Agilent Manuals

A single method for analyzing aromatic solvent purity is described. This Unified Aromatic Solvent application consolidates ten separated American Society of Testing and Materials methods into an easy-to-use gas chromatography method. An Agilent 6820 gas chromatography system configured with split/splitless inlet and flame ionization detector is used. The successful use of nitrogen as a carrier gas for this application is also demonstrated.

A two-dimensional gas chromatography system using a simplified Deans switch design is used for the analysis of trace (mg/kg) thiophene in benzene. This system uses two GC columns of different selectivity, INNOWax and PLOT Q, to completely separate the thiophene from the interfering sample matrix. Because of this high resolution, standard flame ionization detectors can be used in place of more expensive and complex sulfur selective detectors. The system provides precise qualitative and quantitative analyses results that are in agreement with those using sulfur selective detectors. This versatile system can also perform a standard American Society for Testing and Materials benzene purity analysis at the same time the thiophene measurement is made.

This paper presents a two-dimensional gas chromatography system based on a simplified Deans switch design, used to analyze the alcohol content in denatured fuel grade ethanol. The two-dimensional gas chromatography application completes this analysis 10 times faster than the standard ASTM D5501 method without the use of cryogenic oven cooling. This easy-to-use system also provides high qualitative and quantitative precision for this measurement.

This application note examines the quantification of total sulfur levels (using compound independent calibration) and sulfur speciation in reformulated gasoline.

The enhanced inertness of the new 5973 inert MSD improves analysis of trace level volatile sulfur compounds. When operated in scan or selected ion monitoring mode, excellent sensitivity, selectivity, and peak symmetry are obtained for active compounds. Eight volatile sulfur species are used to demonstrate these attributes in a variety of hydrocarbon matrices. The system is well suited for the characterization of fuel feedstocks and basic petrochemicals, where impurities can poison critical catalytic processes or affect product quality.

This application describes the improved performance for the analysis of aromatics in gasoline by ASTM Method D5769 using the Agilent 5973 inert gas chromatography/mass spectrometry (GC/MS) system.

A two-dimensional gas chromatographic method (GC-GC) is described for the analysis of trace benzene in styrene. This method uses the Agilent 6890N GC system equipped with a Deans switch device. The method can be used in a prefractionator mode to analyze trace benzene in styrene according to the proposed ASTM method [1]. It can also be used in a heart-cutting mode to transfer more precisely just the benzene peak from the primary column to the sec- ondary column. The Agilent 6890N electronic pneumatics control and flow calculation software are used for setting up the precise flows and pressures required. Excellent calibration and sensitivity of this system is demonstrated in both prefractionator mode and heart-cutting mode, and the interference can be greatly reduced by the heart-cutting.

This application note describes a method for determining benzene, toluene, ethylbenzene, p/m-xylene, o-xylene, C9 and heavier aromatics, and total aromatics in finished gasoline using the Agilent 6820 GC System.

The document describes an analytical method for the determination of ethers and alcohols in gasolines using the Agilent 6820 gas chromatography system. This method utilizes a 10-port switch valve and two columns. The specific compounds determined include methyl tert-butylether (MTBE), ethyl tert-butylether (ETBE), tert-amylmethylether (TAME), diisopropylether (DIPE), methanol, ethanol, isopropanol, n-propanol, isobutanol, tert-butanol, sec-butanol, n-butanol, and tert-pentanol. 1,2-dimethoxyethane (DME) is used as the internal standard for quantitative analysis. The Agilent 6820 GC is used to run ASTM Method D4815 for determining oxygenates in gasoline.

This application describes a method for determining the content of benzene and toluene in motor and aviation gasoline using an Agilent 6820 gas chromatograph (GC) system and ASTM Method D3606. The method uses an internal standard to calculate the concentration of each component and employs Agilent Cerity NDS software for GC control and data analysis. This application demonstrates that calibration and precision meet or exceed the ASTM D3606 specifications.

A new method for the analysis of trace methanol in crude oil samples was developed based on two-dimensional heart-cutting gas chromatography. The method was tested on an Agilent 6890N GC system equipped with a new gas phase microfluidic Deans switch that improved the performance of heart-cutting two-dimensional gas chromatography. The results obtained with this method exceeded the performance requirements of ASTM D7059 for the analysis of methanol in crude oil.

A rapid simulated distillation method is described for analysis of petroleum fractions boiling within the range of ASTM D2887. The method employs an Agilent 6890N gas chromatograph equipped with a split/splitless inlet, flame ionization detector (FID), oven insert, and 3-meter 180-µm id capillary column. Compared to conventional ASTM D2887, the accelerated method yields run times at least two times faster. It yields results comparable to traditional D2887, and agrees with the guidelines of ASTM method D2887 based on published results for the reference gas oil (RGO).

The Agilent 7500ce ICP-MS is shown to be an excellent analytical tool for the elemental analysis of gasoline. It offers the best detection limits of any multi-element tech- nique and a full elemental analysis suite that takes less than 5 minutes to acquire. The Octopole Reaction System (ORS), integral to the 7500ce, ensures that a single method and set of conditions can be used to directly determine all elements of interest in the sample. Comparison data for selected elements in both gas mode and no-gas mode highlight the effectiveness of the ORS for interference removal. Results showing the excellent long-term stability of the 7500ce ORS are also given.

This Application Note demonstrates how a daily throughput of far more than 1000 samples can be achieved together with full spectral data acquisition and accurate mass information with close to FT-MS mass accuracy using the Agilent 1200 Series Rapid Resolution LC system and the Agilent 6210 TOF MS.