cgifbribcgfbi/Meta-Llama-3.1-8B-Instruct-abliterated-chem-textbook
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| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/00%3A_Front_Matter/02%3A_InfoPage | This text is disseminated via the Open Education Resource (OER) LibreTexts Project and like the hundreds of other texts available within this powerful platform, it is freely available for reading, printing and "consuming." Most, but not all, pages in the library have licenses that may allow individuals to make changes... | 1 |
2.1: Direct Vapor Inlet
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/02%3A_SAMPLE_INTRODUCTION/2.01%3A_Direct_Vapor_Inlet | Direct Vapor Inlet. The simplest sample introduction method is a direct vapor inlet. The gas phase analyte is introduced directly into the source region of the mass spectrometer through a needle valve. Pump out lines are usually included to remove air from the sample. This inlet works well for gases, liquids, or solids... | 5 |
2.2: Gas Chromatography
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/02%3A_SAMPLE_INTRODUCTION/2.02%3A_Gas_Chromatography | Gas chromatography is probably the most common technique for introducing samples into a mass spectrometer. Complex mixtures are routinely separated by gas chromatography and mass spectrometry is used to identify and quantitate the individual components. Several different interface designs are used to connect these two ... | 6 |
2.3: Liquid Chromatography
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/02%3A_SAMPLE_INTRODUCTION/2.03%3A_Liquid_Chromatography | Liquid Chromatography. Liquid chromatography inlets are used to introduce thermally labile compounds not easily separated by gas chromatography. These inlets have undergone considerable development and LC/MS is now fairly routine. Because these inlets are used for temperature sensitive compounds, the sample is ionized ... | 7 |
2.4: Direct Insertion Probe
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/02%3A_SAMPLE_INTRODUCTION/2.04%3A_Direct_Insertion_Probe | Direct Insertion Probe. The Direct Insertion Probe (DIP) is widely used to introduce low vapor pressure liquids and solids into the mass spectrometer. The sample is loaded into a short capillary tube at the end of a heated sleeve. This sleeve is then inserted through a vacuum lock so the sample is inside the source reg... | 8 |
2.5: Direct Ionization of Sample
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/02%3A_SAMPLE_INTRODUCTION/2.05%3A_Direct_Ionization_of_Sample | Direct Ionization of Sample. Unfortunately, some compounds either decompose when heated or have no significant vapor pressure. These samples may be introduced to the mass spectrometer by direct ionization from the condensed phase. These direct ionization techniques include electrospray, matrix assisted laser desorption... | 9 |
3.1: Electron Ionization
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.01%3A_Electron_Ionization | Electron Ionization (EI) is the most common ionization technique used for mass spectrometry.* EI works well for many gas phase molecules, but it does have some limitations. Although the mass spectra are very reproducible and are widely used for spectral libraries, EI causes extensive fragmentation so that the molecular... | 12 |
3.2: Chemical Ionization
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.02%3A_Chemical_Ionization | Chemical Ionization (CI) is a soft ionization technique that produces ions with little excess energy. As a result, less fragmentation is observed in the mass spectrum. Since this increases the abundance of the molecular ion, the technique is complimentary to 70 eV EI. CI is often used to verify the molecular mass of an... | 13 |
3.3: Atmospheric Pressure Ionization and Electrospray Ionization
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.03%3A_Atmospheric_Pressure_Ionization_and_Electrospray_Ionization | Atmospheric Pressure Ionization (API) sources ionize the sample at atmospheric pressure and then transfer the ions into the mass spectrometer. These techniques are used to ionize thermally labile samples such as peptides, proteins and polymers directly from the condensed phase. The sample is dissolved in an appropriate... | 14 |
3.4: Matrix Assisted Laser Desorption/Ionization
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.04%3A_Matrix_Assisted_Laser_Desorption_Ionization | Matrix Assisted Laser Desorption/Ionization (MALDI) is used to analyze extremely large molecules. This technique directly ionizes and vaporizes the analyte from the condensed phase. MALDI is often used for the analysis of synthetic and natural polymers, proteins, and peptides. Analysis of compounds with molecular weigh... | 15 |
