Post on 11-Jan-2017
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Quantification of the concentration of VOCs in gasoline and diesel
www.estcal.comwww.estcal.comElectronic Sensor Technology, Inc.
Quantification of the concentration of VOCs in gasoline and diesel
www.estcal.comwww.estcal.comElectronic Sensor Technology, Inc.
4 News that have shocked us in the past!
• Fuel contamination incident in Bangor, County Down lead Tesco to pay the claims of about £8m.
• ASDA sent cheques to about 3,000 customers who collectively claimed £1.4m in compensation.
• In 2009, Fatty Acid Methyl Ester, a harmful component for engines found in jet fuel of U.S Air Force’s C-130 USAF.
• Fleet Readiness Center (FRC) East discarded about 12,000 gallons of fuel in December, 2014.
Fuel contamination is creating major problems for the globe
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The increasing number of fuel contamination cases every year arises a need for a technology to detect impurities in the fuel.
Introducing…zNose®
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7 Unique features of EST zNose®
Uses Surface Acoustic Wave (SAW) sensor and
ultra-fast Gas Chromatography (GC)
technology.
Rapidly provides complete
chemical profile.
Software of zNose® includes expandable library
of over 700 chemicals & odor signatures.
Operates within a wireless network.
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4 steps to quantify the Chemistry of Gasoline Vapors!
Step 1 -Ambient air (vapor) is first sampled
and organic vapors collected on the trap
that acts as a pre-concentrator.
Step 2- The trap is switched into the
helium section where the collected organic
compounds are injected into flowing helium gas.
Step 3- The organic compounds pass through a
capillary column with different velocities and thus
individual chemicals exit the column at specific
times.
Step 4- As they exit the column they are
detected and quantified by a solid
state detector.
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6 Samples of Pemex gasoline (87 and 92 octane) & 5 samples of diesel were taken from various service stations across US and subjected to a 4-step GC
method.
Testing Gasoline and Diesel Samples from service stations!
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4-step GC method
Step1: Sample Preparation Fully vaporized samples and headspace vapors of gasoline and diesel collected.
Step 2: Sample Pre-concentration Time: Required sample volume of 1-0.5 milliliter from the concentration of vapor samples from gasoline and diesel.
Step 3 - Column Ramping: Used a db624 column and temperature ramping rates varied from zero (isothermal) to as high as 18o C/second.
Step 4 - Detector Response: Detector temperature of 10o C used for optimum response to the most volatile compounds, such as benzene.
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• Calibration standards made by injecting known concentrations of benzene, toluene, ethylbenzene, o-xylene, and n-alkanes into septa sealed 40 milliliter vials and 250 milliliter bottles.
• Vapor standards used to verify system linearity and to provide reference retention times for indexing peak retention times.
• Standard deviation of replicate measurements using vapor standards was typically 1-5%.
• Using BTEX calibration standards used to test system linearity for vapor concentrations up to approximately 50 ppm.
4 Key Matrices to Set Calibration Standards
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Email us at:
Contact us
italib@estcal.com
We are keen to tell you more about EST zNOSE®