1Clicker Review Questions for 1stMidtermCHEM-51813-Oct-2006Clicker question on PDFsThe probability that X = 1 for the normaldistribution in green(zero mean, unit std. dev.) is:A. About 0.2B. 2000C. ZeroD. All of the aboveE. I don’t knowGaussianPDFs2Clicker question on PDFsThe probability that X = 1 for the normaldistribution in green(zero mean, unit std. dev.) is:A. About 0.2B. 2000C. ZeroD. All of the aboveE. I don’t knowGaussianPDFsQ: What function(s) do the magnets in an electron ionization source serve?A. They reject positively formed ions, allowing only negatively charge ions out of the sourceB. They increase the electrons path length, increasing ionization efficiencyC. They increase the analytes path length, increasing ionization efficiencyD. Both B and CE. A, B and CBarry Mather3Q: What function(s) do the magnets in an electron ionization source serve?A. They reject positively formed ions, allowing only negatively charge ions out of the sourceB. They increase the electrons path length, increasing ionization efficiencyC. They increase the analytes path length, increasing ionization efficiencyD. Both B and CE. A, B and CBarry MatherQ: What statement(s) are true in regards to Quadrupole Ion Traps?A. They have the same stability diagrams as quadrupole mass filtersB. Resonant ion ejection allows MS-MSC. All the ions that are trapped can be detectedD. All of the aboveE. B and CBarry Mather4Q: What statement(s) are true in regards to Quadrupole Ion Traps?A. They have the same stability diagrams as quadrupole mass filtersB. Resonant ion ejection allows MS-MSC. All the ions that are trapped can be detectedD. All of the aboveE. B and CAnswer:B, resonant ion injection allows MS to the n so it surely allows just MS-MS. A is wrong because the stability diagrams are different. The quadrupole's stability region is the overlapping area of two stability diagrams, in the X and Y planes. C is wrong because half the ions are ejected or more likely discharged in the opposite z direction that the detector is, so even at ideal conditions, half the ions are lost. Barry MatherWhich of the following is true about the magnetic sector analyzer?A.It separates ions by kinetic energiesB.It separates ions by their m/zC.It separates ions by their momentumD.Both a and bE.Both b and cPatrick Veres5Which of the following is true about the magnetic sector analyzer?A.It separates ions by kinetic energiesB.It separates ions by their m/zC.It separates ions by their momentumD.Both a and bE.Both b and cPatrick VeresDetectors/Mass Analyzers Question 2 A. Scan m/z, Fragment, Scan m/zB. Fragment, Fixed m/z, Scan m/zC.Scan m/z, Fragment, Fixed m/zD.Fixed m/z, Fragment, Scan m/zE. Scan m/z, Fragment , Scan m/zJessica BestIf this system was set up to conduct a daughter scan for a particular compound choose the correct operation of each quadrupole:6Detectors/Mass Analyzers Question 2 If this system was set up to conduct a daughter scan for a particular compound choose the correct operation of each quadrupole:A. Scan m/z, Fragment, Scan m/zB. Fragment, Fixed m/z, Scan m/zC.Scan m/z, Fragment, Fixed m/zD.Fixed m/z, Fragment, Scan m/zE. Scan m/z, Fragment , Scan m/zJessica BestWhich statement (are) true about ESI? I. It is an example of an atmospheric pressure ionization source II. It produces many singly charged ions. III. Its sensitivity is dependent upon total sample amount. IV. Sensitivity is higher for lipophilic compounds. (a) I, II (b) I, II, IV (c) I, IV (d) II, III(e) All of the aboveChrista Hasenkopf7Which statement (are) true about ESI? I. It is an example of an atmospheric pressure ionization source II. It produces many singly charged ions. III. Its sensitivity is dependent upon total sample amount. IV. Sensitivity is higher for lipophilic compounds. (a) I, II (b) I, II, IV (c) I, IV (d) II, III(e) All of the aboveChrista HasenkopfWhich of the following is true for low energy collision in tandem MS? 1. Fragmentation occurs through multiple collisions 2. Produces greater amino acid side chain fragmentation than high energy collisions 3. Commonly used in TOF instruments 4. Done in the presence of He or Ar 5. Collision energies are in the range of 1-20keV A. 1, 2, 4B. 2, 4C.1, 4D.2, 5E. 4, 5Jeff Butler8Which of the following is true for low energy collision in tandem MS? 1. Fragmentation occurs through multiple collisions 2. Produces greater amino acid side chain fragmentation than high energy collisions 3. Commonly used in TOF instruments 4. Done in the presence of He or Ar 5. Collision energies are in the range of 1-20keV A. 1, 2, 4B. 2, 4C.1, 4D.2, 5E. 4, 5Jeff ButlerWhich statements are true about the mass resolution of a TOF analyzer:(I) The mass resolution is proportional to the flight time. (II) In a reflectron, less energetic particles will travel with a higher velocity to "catch up" to the more energetic ones. (III) Reflectrons increase mass resolution at the expense of sensitivity. (IV) Optimization of a delayed extraction source is analyte mass-independent. (a) I, II (b) II, IV (c) III (d) I, IIIChrista Hasenkopf9Which statements are true about the mass resolution of a TOF analyzer:(I) The mass resolution is proportional to the flight time. (II) In a reflectron, less energetic particles will travel with a higher velocity to "catch up" to the more energetic ones. (III) Reflectrons increase mass resolution at the expense of sensitivity. (IV) Optimization of a delayed extraction source is analyte mass-independent. (a) I, II (b) II, IV (c) III (d) I, IIIChrista HasenkopfFor organic molecules, a broad maximum number of ions produced occurs at an electron energy of approximately 70eV, What are the reasons for this?1. At lower potentials the energy is lower than the molecular ionization energy2. There is a lower probability of electrons to interact with a molecule because they are moving too fast at higher potentials3. At higher potentials the wavelength becomes too small and molecules become ‘transparent “ to electrons4. At 70eV small changes in electron energy do not significantly affect the pattern of the spectrumA. 2,4B. 1,2,3C. 1,2,3,4D. 2,3,4E. 1,3,4Jessica Best10For organic molecules, a broad maximum number of ions produced occurs at an electron energy of approximately 70eV, What are the reasons for this?1. At lower potentials the energy is lower than the molecular ionization energy2. There is a lower probability of electrons to interact with a molecule because they are moving too fast at