3.5: Fast Atom Bombardment and Secondary Ion Mass Spectrometry
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.05%3A_Fast_Atom_Bombardment_and_Secondary_Ion_Mass_Spectrometry | Fast Atom Bombardment (FAB) and Secondary Ion Mass Spectrometry (SIMS) both use high energy atoms to sputter and ionize the sample in a single step. In these techniques, a beam of rare gas neutrals (FAB) or ions (SIMS) is focused on the liquid or solid sample. The impact of this high energy beam causes the analyte mole... | 16 |
3.6: Inductively Coupled Plasma
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.06%3A_Inductively_Coupled_Plasma | In addition to use for atomic emission spectroscopy, Inductively Coupled Plasma (ICP) is also used as an ionization method for elemental analysis. A liquid or slurry sample is introduced into an inductively coupled plasma torch and the ions produced are extracted and analyzed by mass spectrometry. These instruments a... | 17 |
3.7: Self-Test #1
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/03%3A_IONIZATION_TECHNIQUES/3.07%3A_Self-Test_1 | What ionization technique would be appropriate for analyzing the following compounds:1) Gasoline fractions. Since these are very volatile, EI would be very easy to use and would provide abundant fragment information. CI may help to identify the molecular ions.2) Pesticide residue. These are usually volatile enough to u... | 18 |
4.1: Quadrupole
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.01%3A_Quadrupole | The quadrupole mass spectrometer is the most common mass analyzer. Its compact size, fast scan rate, high transmission efficiency,* and modest vacuum requirements are ideal for small inexpensive instruments. Most quadrupole instruments are limited to unit m/z resolution** and have a mass range of 1000 m/z . Many bench... | 19 |
4.2: Magnetic Sector
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.02%3A_Magnetic_Sector | Magnetic Sector. The first mass spectrometer, built by J.J. Thompson in 1897 , used a magnet to measure the m/z value of an electron. Magnetic sector instruments have evolved from this same concept. Sector instruments have higher resolution and greater mass range than quadrupole instruments, but they require larger vac... | 20 |
4.3: Electric Sector/Double Focusing Mass Spectrometers
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.03%3A_Electric_Sector_Double_Focusing_Mass_Spectrometers | Electric Sector/Double Focusing Mass Spectrometers. An electric sector consists of two concentric curved plates. A voltage is applied across these plates to bend the ion beam as it travels through the analyzer. The voltage is set so that the beam follows the curve of the analyzer. The radius of the ion trajectory (r) d... | 21 |
4.4: Time-of-Flight
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.04%3A_Time-of-Flight | Time-of-Flight. The time-of-flight (TOF) mass analyzer separates ions in time as they travel down a flight tube ). This is a very simple mass spectrometer that uses fixed voltages and does not require a magnetic field. The greatest drawback is that TOF instruments have poor mass resolution, usually less than 500 . Thes... | 22 |
4.5: Quadrupole Ion Trap
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.05%3A_Quadrupole_Ion_Trap | The Quadrupole ion storage trap mass spectrometer (QUISTOR) is a recently developed mass analyzer with some special capabilities. Several commercial instruments are available and this analyzer is becoming more popular. QUISTORs are very sensitive, relatively inexpensive, and scan fast enough for GC/MS exp eriments. The... | 23 |
4.6: Ion Cyclotron Resonance
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.06%3A_Ion_Cyclotron_Resonance | Ion Cyclotron Resonance. The Ion Cy clotron Resonance (ICR) mass spectrometer uses a superconducting magnet to trap ions in a small sample cell. This type of mass analyzer has extremely high mass resolution (ca. \(10^{9}\) ) and is also useful for tandem mass spectrometry experiments. These instruments are very expensi... | 24 |
4.7: Self-Test #2
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/04%3A_MASS_ANALYZERS/4.07%3A_Self-Test_2 | Self-Test #2: Which mass analyzer is appropriate for the following analysis:Self-Test #2: Which mass analyzer would be appropriate for the following analysis:1) Routine analysis of drug testing samples. A quadrupole mass analyzer would provide the necessary mass range and resolution. It is also fast enough for use with... | 25 |
