All
Determination of the Molar Mass Distribution of Phenol Formaldehyde Resins Using GPC
December 1st 2018Phenol formaldehyde resins (PFR) are used in various industrial products because of their versatile properties. Thermoplastic and thermo-reactive resin types differ in the degree of remaining reactive groups and their molar mass distribution (MMD). We compared the MMDs of two phenolic resins by gel permeation chromatography (GPC).
Determination of Pharmaceuticals from Serum
December 1st 2018This application note describes the determination of pharmaceuticals from serum using solid-phase extraction (SPE) with the hydrophilic-lipophilic balanced SPE phase CHROMABOND® HLB for analyte enrichment and for sample cleanup. The eluates from SPE are finally analyzed by HPLC–MS/MS on a NUCLEOSHELL® PFP core–shell phase.
Analysis of Phospholipid Classes by iHILIC®-Fusion
September 1st 2018Phospholipids (PLs) are the major components of cellular membranes. They are important for the functionality of membrane proteins or serve as precursors for second messengers. Several studies reveal the role of PL alterations in various diseases such as cancer (1). Therefore, it is crucial to identify and quantify PLs in complex biological samples for lipidomic studies and clinical research.
Analysis of 213 Pesticide Residues in Grapes by LC–MS/MS with Time-Managed MRM
September 1st 2018In this study, a fast, sensitive, and selective multiresidue method has been developed by coupling QuEChERS sample preparation with LC–MS/MS. Using time-managed-MRM™ in the QSight® triple quadrupole mass spectrometer, the optimum dwell time can be generated automatically for MRM transitions based on the number of coeluting transitions, expected cycle time, retention time, and tolerance time window of the targeted analytes. Such method automation results in improved data quality and better sensitivity, accuracy, and reproducibility, as demonstrated in this study by the results of 213 pesticide residues analyzed in grape samples.
Analysis of Fentanyl and Its Analogues in Human Urine by LC–MS/MS
September 1st 2018Abuse of synthetic opioid prescription painkillers such as fentanyl, along with a rapidly growing list of illicit analogues, is a significant public health problem. In this study, we developed a simple dilute-and-shoot method that provides a fast 3.5-min analysis of fentanyl and related compounds (norfentanyl, acetyl fentanyl, alfentanil, butyryl fentanyl, carfentanil, remifentanil, and sufentanil) in human urine by LC–MS/MS using a Raptor Biphenyl column.
UHP-SEC Analysis of Biosimilars
September 1st 2018The amounts of high- and low-molecular-weight impurities are critical quality attributes for a therapeutic protein. Size-exclusion chromatography (SEC), the standard technology for analyzing aggregation and fragmentation, was applied to elucidate the molecular similarity between an Adalimumab biosimilar antibody and the corresponding innovator product Humira.
Determination of Pharmaceuticals from Serum
September 1st 2018This application note describes the determination of pharmaceuticals from serum using solid-phase extraction (SPE) with the hydrophilic-lipophilic balanced SPE phase CHROMABOND® HLB for analyte enrichment and for sample cleanup. The eluates from SPE are finally analyzed by HPLC–MS/MS on a NUCLEOSHELL® PFP core–shell phase
Analysis of Polyethylene by Pyrolysis-GC×GC–MS
September 1st 2018This application note shows the pyrolysis-GC×GC–HRMS profiles of crude oils for more detailed separations and more complete characterization of complex matrices, especially on the speciation of heteroatoms such as sulphur-containing compounds.
Analysis of Cellulose Molecular Weight Distributions in DMAC
September 1st 2018SEC-MALS analysis of cellulose provides absolute molar mass distributions to understand the impact of different extraction processes. The biopolymer is solubilized in DMAC, enabling liquid chromatography without degradation.
Fast and Sensitive Analysis of Amino Acids Using Automated Pre-Column Derivatization
July 1st 2018The building blocks of peptides and proteins, amino acids, are present in animals, humans, and plants. The analysis of amino acids is of essential significance in several areas including food science, clinical diagnostics, and pharmaceutical products research. Classical liquid chromatography (LC) determination of amino acids is performed with sample pretreatment including pre-column as well as post-column derivatization to improve or enable spectroscopic detection.
In-Well Hydrolysis Using UCT’s Refine™ Ultra-Filtration Technology
July 1st 2018UCT’s Refine™ Ultra-Filtration Technology allows for sample precipitation and filtration to occur simultaneously in the individual column or well. A novel, hydrophobically treated, submicrometer frit combination facilitates the removal of sample proteins without a complicated extraction.
Analysis of Fentanyl and Its Analogues in Human Urine by LC–MS/MS
July 1st 2018Abuse of synthetic opioid prescription painkillers such as fentanyl, along with a rapidly growing list of illicit analogues, is a significant public health problem. In this study, we developed a simple dilute-and-shoot method that provides a fast 3.5-min analysis of fentanyl and related compounds (norfentanyl, acetyl fentanyl, alfentanil, butyryl fentanyl, carfentanil, remifentanil, and sufentanil) in human urine by LC–MS/MS using a Raptor Biphenyl column.
Analysis of Organophosphates in Lithium Ion Battery Electrolytes by HILIC–ESI-MS
December 1st 2017New separation techniques for the analysis of polar and ionic analytes have aroused great interest in the field of metabolomics and environmental investigation in the past two decades. Hydrophilic interaction liquid chromatography (HILIC) is a promising tool to address this challenge. HILIC separation is based on the polarity of analytes, which generally show stronger retention with increasing polarity according to the HILIC separation mechanism. Furthermore, the high content of organic solvent in the mobile phase leads to good ionization properties in the electrospray ionization (ESI), and consequently enhances the detection sensitivity by hyphenated mass spectrometry (MS) detector.