Agilent Manuals

1,12-Dodecyldiphosphonic acid is a phosphorous acid, is polar and has surfactant properties. It consists of two polar heads joined by a non-polar, twelve carbon chain. Agilent Technologies, Inc. published a application note to demonstrate how the Agilent ELSD can be used to analyze 1,12-dodecyldiphosphonic acid.

This document introduces a liquid chromatography technique for analyzing polymers that can detect very small differences in the chemical structures of polymers. This technique uses critical point mobile phases and is more sensitive to small differences in polymer structure than conventional interactive chromatography techniques, making it a more suitable method for these analyses.

This application note describes the use of ion-pair reversed-phase chromatography for the separation of de-protected oligonucleotides, focusing on media and ion-pair requirements.

This document describes the optimization of peptide separations using PLRP-S reversed-phase material in acidic and basic conditions by HPLC with ELSD.

This paper presents a method for analyzing common aerosol propellants and an alternative blending technique for high concentration standards. The analysis was performed using an Agilent Technologies gas chromatograph configured with an automated 6-port gas sample valve, a split injection inlet, an HP-PLOT Q capillary column, and a thermal conductivity detector. Six methods were configured with six different split ratios to create a six-point calibration curve for each standard. Additionally, a method is provided to dynamically dilute samples when a multipoint calibration is desired across a narrow calibration range from a single standard.

This report discusses the findings of an investigation into alternative solvents for the analysis of peptides on a SepTech ST150 10-C18

This application note describes a fast reversed-phase HPLC method for the determination of aspirin, salicylic acid and phenacetin. The method uses a highly retentive polymeric reversed-phase column (PLRP-S 100Å) and gradient elution. The method provides excellent separation of the analytes, and can be completed in less than 10 minutes. The method is also highly reproducible and stable.

This article introduces the use of PL-SAX strong anion-exchange HPLC columns for high-resolution separations of oligonucleotides. After deprotection of the oligonucleotide product, hydrophobicity-based separation can be performed, followed by anion-exchange HPLC for further resolution. The experimental results show that the PL-SAX column can achieve separation of n-1 from n.

This application note describes a method for characterizing xylooligosaccharides derived from xylan using aqueous SEC with HPLC. The method provides accurate separation and characterization of oligomers with similar molecular weights, with excellent sensitivity and stability.

This application note demonstrates the analysis of tertiary-butyl mercaptan (TBM) in a natural gas matrix using the Agilent 490 Micro GC. The dimensions and instrument conditions for the column channel used in this application note, a CP-Sil 13 CB, clearly shows the separation of TBM from the other compounds in the natural gas sample. The advantage of the Agilent 490 Micro GC, in combination with the CP-Sil 13 CB column channel, is the ease of use and the speed of analysis. Tertiary-butyl mercaptan elutes just before 60 seconds and the total analysis time is only 100 seconds. The Agilent 490 Micro GC is a rugged, compact and portable lab-quality gas analysis platform. When the composition of gas mixtures is critical, count on this fifth generation micro gas chromatography.

This application note describes a method for the analysis of dialkyl phthalates using an Agilent PLgel 5 µm 50Å column using gel permeation chromatography.

This document introduces the application of Agilent PLgel column and GPC/SEC technology in oligomer separation, as well as the effect of particle size on separation effect

Effect of pH on Protein Size Exclusion Chromatography Application Note Introduction Determination of protein structure is key to understanding the function of many proteins. Molecule size is an indicator of structure and provides information on the quaternary structure of the protein. Many proteins undergo profound conformational changes in different solution conditions, with the most extreme being denaturation. Similar structural modifications may occur as a function of ionic strength, pH, temperature and changes in various other solution conditions. Proteins comprise amino acids, some of which have polar side chains or contain acidic or basic groups. At the isoelectric point, the protein is uncharged and charge repulsions of similar functional groups will be at a minimum, allowing aggregation to take place. Many proteins precipitate under these conditions, and even for proteins that remain in solution at their isoelectric point this is the pH of minimum solubility. At physiological pH most proteins are above their isoelectric point and have a net negative charge. A pH lower than the isoelectric point causes protonation of acidic groups and a net positive charge on the protein. In each case, the like- charges formed repel each other, reducing the likelihood of protein aggregation. However, in areas of larger charge density the intramolecular repulsion can lead to destabilization of the protein tertiary structure and subsequent unfolding. In some cases, this unfolding may lea...

This document describes the use of tetracyclines and the USP method1 for the analysis of the compound

This application note describes a trial of the purity and stability of stored L-ascorbic acid powder samples from four different manufacturers, and assesses degradation compounds and/or precursors from the production process.