Agilent Manuals

This application note describes the use of mass spectrometry to identify metabolites in rice and related bacteria, and to investigate the relationship between metabolites and susceptibility or resistance of rice to bacterial blight

A fast, sensitive, and validated technique for confirming the presence of amphetamine drugs in whole blood using the Agilent G6410A Triple Quadrupole Mass Spec-trometer (QQQ) is presented. Excellent linearity is demon- strated over the range of approximately 15 to 1,000 ng/mL. The amphetamine drugs analyzed in this work include amphetamine, methamphetamine, methyl-enedioxyamphetamine (MDA), and methylenedioxymeth-amphetamine (MDMA) in blood. The drugs have been prepared using an extractive alkylation technique. The sample preparation is then followed by reverse-phase LC/MS/MS using a 1.8-µm particle size C18 column for high chromatographic resolution with a high-speed sepa-ration. As a result, elution times for both analytes and internal standards are all less than or equal to 3.6 min- utes.

Metabolomics is the comparative analysis of metabolites found in sets of similar biological samples. Since metabolites play vital roles in biological systems, metabolomics can be useful for finding and identifying biomarkers, or for obtaining a better understanding of the effects of drugs or diseases on both known and unexpected biological pathways. Successful metabolomic research requires effective metabolite extraction. For non-targeted metabolomics, extraction methods need to capture a broad range of cellular and biofluid metabolites, while excluding components such as proteins that are not intended for analysis. Extraction is made more challenging by the physico-chemical diversity of metabolites and by metabolite abundances that can vary by many orders of magnitude. Biphasic, liquid-liquid extraction is often used to extract metabolites. The nature of the organic and aqueous solvents, their volumes, solvent ratios, and aqueous solvent pH, however, must be considered carefully. They can significantly affect the total number of metabolites extracted and experimental reproducibility. This application note describes a method for liquid-liquid extraction of metabolites from erythrocytes. It demonstrates the importance of adjusting the aqueous/organic ratio to favor biphasic extraction.

This application note provides step-by-step procedures for creating and using a mass spectral library with NIST MS Search software.

This document describes the analysis challenges of D-penicillamine enkephalin (DPDPE) and the rapid sensitive analysis of DPDPE in cerebrospinal fluid using an Agilent 1100 Series LC/MSD mass spectrometer. DPDPE is a synthetic enkephalin used for pain control, which has proven difficult to analyze in the past. The document also provides detailed information on the experimental method and sample preparation process.

This application note describes a method for determining the metabolic stability profile of buspirone using an Agilent 1200 Series Rapid Resolution LC/TOF system on a short Rapid Resolution High Throughput (RRHT) column. Simultaneously, the main metabolites are identified in the same experiment by the automated use of a long RRHT column, which provides the necessary high resolution.

This application note describes the use of an Ion Trap LC/MS/MS intelligent database search to identify phosphorylation sites in peptides resulting from proteolytic digestion of a phosphorylated protein

This note describes the effect of coeluting internal standard concentration on the dynamic range of Ion Trap quantitative analyses and demonstrates the advantages of Ion Trap technology over triple-quadrupole instruments for quantitative applications in high-throughput environments.

This document describes the method of rapid protein characterization using microflow LC/MS/MS techniques. The method involves digestion of a protein followed by microflow LC separation of the peptide fragments. Each peptide fragment is automatically selected for collision induced dissociation (CID) using mass spectrometric techniques, including automated data-dependent scan functions. Protein identification is achieved by correlating uninterpreted protein and peptide tandem mass spectral data with sequences in protein or nucleotide databases using computer algorithms. This method offers the potential for automated high-throughput data analysis and provides a high degree of specificity to database searches due to the unique fingerprint-type pattern displayed by the tandem mass spectrum representing every amino acid sequence.

This application note describes a method for impurity profiling using capillary electrophoresis (CE) and ion trap mass spectrometry (IT).

This document discusses the importance of target analysis of pharmaceutical compounds in biological matrices, and demonstrates the use of an ion trap LC/MS/MS system for fast and sensitive quantitation of the benzodiazepine drug midazolam in human serum.

This document describes the polarity switching technology in mass spectrometric analysis and the ability of a mass spectrometer to switch polarities during a single chromatographic peak. This capability allows for the detection of various polarity molecules in unknown samples during a single run, saving time and improving data quality.

This technical note describes the new features of the Agilent 1100 Series LC/MSD Trap software Version 4.2, including the Dissect function, the MASCAT program, and the automatic gain calibration function.

Introduction to MALDI and its applications in protein and peptide analysis. Including the principle of MALDI, the analysis methods of MALDI, the advantages and disadvantages of MALDI