Agilent Technologies introduces first method for determining total sulfur and sulfur species in gasoline
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Agilent Technologies Inc. (NYSE: A) today announced a method for characterizing sulfur in reformulated gasoline using gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS). This method is the first available technique that can measure both individual sulfur species and total sulfur at the lower levels required by upcoming U.S. and EU regulations. It quantifies individual sulfur species in the low parts-per-billion (ppb) range and total sulfur at less than one part per million (ppm).
The sensitivity of the method provides scientists in the environmental and hydrocarbon processing industries with comprehensive information for regulatory compliance and process control.
Research has implicated sulfur pollution as a contributing factor to a host of environmental and health problems. Sulfur dioxide is a precursor to acid rain, which increases the acidity of soils, lakes and streams; damages plant and animal life; accelerates the corrosion of buildings and monuments; and reduces visibility. Sulfur pollution also poses a risk to human health, as long-term exposure can lead to respiratory and cardiovascular illness.
As a result, the United States and the European Union have mandated increasingly lower permissible levels of total sulfur in motor fuels. In 2004, the U.S. Environmental Protection Agency will begin phasing in new guidelines creating an average sulfur standard of 30 ppm for motor fuels. The EU recently set new regulations requiring the full market availability of sulfur-free fuels (containing less than 10 parts per million sulfur) by Jan. 1, 2005, with the phase-in to be completed by 2009.
This method uses an Agilent 6890 GC with split/splitless injector coupled to an Agilent 7500a ICP-MS with GC-ICP-MS interface. The method displayed excellent sensitivity compared with traditional detection techniques that use sulfur chemiluminescence, flame photometric or atomic emission detectors. Individual sulfur species such as thiophene and 2-methylthiophene were detected at 3 to 10 ppb, with total sulfur detected at approximately 0.1 to 0.5 ppm.
Because of the size and robustness of the ICP-MS plasma, this method virtually eliminates significant analyte signal suppression due to coeluting hydrocarbons. As a result, the GC separation does not need to be compromised to separate analyte and hydrocarbon peaks, and much faster run times can be achieved. Total run time for this method was 12 minutes, compared to the 25 to 30 minutes required when using conventional detectors.
Additionally, since ICP-MS is a scanning, elemental detector, this method can be used for simultaneous detection of other volatile organometallic species in fuels. This can provide important additional information about fuel quality and process control without added investment in time or equipment.