Agilent Manuals

This document introduces the method of using capillary electrophoresis to analyze artificial sweeteners and preservatives in drinks. The method has been successfully applied to both beverages and tablet formulations.

This article describes the analysis of flavonoids in plant extracts using CE-MS. The combination of electrospray ionization mass spectrometry (ESI-MS) with capillary electrophoresis allows for specific identification of analytes in complex matrices. The analysis of flavonoids from orange extracts is presented as an example, highlighting the specificity and sensitivity of the method. Monitoring the presence of these flavonoids in orange juice can be used to assess the quality of the product.

A method for determining the residues of melamine in milk powder and egg

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.

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

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.

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.

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

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%.

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

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.