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Detection and Identification of Chemical Warfare Agents in Environmental Samples

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Detection and Identification of Chemical Warfare Agents in Environmental Samples

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    1. Detection and Identification of Chemical Warfare Agents in Environmental Samples Casper de Boer, Christof Münch, Caroline Münsterer Analytical strategies, 18.10.2011

    2. Outline

    3. Definition Chemical Weapons

    4. Chemical agents as a weapon can be spread by: bomb/explosion crop-dusting plane aerosol device ... ? tequniques of storing and filling are important (mainly used as deterrent weapons)

    5. Dispersal and Fate of Chemical Warfare Agents

    6. Example for chemical warfare agents

    7. Schedules of chemicals

    9. Historical overview Ancient world: salinisation of cropland, poisoned arrows, ... WW I: tear gas, chlorine gas (lung damage), mustard gas (blistering) 1925: Geneva protocol WW II: extensive research on CWs but little use. New agents: tabun, sarin, soman (nerve agents) Vietnam: „herbicidal warfare“ ? use of chemicals to destroy vegetation, food crops (Agent Orange) From late 60s on: towards chemical disarmament 1997: CWC (chemical weapon convention) enters into force ? arms control agreement between (today 188) states which prohibits production, stockpiling and use of CWs

    10. Chemical Weapons Convention CWC

    11. Organization for the Prohibition of Chemical Weapons (OPCW)

    12. Which analytical equipment would you choose for your OPCW designated laboratory with respect to a limited budget of 2 Mio €?

    13. - we must fulfill internationsal standard ‘General requirements for the competence of testing and calibration laboratories’ (ISO/IEC 17025) - national accreditation by an internationally recognized accreditation body - we must regularly participate and perform successfully in inter- laboratory OPCW Proficiency Tests - respect a limited budget

    14. - a huge number of chemicals with different characteristics and unknown concentrations - different and difficults matrices - analysis of each sample by at least two different analytical techniques (one of them has to be a spectrometric technique) - identification must be confirmed by the comparison with reference data.