5.1: Vacuum System
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/05%3A_MASS_SPECTROMETER_SYSTEMS/5.01%3A_Vacuum_System | All mass spectrometers operate at very low pressure (high vacuum). This reduces the chance of ions colliding with other molecules in the mass analyzer. Any collision can cause the ions to react, neutralize, scatter, or fragment. All these processes will interfere with the mass spectrum. To minimize collisions, experime... | 26 |
5.2: Source Region Control
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/05%3A_MASS_SPECTROMETER_SYSTEMS/5.02%3A_Source_Region_Control | The mass spectrometer system will also include controls for the source region. These controls will vary depending upon the ionization technique being used for analysis. For GC/MS and LC/MS systems this software will also control the chromatography system. In general, this requires setting parameters that control the t... | 27 |
5.3: Mass Analyzer Control
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/05%3A_MASS_SPECTROMETER_SYSTEMS/5.03%3A_Mass_Analyzer_Control | Control of the mass analyzer requires adjustment of voltages and currents described for the operation of the analyzer and control over voltages on the ion lenses that focus and direct the ions to the detector. The user will need to set the mass range for the analysis. The mass range is limited by the design of the in... | 28 |
5.4: Detector Control
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/05%3A_MASS_SPECTROMETER_SYSTEMS/5.04%3A_Detector_Control | Detection of ions is based up on their charge or momentum. For large signals a faraday cup is used to collect ions and measure the current. Older instruments used photographic plates to measure the ion abundance at each mass to charge ratio. Most detectors currently used amplify the ion signal using a collector similar... | 29 |
5.5: Data System
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/05%3A_MASS_SPECTROMETER_SYSTEMS/5.05%3A_Data_System | The final component of a mass spectrometer is the data system. This part of the instrument has undergone revolutionary changes. It has evolved from photographic plates and strip chart recorders to data systems that control the instrument, acquire hundreds of spectra in a minute and search tens of thousands of reference... | 30 |
6.1: Molecular Ion
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/06%3A_INTERPRETATION/6.01%3A_Molecular_Ion | The molecular ion provides the molecular mass of the analyte and is the first clue used to interpret a mass spectrum. The mass to charge ratio of the molecular ion is based up on the mass of the most abundant isotope for each element in the molecule. This is not the relative atomic mass from the periodic table. Since m... | 31 |
6.2: Fragmentation
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/06%3A_INTERPRETATION/6.02%3A_Fragmentation | Although the molecular ion is useful for identification, it does not provide any structural information about an unknown. The structural information is obtained from the fragmentation patterns of the mass spectrum. Identifying an unknown without analyzing the fragmentation patterns is like putting together a jigsaw puz... | 32 |
6.3: Rearangement
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/06%3A_INTERPRETATION/6.03%3A_Rearangement | The mass spectrum of heptane is shown in . This mass spectrum is consistent with the fragmentation patterns discussed in the previous section. The molecular ion, C7H16•+ is observed at 100 m/z and a series of cleavage peaks are observed for loss of CH3• (M - 15), C2H5• (M - 29), and C3H7• (M - 43). These peaks are... | 33 |
6.4: Isotope Abundance
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/06%3A_INTERPRETATION/6.04%3A_Isotope_Abundance | The existence of isotopes was first observed by Aston using a mass spectrometer to study neon ions. When interpreting mass spectra it is important to remember that the relative atomic mass or atomic weight of an element is a weighted average of the naturally occurring isotopes. Mass spectrometers separate these isotope... | 34 |
6.5: Amine Fragmentation
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/06%3A_INTERPRETATION/6.05%3A_Amine_Fragmentation | Functional groups can have a significant effect the fragmentation patterns observed in mass spectrometry and textbooks on mass spectrometry cover a large range of common fragmentation patters for different functional groups. For a detailed discussion of this, interested readers are encouraged to look at any of the fol... | 35 |
