Agilent Manuals

This Application Note describes the configuration and set up of a purification system for the isolation of radiolabeled drug metabolites from biological samples applied by an injection pump system. Various fraction collection options, for example, time-based fraction collection monitored by a radiochemical detector or peak-based fraction collection on the radiochemical detector signal are described.

The present invention discloses a new type of liquid chromatography column, which has a short column length and small particle size, and can achieve efficient high-throughput analysis.

This method uses the Agilent Total RNA Isolation Mini Kit to isolate high-purity RNA from yeast cells. The method has the advantage of removing cellular contaminants such as proteins, carbohydrates, and genomic DNA, resulting in a purer RNA product. The method uses a carefully prepared yeast spheroplast followed by complete homogenization of the sample to remove high levels of cell wall components and other proteins, thus achieving high efficiency in the separation of yeast RNA. Compared with other commercial methods, the Agilent method yields comparable yeast total RNA yield and contains significantly less genomic DNA than RNA isolated with a competitor's silica-based kit. Agilent 2100 Bioanalyzer analysis showed that the isolated RNA had high quality and integrity.

This Application Note demonstrates the mass-based purification of low gram amounts of compounds using the Agilent 1100 Series purification platform. Starting the experiments on 21.2-m i.d. columns two application examples were scaled up to a 50-mm i.d. column operated at 100 mL/min. Fractions with purities of 85 and 95 % were obtained by mass-based fraction collection even though the column overload did not allow the UV-trace to show separated peaks.

Accurate mass measurements can be used to both confirm the presence of a compound and help identify unknowns. Obtaining accurate mea- surements using mass spectrometry has typically required highly skilled operators doing interactive instrument operation and data manipula- tion. This Application Note describes how using the Agilent LC/MSD TOF and new software for walk-up operation, chemists can get the accurate mass information they need easily and without much training.

This application note describes the preparative isolation of corticosteroid degradation products using mass-based fraction collection.

This application note describes the use of the Agilent 2100 bioanalyzer for stringent RNA quality control and the advantages of this method for high-resolution analysis of small and very small RNA samples.

This application note describes how the attributes of Time of Flight and Trap mass spectrometry can be combined to provide a highly reliable identification for an unknown compound. Time of Flight mass spectrometry provides a very accurate mass for the parent compound, and Trap mass spectrometry provides fragmentation data; together they greatly diminish the number of candidate compounds, and increase the confidence in a confirmation.

This article investigates the structure identification and confirmation of degradation products of the antibiotic drug amoxicillin. Accurate mass measurement and empirical formula confirmation for the compound ions and CID fragments were performed using ESI TOF.

This document describes experimental modifications to inhibit ionization suppression when using LC-ESI-MS in negative ion mode for steroid estrogens and acidic herbicides. It introduces the problem of ionization suppression and methods to reduce its effects. The application of matrix clean-up in water samples to improve the apparent extraction efficiency of the analyte of interest when using LC-ESI-MS in negative ion mode is also discussed.

The document describes the metabolism of drugs in the body and the impact of enzyme activity on the formation and excretion rate of metabolites. The CYP3A4 and CYP2D6 enzyme families are considered the most important in this activity. The document uses dextromethorphan as a probe for the activity of the CYP2D6 metabolic phenotype and describes the metabolism and excretion of the drug in different metabolic types of patients. Additionally, the document mentions that some individuals have multiple copies of the gene that produces the CYP2D6 enzymes, leading to high metabolic rates of many drugs in these individuals and rendering the drugs therapeutically ineffective.

DuraGuard Columns: GC Columns with Built-In Protection

This application note demonstrates the identification and confirmation of degradation products, which have emerged in a formulation trial of the antibiotic drug amoxicillin under non-optimal conditions.

Agilent Reversed Phase Prep columns demonstrated both good loadability and good scalability for calcium channel blockers using gradient conditions. The columns also dis- played good resolution at all dimensions and allowed a linear scaleup from analytical to preparative dimensions

This article describes a method for increasing sample load in preparative liquid chromatography by using DMSO as the injection solvent.