demonstrate the total syntheses of iron-dependent myoglobin (BsMb) and sperm whale myoglobin (SwMb).
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, F-35000, Rennes, France.
Background: Considering the large diversity of chemicals present in the environment and the need to study their effects (alone or as mixtures), the development of high-throughput in vitro assays in line with the Replacement, Reduction, Refinement (3R) strategy is essential for chemical risk assessments.
Results: We developed a robust analytical workflow based on both low resolution tandem mass spectrometry (MS/MS) and high-resolution mass spectrometry (HRMS) to quantify 13 steroids in NCI-H295R cell culture medium, human plasma and serum. The workflow was validated by screening media from the NCI-H295R cell line exposed in dose-response experiments to 5 endocrine disruptors (EDs) such as bisphenol A, prochloraz, ketoconazole, atrazine and forskolin.
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