    28. ->Neutral and weakly basic pesticides, such as organophosphates, triazines, and arylureas, ionized well using either method of ionization, positive APCI generally being the more sensitive. Cationic pesticides (paraquat and diquat) and those that exist predominantly as anions in solution (e.g. sulfonic acids) gave much better responses using ESI (positive or negative). Another factor to consider in the choice of ionization method is the formation of adducts with sodium or other metal ions, in addition to the protonated molecule. Although these may help con?rm the molecular mass, they tend to lower the signal-tonoise ratio of the protonated molecule, resulting in higher detection limits in trace analysis and causing problems in quantitative analysis. Sodium adducts tend to form with positive ESI but not with APCI Coupled to capillary or micro LC, it is more sensitive than particle beam and, like the latter, provides searchable spectra similar to those produced by electron ionization (EI) in gas chromatography/mass spectrometry (GC/MS). It can also operate in CI mode. It is reported to be more widely applicable than APCI, extending the useful range of LC/MS to lower polarity molecules, for example, polyaromatic hydrocarbons, and may be more sensitive than APCI for some neutral analyte Quadrupole mass spectrometers coupled with LC make up a large part of the market. Single quadrupole instruments are limited for unequivocal identi?cation of unknown analytes in that CID is limited to ‘in source’. As already stated, this produces additional chemical noise and does not resolve individual components when coelution from the LC column occurs. For analysis of complex matrices, in which resolution of analytes is poor, these instruments can lead to false positives (10) . Far more ?exible are triple quadrupole systems, in which ions are selectively transmitted by the ?rst quadrupole, CID occurs in the second quadrupole (acting only as a collision cell), and the product ions are separated in the third quadrupole. These systems allow a number of different scanning modes (product ions of selected precursor ions, precursor ions of selected product ions, and neutral loss scans) and can provide very low limits of detection in trace analysis. Unfortunately, triple quadrupole systems are still relatively expensive. Ion-trap systems offer a signi?cantly cheaper and more compact MS/MS capability and they are ?nding increasing use in analytical laboratories. They allow trapping and subsequent CID of selected ions within the ion trap, although scanning is restricted to product ions. Ion traps are generally more sensitive in full scanning mode than quadrupole systems but may be less sensitive in selected ion mode. Although most of the analytical methods used in the authors’ laboratory were developed using a triple quadrupole instrument, most have transferred to an ion-trap LC/MS system without major problems. Expensive high-resolution magnetic sector instruments linked to LC have declined considerably in use other than for research purposes. A->Neutral and weakly basic pesticides, such as organophosphates, triazines, and arylureas, ionized well using either method of ionization, positive APCI generally being the more sensitive. Cationic pesticides (paraquat and diquat) and those that exist predominantly as anions in solution (e.g. sulfonic acids) gave much better responses using ESI (positive or negative). Another factor to consider in the choice of ionization method is the formation of adducts with sodium or other metal ions, in addition to the protonated molecule. Although these may help con?rm the molecular mass, they tend to lower the signal-tonoise ratio of the protonated molecule, resulting in higher detection limits in trace analysis and causing problems in quantitative analysis. Sodium adducts tend to form with positive ESI but not with APCI Coupled to capillary or micro LC, it is more sensitive than particle beam and, like the latter, provides searchable spectra similar to those produced by electron ionization (EI) in gas chromatography/mass spectrometry (GC/MS). It can also operate in CI mode. It is reported to be more widely applicable than APCI, extending the useful range of LC/MS to lower polarity molecules, for example, polyaromatic hydrocarbons, and may be more sensitive than APCI for some neutral analyte Quadrupole mass spectrometers coupled with LC make up a large part of the market. Single quadrupole instruments are limited for unequivocal identi?cation of unknown analytes in that CID is limited to ‘in source’. As already stated, this produces additional chemical noise and does not resolve individual components when coelution from the LC column occurs. For analysis of complex matrices, in which resolution of analytes is poor, these instruments can lead to false positives (10) . Far more ?exible are triple quadrupole systems, in which ions are selectively transmitted by the ?rst quadrupole, CID occurs in the second quadrupole (acting only as a collision cell), and the product ions are separated in the third quadrupole. These systems allow a number of different scanning modes (product ions of selected precursor ions, precursor ions of selected product ions, and neutral loss scans) and can provide very low limits of detection in trace analysis. Unfortunately, triple quadrupole systems are still relatively expensive. Ion-trap systems offer a signi?cantly cheaper and more compact MS/MS capability and they are ?nding increasing use in analytical laboratories. They allow trapping and subsequent CID of selected ions within the ion trap, although scanning is restricted to product ions. Ion traps are generally more sensitive in full scanning mode than quadrupole systems but may be less sensitive in selected ion mode. Although most of the analytical methods used in the authors’ laboratory were developed using a triple quadrupole instrument, most have transferred to an ion-trap LC/MS system without major problems. Expensive high-resolution magnetic sector instruments linked to LC have declined considerably in use other than for research purposes. A

