J Chromatogr B Analyt Technol Biomed Life Sci
June 2021
To date, few tools are available for the analysis of the glycome without derivatization, a process which is known to introduce issues such as differential loss of sialic acid and incomplete labeling. We have previously reported the use of ion chromatography-mass spectrometry (IC-MS) to analyze native sialylated and sulfated glycans. Here, we introduce improvements to IC column technology, enabling the separation of neutral glycans while maintaining charge separation capabilities.
View Article and Find Full Text PDFIon chromatography-electrospray tandem mass spectrometry (IC-ESI-MS/MS) is used to determine nine haloacetic acids (HAAs), bromate, and dalapon in drinking water samples in U.S. EPA Method 557.
View Article and Find Full Text PDFA design-of-experiment (DoE) model was developed, able to describe the retention times of a mixture of pharmaceutical compounds in hydrophilic interaction liquid chromatography (HILIC) under all possible combinations of acetonitrile content, salt concentration, and mobile-phase pH with R > 0.95. Further, a quantitative structure-retention relationship (QSRR) model was developed to predict retention times for new analytes, based only on their chemical structures, with a root-mean-square error of prediction (RMSEP) as low as 0.
View Article and Find Full Text PDFLabeling of released asparagine-linked (N-linked) oligosaccharides from glycoproteins is commonly performed to aid in the separation and detection of the oligosaccharide. Of the many available oligosaccharide labels, 2-amino benzamide (2-AB) is a popular choice for providing a fluorescent product. The derivatization conditions can potentially lead to oligosaccharide desialylation.
View Article and Find Full Text PDFHeparan sulfate (HS) and chondroitin sulfate/dermatan sulfate (CS/DS) glycosaminoglycans (GAGs) participate in many important biological processes. Quantitative disaccharide analysis of HS and CS/DS is essential for the characterization of GAGs and enables modeling of the GAG domain structure. Methods involving enzymatic digestion and chemical depolymerization have been developed to determine the type and location of sulfation/acetylation modifications as well as uronic acid epimerization.
View Article and Find Full Text PDFMany different techniques have been developed to prepare monolithic materials specifically for chromatographic techniques. The two most popular polymerization techniques being thermal or via ultra violet (UV) light. Whereas thermal polymerization is easily employed for a whole variety of monomer and porogen systems, UV polymerization has been limited to methacrylate-based systems, and styrenic systems have been avoided due to their strong absorbance at low wavelengths.
View Article and Find Full Text PDFThe effect of Fe³(+) treatment on weak cation exchange column chromatography was demonstrated for monoclonal antibody (MAb) analysis. Fe³(+)-exposed columns showed lowered relative peak areas of the parent MAb peak as well as both acidic and basic variant peaks that could lead to erroneous conclusions. Accurate measurement of relative amounts of variants to the parent MAb is essential for demonstrating the safety and efficacy of therapeutic molecules such as MAbs.
View Article and Find Full Text PDFPerformance of procedures upon the obese critically ill patient in the ICU or in the radiology suite, require certain considerations. Additional staff, equipment and proper ergonomics are often necessary to perform these procedures safely for both patient and staff.
View Article and Find Full Text PDFTwo inline matrix diversion methods were developed for the sensitive analysis of perchlorate in a matrix comprising up to 1000 mg l(-1) of chloride, sulfate and bicarbonate ions using suppressed ion chromatography and conductivity detection. The first method used a cryptand C1 concentrator column, which exhibited a high selectivity for perchlorate ion over the other matrix anions. After retaining the sample anions in a concentrator column derivatized with a crytpand phase, a rinse step was implemented with a weak base to divert the matrix ions to waste while selectively retaining perchlorate in the concentrator column for subsequent analysis.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
December 2005
A capillary-scale high-pH anion-exchange chromatography (HPAEC) system for the analysis of carbohydrates was developed, in combination with two parallel on-line detection methods of sub-picomolar sensitivity: (1) pulsed amperometric detection (PAD); (2) capillary-scale desalting followed by electrospray ion-trap (IT) mass spectrometry (MS). The capillary chromatographic system combined the superb selectivity of HPAEC that allows routine separation of isomeric oligosaccharides with the information on monosaccharide sequence and linkage positions obtained by MS/MS fragmentation using the IT-MS. The applicability of the system in biomedical research was demonstrated by its use for the analysis of a urine sample of a GM1-gangliosidosis patient.
View Article and Find Full Text PDFThe International Agency for Research on Cancer determined that bromate is a potential human carcinogen, even at low micro/l levels in drinking water. Bromate is commonly produced from the ozonation of source water containing naturally occurring bromide. Traditionally, trace concentrations of bromate and other oxyhalides in environmental waters have been determined by anion exchange chromatography with an IonPac AS9-HC column using a carbonate eluent and suppressed conductivity detection, as described in EPA Method 300.
View Article and Find Full Text PDFJ Biochem Biophys Methods
September 2004
Recent developments in new electrolytic devices that utilize the electrolysis of water and charge-selective electromigration of ions through ion-exchange media have significantly changed the routine operation of ion chromatographic methods. Examples of these new electrolytic devices include on-line eluent generators that produce high-purity electrolyte eluents using deionized water as the carrier stream, continuously regenerated trap columns that remove ionic contaminants in the eluents, and continuously regenerated suppressors that reduce eluent background conductance prior to conductivity detection. The combined use of these electrolytic devices has made it possible to perform various ion chromatographic separations using only deionized water as the mobile phase.
View Article and Find Full Text PDFAn ion chromatographic method was developed for the determination of nine inorganic and organic acid anions at sub- to low-microg/l levels in power plant water samples. In this method, samples were injected using a large-volume direct injection technique, the analyte anions were separated on a hydroxide-selective anion-exchange column using high-purity hydroxide eluents generated by an on-line electrolytic eluent generator and detected using the suppressed conductivity detection method. The method performance was evaluated by analyzing synthetic water samples containing additives encountered in the power plant water samples and four water samples from a fossil fuel power plant.
View Article and Find Full Text PDF