Agilent Manuals

This document describes the analysis method of bitter compounds in orange juice and lists several common bitter compounds. High-performance liquid chromatography (HPLC) is used for analysis, which is suitable for low volatile or thermally unstable compounds. Sample preparation involves protein precipitation using potassium ferrocyanide and zinc sulfate. The results show the presence of bitter compounds such as hesperidin and naringenin in orange juice.

This document describes a method for using HPLC to analyze the quality of vanillin extract. The method uses a gradient elution method using water and acetonitrile as the mobile phases. The method is able to separate a variety of compounds in vanillin extract, including vanillin alcohol, 4-hydroxybenzoic acid, vanillin, ethyl vanillin, and coumarin.

This document introduces the method of analyzing antioxidants in chewing gum.

This paper introduces the application of HPLC in the analysis of acidulants in white wine.

This brief demonstrates the analysis of catechins in tea using the Agilent 1100 Series modules and systems for LC with an electrochemical detector.

This brief demonstrates the analysis of various sugars in candy and juice using PAD with post- column pH–changing. The sugars are separated by both ligand exchange and size exclusion mode.

A new electron capture detector (ECD) for the Agilent 6890 Series gas chromatograph (GC) was used to ana- lyze polychlorinated biphenyl congeners and organochlorine pesticides. The linearity of the 6890 Micro-ECD in the calibration range of 2 to 400 ppb was evaluated. The micro-ECD easily meets the linearity requirements of U.S. EPA contract laboratory programs for pesti- cides. Its limit of detection for these compounds goes down to less than 50 ppt. The micro-ECD also exhibits good reproducibility.

This study analyzed synthetic dyes using ion-pair, reversed phase chromatography on a special base-deactivated HPLC column. This separation mechanism was chosen to reduce tailing effects of highly polar colors. Detection was performed using a new design of diode-array detector based on two lamps — a deuterium lamp and a tungsten lamp. This ensured highest light output at 190 – 950 nm, which resulted in lowest detection limits over the entire wavelength range. It was possible to analyze blue, black or green colors in the low ng range at their absorption maxima of 600 – 700 nm. Complete spectra, feasible from 190 – 950 nm, facilitated identification with an automated library search.

This article describes the analysis of synthetic dyes in food samples using capillary zone electrophoresis with an alkaline phosphate buffer as the background electrolyte. The precision of the method was found to have a relative standard deviation of less than 0.5% for the run-to-run migration times and 2% for the peak areas with buffer replenishment after each run. The detection limit for individual dyes was approximately 1 ng using a 50-µm internal diameter Agilent extended path length capillary. Compounds were detected at different wavelengths (215, 410, 520, and 598 nm) and the identities of the individual dyes were confirmed using peak-purity routines and a UV-Visible spectral library.

Dual-column analysis with HP-35 and HP PAS-1701 columns was used to analyze chlorinated pesti- cides targeted in EPA Methods 608 and 8080 for wastewater and solid wastes. GC parameters were optimized using the Agilent 5890 Series II gas chromatograph (GC) with electronic pressure control (EPC), a dual injector, and a dual electron capture detector (ECD) system. The analysis of 18 pesticides was completed in 12 minutes.

This application note describes the use of capillary electrophoresis to analyze artificial sweeteners and preservatives in drinks. The method does not require a multitude of derivatization chemistries and their separations, and has been successfully applied to both beverages and tablet formulations.

This report describes the analysis of chlorinated pesticides and PCBs using the HP-608 capillary column. The methods are EPA 608, 8080, 8081, and CLP pesticides, which are used to evaluate wastewater and solid wastes. The benefits of splitless and on-column injection techniques using the Agilent 5890 Series II GC with EPC are compared.

Several oxidizable vitamins (vitamin A, B6, C, D3 and E) were analyzed using HPLC and electrochemical detection. Excellent sensitivity was achieved with all vitamins. The minimum detectable level for vitamin A- palmitate was about 80 pg, for β-carotene about 50 pg, for vitamin B6 about 30 pg, for vitamin C below 1 pg, for vitamin D3 about 70 pg and for vitamin E about 30 pg. The optimum potentials were evaluated using an automated increment for the potentials. The reproducibility was tested using vitamin B6 and was found to be 3% RSD of peak height for 100 runs. Due to the high selectivity of electrochemical detection, it was possible to keep sample preparation very simple.

This paper introduces a method for analyzing some anions using HPLC and electrochemical detection.