    29. ->Neutral and weakly basic pesticides, such as organophosphates, triazines, and arylureas, ionized well using either method of ionization, positive APCI generally being the more sensitive. Cationic pesticides (paraquat and diquat) and those that exist predominantly as anions in solution (e.g. sulfonic acids) gave much better responses using ESI (positive or negative). Another factor to consider in the choice of ionization method is the formation of adducts with sodium or other metal ions, in addition to the protonated molecule. Although these may help con?rm the molecular mass, they tend to lower the signal-tonoise ratio of the protonated molecule, resulting in higher detection limits in trace analysis and causing problems in quantitative analysis. Sodium adducts tend to form with positive ESI but not with APCI Coupled to capillary or micro LC, it is more sensitive than particle beam and, like the latter, provides searchable spectra similar to those produced by electron ionization (EI) in gas chromatography/mass spectrometry (GC/MS). It can also operate in CI mode. It is reported to be more widely applicable than APCI, extending the useful range of LC/MS to lower polarity molecules, for example, polyaromatic hydrocarbons, and may be more sensitive than APCI for some neutral analyte Quadrupole mass spectrometers coupled with LC make up a large part of the market. Single quadrupole instruments are limited for unequivocal identi?cation of unknown analytes in that CID is limited to ‘in source’. As already stated, this produces additional chemical noise and does not resolve individual components when coelution from the LC column occurs. For analysis of complex matrices, in which resolution of analytes is poor, these instruments can lead to false positives (10) . Far more ?exible are triple quadrupole systems, in which ions are selectively transmitted by the ?rst quadrupole, CID occurs in the second quadrupole (acting only as a collision cell), and the product ions are separated in the third quadrupole. These systems allow a number of different scanning modes (product ions of selected precursor ions, precursor ions of selected product ions, and neutral loss scans) and can provide very low limits of detection in trace analysis. Unfortunately, triple quadrupole systems are still relatively expensive. Ion-trap systems offer a signi?cantly cheaper and more compact MS/MS capability and they are ?nding increasing use in analytical laboratories. They allow trapping and subsequent CID of selected ions within the ion trap, although scanning is restricted to product ions. Ion traps are generally more sensitive in full scanning mode than quadrupole systems but may be less sensitive in selected ion mode. Although most of the analytical methods used in the authors’ laboratory were developed using a triple quadrupole instrument, most have transferred to an ion-trap LC/MS system without major problems. Expensive high-resolution magnetic sector instruments linked to LC have declined considerably in use other than for research purposes. A->Neutral and weakly basic pesticides, such as organophosphates, triazines, and arylureas, ionized well using either method of ionization, positive APCI generally being the more sensitive. Cationic pesticides (paraquat and diquat) and those that exist predominantly as anions in solution (e.g. sulfonic acids) gave much better responses using ESI (positive or negative). Another factor to consider in the choice of ionization method is the formation of adducts with sodium or other metal ions, in addition to the protonated molecule. Although these may help con?rm the molecular mass, they tend to lower the signal-tonoise ratio of the protonated molecule, resulting in higher detection limits in trace analysis and causing problems in quantitative analysis. Sodium adducts tend to form with positive ESI but not with APCI Coupled to capillary or micro LC, it is more sensitive than particle beam and, like the latter, provides searchable spectra similar to those produced by electron ionization (EI) in gas chromatography/mass spectrometry (GC/MS). It can also operate in CI mode. It is reported to be more widely applicable than APCI, extending the useful range of LC/MS to lower polarity molecules, for example, polyaromatic hydrocarbons, and may be more sensitive than APCI for some neutral analyte Quadrupole mass spectrometers coupled with LC make up a large part of the market. Single quadrupole instruments are limited for unequivocal identi?cation of unknown analytes in that CID is limited to ‘in source’. As already stated, this produces additional chemical noise and does not resolve individual components when coelution from the LC column occurs. For analysis of complex matrices, in which resolution of analytes is poor, these instruments can lead to false positives (10) . Far more ?exible are triple quadrupole systems, in which ions are selectively transmitted by the ?rst quadrupole, CID occurs in the second quadrupole (acting only as a collision cell), and the product ions are separated in the third quadrupole. These systems allow a number of different scanning modes (product ions of selected precursor ions, precursor ions of selected product ions, and neutral loss scans) and can provide very low limits of detection in trace analysis. Unfortunately, triple quadrupole systems are still relatively expensive. Ion-trap systems offer a signi?cantly cheaper and more compact MS/MS capability and they are ?nding increasing use in analytical laboratories. They allow trapping and subsequent CID of selected ions within the ion trap, although scanning is restricted to product ions. Ion traps are generally more sensitive in full scanning mode than quadrupole systems but may be less sensitive in selected ion mode. Although most of the analytical methods used in the authors’ laboratory were developed using a triple quadrupole instrument, most have transferred to an ion-trap LC/MS system without major problems. Expensive high-resolution magnetic sector instruments linked to LC have declined considerably in use other than for research purposes. A

    30. Question 3: You can hire employees for your lab. What skills, knowledge and educational background would you look for?

    31. education: university degree in chemical engineering or chemistry from recognised university

    32. Question 4: What is a mandatory and fundamental prerequisite not yet covered? How can you fulfill this prerequisite and what are the problems you will encounter? How can you solve them?

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