Detection of toxics in the workplace by GC/PID
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The document discusses the detection of toxic chemicals in the workplace using portable gas chromatography and photoionization detectors (PID). It highlights the importance of these tools for first responders in situations such as chemical spills or terrorism-related events, with capabilities for measuring contamination levels in air, water, and soil. The document also details the specifications of various portable GC models and their sensitivity in detecting toxic compounds, emphasizing their role in maintaining worker safety and environmental protection.
Detection of toxics in the workplace by GC/PID
- 1. Detection of Toxics in the Workplace by GC/PID By: J.L.Maclachlan and J.N.Driscoll, PID Analyzers, LLC Sandwich, MA #Pittcon Paper 1650-1
- 2. Any chemical which, through its chemical action on the human body, can cause death, temporary incapacitation, or permanent harm. Hazmat- Accidental Chemical spills-Truck or railcar carrying chemicals, gasoline etc. Workplace during manufacturing Terrorism- Subway, Stadium, Public gathering AirToxics- Area surrounding a chemical manufacturing plant What are chemical toxics and where can they be encountered?
- 3. Rail Car or ChemicalTanker Spill Problem The spill from an overturned railcar or tanker could be from 5,500-11,000 gallons of liquid cargo. In many cases, the chemical spilled has been liquid Cl2 or NH3.These compounds have been used in the middle east as chemical agents and are quite toxic (Immediately Dangerous to Life or Health (IDLH Cl2 is 10 ppm) The problem is how to protect the first responders, evacuate the people, ©cylonphoto - Can Stock Photo Inc.
- 4. Portable GC with PID: AVersatileTool for Chemical Spills A portable GC with a PID is a very useful tool for first responders to provide both worker protection, protection of people in the immediate area and to determine the extent of contamination on the land and in any nearby water sources
- 5. PHOTOIONIZA TION: R + hV => R+ + e- Where: R is any molecule with an Ionization Potential of 10.6 eV or less hV is a high energy photon (10.6 eV) The R+ ions are collected in an ionization chamber adjacent to the UV lamp; the current is proportional to concentration over a range of 10⁷
- 6. EPA list of 25 Most Common Organic AirToxics
- 7. Toxics that a first responder might encounter For large releases, a command center would be setup and a mobile van with portable instrumentation such as 4 gas meters, PID’s, FID’s and portable GC would be employed to protect the health and safety of the first responders as well as the people in the immediate area. The PID/GC could be used to detect levels of contamination of the spilled compound(s) and to determine the extent of contamination of the air, water and soil If the spill was TCE or PCE, then the GC/PID would provide the following data for this hazmat application First Screening Tools: 4 gas meters/PIDs, FIDs OSHA Standards 29 Code of Federal Regulations, part 1910.120 calls for assembly of a hazmat team
- 8. Chromatogram of 4.2 ppb of TCE & PCE
- 9. OSHAToxics and IDLH OSHA Controlled Chemicals with low IDLHValues
- 10. Chemical Reaction Vessels: Portable PIDs can detect ppb levels of most organic compounds Although a 4 gas meter is designed for confined space entry, the portable GC/PID is a very sensitive detector and can alert the operator to ‘unexpected’ IDLH chemicals that might be present at the time of inspection; some species that the combustible gas
- 11. List of Ionization Potentials & PID Response The PID responds to most organic compounds (not CH4) and certain inorganic compounds like: H2S, Cl2, Br2, NO2, O3, PH3. Responds to alkanes > C3 Responds to all alkenes with higher sensitivity Responds to all aromatic HCs with even greater sensitivity
- 12. PID Characteristics The PID is one of the most sensitive GC detectors available It is 50 to 100 x more sensitive than the FID for aromatic HC’s It has low or sub ppb detection limits for many compounds It (10.6 eV lamp) responds to any compound with IP < 10.7 eV It has a dynamic range> 107 It responds to VOC’s and inorganic compounds
- 13. NEW PHOTOIONIZATION DETECTOR A new version of the PID has been introduced- a windowless version that can use an argon discharge and can detect compounds with IP’s up to 11.8 eV By changing the discharge gas to helium, this becomes a universal detector with a photon energy of 20.2 eV Ionization detectors, in general, are the most sensitive detectors for GC
- 14. Different Types of GC Setups Produce Varying Separations with GCs
- 15. Portable GC Model 121 Specifications Dimensions: 8” L x 2.75 “ W x 41/2 “ H Weight: 3 # GC + 1.5# carrier gas # of components 1-6 (max) Columns micropacked or 15/30M x 0.32mm capillary column (3” Diam., thick film) Detector: single Tank: Clips to unit Detectors-3-sealed window PID w/ 10.6 eV (available now), flame ionization (available 9/2017), Thermal conductivity detector (available January 2018) Operating time: 6-8 hours Detection limit benzene: sealed PID lamp (10.6) <5 ppb; w concentrator < 500 ppt Display: 3.5” touch screen
- 16. Portable GC 312 Specifications Dimensions: 18.75” L x 13.75 “ W x 7.5 “ H Weight: 27 pounds total # of components 30 (max) Columns micropacked or 15/30M x 0.32mm capillary column (3” Diam, thick film) Detectors: one or two Tank: inside Detector-5-sealed window PID (10.6 eV), windowless PID, Far UV detector, Thermal conductivity detector Operating time: 6-8 hours Detection limit benzene: sealed PID lamp (10.6) -1 ppb; w concentrator < 500 ppt Display: 9’ touch screen- NEW Windows® 10 OS- NEW Low power faster PC- NEW! Availability: now
- 17. Toxics & Homeland Security Chemical and Biological Agents could be used by terrorists to target our embassies and/or military bases in foreign countries. The agents are more difficult to make and many of the chemicals used in their preparation are regulated by the government On March 20,1995 Tokyo Japan, sarin was released in subway by Aun Shinrkro The University of Helsinki has evaluated the response of chemical agents with our portable GC/PID.
- 18. Chromatograms of Lewisite with a GC PID 4 ng Lewisite 0.4 ng Lewisite Here’s some chromatograms we can share
- 19. Chromatograms of ChemicalAgents 4 ng CW Agents 0.4 ng CW Agents GB = Sarin GC= Somin GA = Tabun H= Mustard Gas
- 20. necessary in a plant or at the fenceline? Air for PEL, STEL for worker protection (OSHA) Leaks to reduce fugitive emissions (EPA/OSHA) Fenceline (EPA) Process or Stack (EPA) Water (EPA)
- 23. GC 121 benzene + alkanes No PID response from C1 to C4 alkanes 100 ppb bz + 500 ppb hexane 100 ppb bz + 500 ppb C5,C6, C8
- 26. ppb BTEX direct inj. with PeakWorks™/Windows® 10 OS Software
- 27. Benzene Fenceline Monitoring at a Refinery via GC/PID
- 28. Sandwich, MA
- 29. The PID is one of the most sensitive detectors available for many toxic compounds with detection limits in the low or sub ppb range.The portable GC 312 or GC121 with a PID can be equipped with a battery operated concentrator to achieve detection of ppt levels of toxic compounds in the field for emergency hazmat, homeland security and/or fenceline monitoring applications. The use of Bluetooth® communications allows remote viewing of the GC data outside the contaminated area. GC systems should be optimized for their intended applications to achieve the best chromatographic results. Conclusions
- 30. Connect with me at Pittcon Booth 944