6.6: Exact Mass
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/An_Introduction_to_Mass_Spectrometry_(Van_Bramer)/06%3A_INTERPRETATION/6.06%3A_Exact_Mass | Exact Mass. In most mass spectrometry experiments the nominal mass is used and the mass to charge ratio of an ion is rounded to the nearest whole number. High resolution instruments, including double focusing and FT-ICR mass spectrometers, are capable of determining the "exact mass" of an ion. This is useful for interp... | 36 |
InfoPage
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/00%3A_Front_Matter/02%3A_InfoPage | This text is disseminated via the Open Education Resource (OER) LibreTexts Project and like the hundreds of other texts available within this powerful platform, it is freely available for reading, printing and "consuming." Most, but not all, pages in the library have licenses that may allow individuals to make changes... | 38 |
1.1: What is Analytical Chemistry
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/01%3A_Introduction_to_Analytical_Chemistry/1.01%3A_What_is_Analytical_Chemistry | This quote is attributed to C. N. Reilly on receipt of the 1965 Fisher Award in Analytical Chemistry. Reilly, who was a professor of chemistry at the University of North Carolina at Chapel Hill, was one of the most influential analytical chemists of the last half of the twentieth century.For another view of what consti... | 41 |
1.2: The Analytical Perspective
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/01%3A_Introduction_to_Analytical_Chemistry/1.02%3A_The_Analytical_Perspective | Having noted that each area of chemistry brings a unique perspective to the study of chemistry, let’s ask a second deceptively simple question: What is the analytical perspective? Many analytical chemists describe this perspective as an analytical approach to solving problems.For different viewpoints on the analytical ... | 42 |
1.3: Common Analytical Problems
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/01%3A_Introduction_to_Analytical_Chemistry/1.03%3A_Common_Analytical_Problems | Many problems in analytical chemistry begin with the need to identify what is present in a sample. This is the scope of a qualitative analysis, examples of which include identifying the products of a chemical reaction, screening an athlete’s urine for a performance-enhancing drug, or determining the spatial distributio... | 43 |
1.5: Additional Resources
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/01%3A_Introduction_to_Analytical_Chemistry/1.05%3A_Additional_Resources | The role of analytical chemistry within the broader discipline of chemistry has been discussed by many prominent analytical chemists; several notable examples are listed here.For additional discussion of clinical assays based on paper-based microfluidic devices, see the following papers.This textbook provides one intro... | 45 |
1.6: Chapter Summary and Key Terms
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/01%3A_Introduction_to_Analytical_Chemistry/1.06%3A_Chapter_Summary_and_Key_Terms | Analytical chemists work to improve the ability of chemists and other scientists to make meaningful measurements. The need to work with smaller samples, with more complex materials, with processes occurring on shorter time scales, and with species present at lower concentrations challenges analytical chemists to improv... | 46 |
10.1: Overview of Spectroscopy
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/10%3A_Spectroscopic_Methods/10.01%3A_Overview_of_Spectroscopy | The focus of this chapter is on the interaction of ultraviolet, visible, and infrared radiation with matter. Because these techniques use optical materials to disperse and focus the radiation, they often are identified as optical spectroscopies. For convenience we will use the simpler term spectroscopy in place of opti... | 47 |
10.2: Spectroscopy Based on Absorption
| https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/10%3A_Spectroscopic_Methods/10.02%3A_Spectroscopy_Based_on_Absorption | In absorption spectroscopy a beam of electromagnetic radiation passes through a sample. Much of the radiation passes through the sample without a loss in intensity. At selected wavelengths, however, the radiation’s intensity is attenuated. This process of attenuation is called absorption.There are two general requireme... | 48 |
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