Agilent Manuals

This application demonstrates a reversed-phase separation using high-organic concentration (>90% methanol) on a ZORBAX XDB-C8 column. By using reversed-phase chromatography for water-soluble and fat-soluble vitamins, labs requiring both assays can now minimize changeover time.

This document discusses the effect of mobile-phase solvent strength in the separation of mono- and disaccharides. Good resolution of various sugars can be achieved using a ZORBAX NH2 column. The retention of sugars increases with increasing organic content in the mobile phase.

This document introduces the results of an experiment on using ZORBAX Sil for high-performance liquid chromatography separation of vitamin A isomers (retinal isomers).

This document introduces a high-efficiency and high-speed separation method for natural anthocyanins. The method uses ZORBAX StableBond SB-C18 columns and phosphoric acid mobile phase, which can achieve high-efficiency separation of more than 25 anthocyanins.

High-Speed Separation of Water-Soluble Vitamins with Ion-Pairing Chromatography

This document describes the use of the USP 23 method to separate water-soluble vitamins using StableBond columns, which provide long-term stability and reliability.

Separation of Water-Soluble Vitamins Using Reversed-Phase Chromatography

Two retention time locked methods for the analysis of essential oil compounds are described

This document describes the successful analysis of carbamates (a class of highly effective insecticides) and phenyl ureas (a class of herbicides) using liquid chromatography/mass spectrometry with electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photo ionization (APPI) sources. APPI and APCI exhibited lower background signals and fewer background peaks than ESI. Phenyl ureas, in general, exhibited better signal-to-noise ratios (S/N) from APCI or APPI than from ESI. However, it was just the opposite for carbamates. The S/N was better from ESI than from APCI or APPI. A small amount of post-column acetone was needed in the APPI source as a photoionizable dopant for charge transfer to the analyte.

This document describes an analytical method for the active ingredient in an agricultural fungicide formulation. Liquid chromatography is used to easily separate and detect the active ingredient without extensive sample preparation.

This application note details the relative merits of two techniques for the analysis of organotin compounds: gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS) and high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS).

Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine lead (Pb) isotope ratios in Dan-shen, a type of herb used in Traditional Chinese Medicines (TCM), and in water and soil samples all taken from the same geographical location.

The document describes the methods of isolating penicillins from the culture medium of certain fungi and synthesizing other penicillins through semisynthesis or precursor-indicated biosynthesis. Penicillin inhibits the polymerization of murin, which is responsible for the stability of the bacteria's cell wall. Due to the toxicity of many antibacterials, various countries regulate the level of antibacterial residues in agricultural, veterinary, dairy, and meat-based food products. The HPLC analysis in the document demonstrates the separation of four common antibacterial drugs with penicillin-like structure on an SB-C18 reversed phase column.

This document discusses the natural occurrence of tetracyclines, their use in human and veterinary medicine, and their use as nutritional antibiotics in pig and poultry farming. The document also demonstrates the HPLC separation of antibacterial drugs with a tetracycline structure using a Zorbax SB-C18 reversed phase column and an alternative mobile phase to TFA. The HPLC method provides an easy, reliable, and precise analysis of the antibacterial drugs.

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the simultaneous determination of the metabolites of four nitrofuran antibacterial drugs in chicken tissues: furazoli- done, furaltadone, nitrofurazone, and nitrofurantoin. Sample clean-up and analyte enrichment were performed by liquid-liquid extraction with ethyl acetate followed by solvent washing, hydrolysis of the protein-bound drug metabolites, and derivatization with 2-nitrobenzaldehyde (2-NBA). ESI parameters were optimized, and the chro- matographic separation of all metabolites was examined. Each metabolite produced a simple mass spectrum con- taining a strong signal corresponding to [M+H]+. Metabolite calibration curves, in the 0.25 to 1 ng/mL range, exhibited correlation coefficients greater than 0.999. The limit of detection (LOD) for each analyte ranged from 0.02 to 0.06 ng/mL. Introduction The four drugs shown in Figure 1, furazolidone, furaltadone, nitrofurazone, and nitrofurantoin, belong to the group of nitrofuran antibacterial drugs. These drugs have been widely used as feed additives to prevent bacterial enteritis by Escherichia coli and Salmonella in cattle, fish, swine. The main metabolites of these drugs are 5-methyl-5-nitro-2-furaldehyde and 5-amino-5-nitro-2-furaldehyde, which are produced by the hydrolysis of the protein-bound drug metabolites.