Agilent Manuals

An analytical methodology for screening and confirming the presence of 301 pesticides in vegetable samples was developed using the Agilent G6410A Triple Quadrupole Mass Spectrometer (QQQ). Of the 301 compounds, 90% could be identified using this procedure with a limit of detection (LOD) in vegetable matrices of 0.01 mg/kg (ppm) or below, which is the level for baby food and banned substances and is the maximum residue level (MRL) used by the European Union. The analytical performance of the method was evaluated for different types of vegetables (tomato and green pepper), showing little or no matrix effects. Linearity of response over 2 orders of magnitude was demonstrated (r2 > 0.99). The authors of this document are E. Michael Thurman and Imma Ferrer from the Department of Civil, Environmental and Architectural Engineering Center for Environmental Mass Spectrometry at the University of Colorado and Jerry A. Zweigenbaum from Agilent Technologies Inc.

The document introduces the 7th amendment of the European Cosmetics Directive and its requirements for cosmetic manufacturers. It requires manufacturers to indicate the presence of 26 fragrance ingredients in finished cosmetic products if they exceed a threshold of 0.01% (rinse-off) and 0.001% (leave-on). It also discusses the application of Agilent's Deconvolution Reporting Software (DRS) in complex matrices. The software can automatically deconvolute spectra and generate qualification and quantitation reports, increasing the confidence in results and processing efficiency.

This article describes the development of an LC-MS/MS method for the determination of 20-hydroxyecdysone and its metabolites in calf urine, and its application to the control of potential misuse in cattle. The method involves purification on two solid-phase extraction cartridges (SPE C18 and SPE SiOH) and LC-(ESI+)-MS/MS measurements. The sensitivity and specificity of tandem quadrupole MS/MS allowed measurements at trace levels in both spiked and incurred samples. Good linearity was observed for all analytes from 0.12 ng to 12 ng on column.

This file introduces a method for separating a mixture of six B vitamins and vitamin C on the same Agilent ZORBAX Eclipse Plus C-18 stationary phase in three different particle sizes and column dimensions: 5 µm (4.6 × by 150 mm); Rapid Resolution (RR), 3.5 µm (4.6 × 100 mm), and RR High Throughput (RRHT), 1.8-µm (4.6 × 50 mm). A simple phosphate buffer- methanol mobile phase gradient was used. The method was designed to supplement United States Pharmacopeia (USP) methods in which these vitamins are separated singly on different columns by different methods, some involving complex ion-pair reagents. The shorter columns provided more rapid separations with little change in res- olution. All compounds could be separated on the 1.8-µm column in 3.5 minutes. A gain in sensitivity was noted when the column length and particle size were reduced. The HPLC method was applied to the analysis of vitamins in a variety of commercial products, including multivita- mins and various soft drinks. The columns chosen allowed for good separation, but the RRHT column also allowed quick method development without giving up the resolution and sensitivity.

This document introduces a new software and database for rapid detection of Japanese food samples for pesticide residues. The software and database can automatically identify 430 GC/MS data of pesticides regulated by the Japanese government.

A speciation method based on isotope dilution and GC-MS was developed for the determination of methylmercury in fish samples. A spike containing 201Hg-enriched methylmercury was used to determine the methylmercury in tuna samples with excellent results.

A simple and effective method has been developed for the simultaneous determination of the seven tetracycline antibiotic residues in chicken meat.

This Application Note presents a method for rapid determination of carbohydrates in food using capillary electrophoresis with indirect UV-detection. Non-derivatized carbohydrates can rapidly be determined using this method, which is simple and stable, and suitable for application in routine labs.

A rapid screening method for the determination of melamine and cyanuric acid in milk products is developed using Agilent 7890A/5975C GC/MSD along with Agilent J&W HP-5ms GC columns. With the backflushing by capillary flow technologies, this method eliminates the time consumption for column bakeout after elution of target compounds, so as to significantly shorten the GC run time from more than 70 minutes to 14.5 minutes. Good linearity was obtained within the range of 10 to 200 µg/g, with correlation coefficients greater than 0.9996. The recoveries of both target compounds are greater than 95%.

A simple methodology for the measurement of trace and ultratrace metals in edible oils is described.

This rapid method uses the Agilent 6410 Triple Quadrupole (QQQ) with a cation ion exchange column for the liquid chromatography tandem mass spectrometry (LC/MS/MS) analysis of dairy products for melamine. Milk and milk products are prepared with a simple SPE cleanup method employing the new Agilent SampliQ SCX cartridge. The residue is quantified in the multiple reaction monitoring (MRM ) mode. The selectivity of the QQQ can easily eliminate any matrix interferences that may occur in the separation and provide excellent response. The method provides good results with respect to precision, repeatability, and spiked recovery. The recov- ery of 80 ppb and 50 ppb melamine spikes in milk powder using the external stan- dard calculation is 62.5 and 83.4 percent, respectively, and the RSD is less than 3 percent.

This application note describes the use of Agilent ZORBAX Eclipse Plus C18, Eclipse Plus Phenyl-Hexyl, Eclipse XDB-Phenyl and StableBond SB-Phenyl Rapid Resolution columns to analyze nine common food additives using an isocratic solvent system. The mobile phases used include methanol or acetonitrile with 20 mM phosphate buffer at pH 2.5 or 0.2 percent formic acid. While excellent peak shape is found on all columns examined, selectivity and resolution differences are found when comparing C18 and various phenyl columns, especially the Eclipse Plus Phenyl-Hexyl and StableBond SB-Phenyl columns. In addi- tion, selectivity differences and peak shape are preserved even when using a formic acid mobile phase modifier. The use of formic acid would allow verification of unknown materials using mass spectrometry.

A GC/MS method is presented for the quantitative determination and confirmation of melamine residues in milk products.

This document describes a method for distinguishing between DNA derived from the fruits of strawberry and raspberry using polymerase chain reaction (PCR) and the DNA 1000 chip. Using this approach, characteristic profiles from strawberry and raspberry DNA are generated on the Agilent 2100 capillary electrophoresis system, which may prove useful in food authentication studies.