Agilent Manuals

This application note details how the Agilent 2100 Bioanalyzer was used in polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) fragment analysis for fish species identification. A 464bp cytochrome-b target sequence, found in all vertebrate fish, was first amplified and then digested with restriction enzymes. The fragments were resolved on the DNA 500 LabChip®, allowing simple comparison with authentic species profiles due to the accuracy of fragment size determination. Use of the Bioanalyzer offered significant benefits over traditional gel electrophoresis and DNA staining techniques for PCR-RFLP fragment analysis.

This paper describes the configuration and operation of a combined liquid chromatography/mass spectrometry (LC/MS) system for the identification and isolation of DSP-toxins. In the analytical mode, okadaic acid (OA) and dinophysistoxin-1 (DTX-1) are more selectively and sensitively monitored when compared to LC with fluorescence detection. With less sample preparation, the detection limits are decreased by a factor of 3–5, depending on the matrix. In semipreparative mode, OA and DTX-1 could be isolated from crude extracts of Prorocentrum lima algae using mass-based fraction collection with a purity >98%. Due to this method, reference standards of DSP toxins are now commercially available.

This document describes a method for separating major classes of soybean phospholipids from a crude mixture using a matched set of columns, normal phase conditions, and a small amount of volatile salt added to the mobile phase, under both analytical and preparative conditions. However, at higher concentrations of phosphatidylcholine, two distinct peaks were observed, whose areas changed with the mass injected. Mass spectrometry confirmed that these two peaks are the same or very similar.

This document describes a method for measuring chromium content. This method can separate and measure Cr(III) and Cr(VI), and provide an indication of the toxicity of Cr content in a sample.

Identification of Unknown Pesticides in Food Using Both LC/MSD TOF and Ion Trap MSn

This article describes a GC/MS system for the rapid screening of foodstuffs for chemical contaminants with a special emphasis on pesticides, organophosphorus, and organosulfur compounds.

The Agilent Technologies mass selective detector (MSD) coupled with deconvolution reporting software (DRS) provides additional powerful data processing capabilities to the MSD ChemStation software. Extensive data shown in this report supports the high confidence level that an analyst can have in results rapidly produced by the DRS.

A financial model was developed to help the metals labo- ratory using graphite furnace atomic absorption and inductively coupled plasma optical emission spectroscopy calculate the potential savings by switching to inductively coupled plasma mass spectrometry. Results based on several typical laboratory examples are presented.

This document describes a method for studying fifteen of the most common and important organophosphorus pesticides (OPs) using the Agilent 6820 gas chromatograph (GC) equipped with the new nitrogen-phosphorus detector (NPD). The 6820 GC-NPD demonstrated good linearity for concentrations of pesticides range from 1 to 500 ng/mL (R2 >0.999) for most compounds. All OPs produced high signal-to-noise ratios for splitless injections at 10 ng/mL (ppb) concentrations with the NPD detector. Instrumental limits of detection for most OPs studied were at low or sub-ppb concentrations. This suggests the 6820 GC with an NPD is well suited for OP pesticide residue determinations in foods, water, or other samples.

This document describes the use of Agilent 6820 gas chromatograph (GC) with micro-electron capture detector (µECD) to analyze organochlorine and pyrethroid compounds. The sensitivity provided by µECD was much better than the requirements of the routine pesticide residue analysis.

According to The Pesticide Manual, more than 700 pesticides are currently approved for use around the world. Some of these pesticides that have been discontinued still persist in the environment and can bioaccumulate in flora and fauna. Many pesticides and their degradation products can be found at trace levels in food and beverages, soil, water, air, aquatic and terrestrial flora and fauna, as well as in human blood, adipose tissue, and breast milk. The World Health Organization has classified pesticides into five groups based on their acute toxicity to humans. Current analytical methods target comprehensive pesticide screening using GC/MSD with Deconvolution Reporting Software Application to track pesticide distribution in the environment and ensure a safe food supply.

This application note outlines the theory of interference removal using the ORS, the design enhancements employed, and the typical performance of the Agilent 7500ce.

An LC/MS/MS method was developed for the qualitative and quantitative measurement of nitrofuran metabolites in chicken and shrimp using the Agilent LC/MSD XCT Ion Trap. The limit of quantitation for all four nitrofurans investigated easily met the specified European Union Minimum Required Performance Level of 1 µg/kg and ranged from 0.125 µg/kg to 0.5 µg/kg. Nitrofuran antibiotics are widely used for the treatment of infectious diseases in cattle, pigs, shrimp, and poultry. Due to their rapid metabolism nitrofuran parent substances are not suitable for monitoring and typically their metabolites are analyzed. A liquid chromatography /mass spectrometry/mass spectrometry (LC/MS/MS) method was developed for the sensitive, qualitative, and quantitative analysis of four derivatized nitrofuran metabolites found in shrimp and poultry.