Said to be the first method for determining total sulphur and sulphur species in gasoline at levels that meet upcoming US and EU regulations
Agilent Technologies has announced a method for characterising sulphur in reformulated gasoline using gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS).
This method is said to be the first available technique that can measure both individual sulphur species and total sulphur at the lower levels required by upcoming US and EU regulations.
It quantifies individual sulphur species in the low parts-per-billion (ppb) range and total sulphur 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 sulphur pollution as a contributing factor to a host of environmental and health problems.
Sulphur 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.
Sulphur 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 sulphur in motor fuels.
In 2004, the US Environmental Protection Agency will begin phasing in new guidelines creating an average sulphur standard of 30 ppm for motor fuels.
The EU recently set new regulations requiring the full market availability of sulphur-free fuels (containing less than ten parts per million sulphur) by 1 January 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 reportedly displayed excellent sensitivity compared with traditional detection techniques that use sulphur chemiluminescence, flame photometric or atomic emission detectors.
Individual sulphur species such as thiophene and 2-methylthiophene were detected at 3 to 10ppb, with total sulphur detected at approximately 0.1 to 0.5ppm.
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.
Further information is available by requesting Agilent application note 'Quantification and characterisation of sulphur in low sulphur reformulated gasolines by GC-ICP-MS," Agilent publication number 5988-9880EN.
This note is available without charge from any Agilent sales office or its website.
