Mass Spectroscopy Principale and Its Application
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Mass spectrometry is an analytical tool useful for measuring the mass-to-charge ratio (m/z) of one or more molecules present in a sample. These measurements can often be used to calculate the exact molecular weight of the sample components as well. The principle is to ionize a sample, separate the resulting ions based on their m/z, and then detect and record the abundance of each ion. This information is then used to identify and quantify the components of the sample.
Mass Spectroscopy Principale and Its Application
- 2. INTRODUCTION : • Mass spectrometry (MS) is an analytical technique that measures the mass-to-charge ratio (m/z) of ions." • "It provides information about the composition and structure of molecules." • This technique basically studies the effect of ionizing energy on molecules. • Now a day's mass spectrometry is used in many areas including pharmaceutical, clinical, geological, biotechnology and environmental.
- 4. PRINCIPLE :• In this technique, molecules are bombarded with a beam of energetic electrons. • The molecules are ionized and broken up into many fragments, some of which are positive ions. Each kind of ion has a particular ratio of mass to charge, i.e. m/e ratio (value). • For most ions, the charge is one and thus, m/e ratio is simply the molecular mass of the ion. • The ions pass through magnetic and electric fields to reach detector where they are detected and signals are recorded to give a mass spectra.
- 6. INSTRUMENTATION : • A. Sample Inlet • Sample stored in large reservoir from which molecules reaches ionization chamber at low pressure in steady stream by a pinhole called "Molecular leak". • B. Ionization • Atoms are ionized by knocking one or more electrons off to give positive ions by bombardment with a stream of electrons. Most of the positive ions formed will carry charge of +1. • lonization can be achieved by: • Electron ionization (EI-MS) • Chemical ionization (CI-MS) • Desorption Technique (FAB)
- 7. • C. Acceleration • ions are accelerated so that they all have same kinetic energy. • Positive ions pass through 3 slits with voltage in decreasing order. • Middle slit carries intermediate and finals at zero volts. • D. Deflection • ions are deflected by a magnetic field due to difference in their masses. • The lighter the mass, more they are deflected. • It also depends upon the no. of +ve charge an ion is carrying; the more +ve charge, more it will be deflected.
- 8. • E. Detection • The beam of ions passing through the mass analyzer is detected by detector on the basis of m/e ratio. • When an ion hit the metal box, charge is neutralized by an electron jumping from metal on to the ion.
- 9. • APPLICATION : • Environmental monitoring and analysis (soil, water and air pollutants, water quality, etc.). • Chemical and Petrochemical industry - Quality control. • Identify structures of biomolecules, such as carbohydrates, nucleic acids • Sequence biopolymers such as proteins and oligosaccharides • Determination of molecular mass of peptides, proteins, and oligonucleotides. • Monitoring gases in patients breath during surgery. • Identification of drugs abuse and metabolites of drugs of abuse in blood, urine, and saliva.
- 10. • Advantages: • High Sensitivity: • Mass spectrometry can detect and quantify even trace amounts of substances, making it ideal for analyzing samples with very low concentrations. • High Specificity: • The mass-to-charge ratio (m/z) provides a unique fingerprint for each molecule, allowing for accurate identification and differentiation of compounds. • Versatility: • Mass spectrometry can be used to analyze a wide range of substances, including small molecules, proteins, polymers, and even complex mixtures. • Structural Information: • Fragmentation patterns in mass spectra can provide valuable information about the structure and chemical properties of molecules. • Isotopic Information: • Mass spectrometry can determine the isotopic composition of a sample, which is useful in various applications, such as carbon dating and tracing metabolic pathways. • Coupling with other Techniques: • Mass spectrometry is often coupled with separation techniques like Gas chromatography (GC-MS) and Liquid chromatography (LC-MS) greatly enhancing the ability to analyze complex mixtures. • Disadvantages: • Cost: • Sample Preparation: • Some samples require extensive preparation before they can be analyzed by mass spectrometry, which can be time-consuming and labor-intensive. • Vacuum requirements: • Mass spectrometers operate under high vacuum conditions, which adds to the complexity of the instrument.
- 13. • https://images.app.goo.gl/9ucH • https://images.app.goo.gl/7m1u • https://youtu.be/w3LS22E10Zc?si=z3aksI9OHQSGw8DG Reference :