PHD
  1. Inorganic chemistry  1.1. Coordination chemistry  1.1.1. Ligand field theory  1.1.2. Crystal field theory  1.1.3. Molecular Orbital Theory for Coordination Compounds  1.1.4. Stability of Coordination Compounds  1.1.5. Electronic spectra of coordination compounds  1.1.6. Isomerism in Coordination Compounds  1.1.7. Kinetics and mechanism of coordination reactions  1.2. Organometallic Chemistry  1.2.1. Metal Carbonyls  1.2.2. Metal alkyl and aryl  1.2.3. Fischer and Schrock carbonaceans  1.2.4. Oxidative Addition and Reductive Elimination  1.2.5. Metal Hydrides  1.2.6. Catalysis by organometallic compounds  1.2.7. Metallocenes and Sandwich Complexes  1.2.8. CH activation  1.3. Solid state chemistry  1.3.1. Crystal structures and lattices  1.3.2. Band theory and electrical properties  1.3.3. Defects in the crystal  1.3.4. Synthesis of solid state materials  1.3.5. Magnetic and optical properties of solids  1.3.6. Superconductivity  1.3.7. Solid state ionics  1.4. Bio-inorganic chemistry  1.4.1. Metalloproteins and enzymes  1.4.2. Metal ion transport and storage  1.4.3. The role of metals in medicine  1.4.4. Bioinspired catalysis  1.4.5. Metal–DNA interactions  1.4.6. Metal Complexes in Medical Science  1.5. Lanthanides and Actinides  1.5.1. Electronic configuration and oxidation states in lanthanides and actinides  1.5.2. Spectral and Magnetic Properties in Lanthanides and Actinides  1.5.3. Separation and Extraction of Lanthanides and Actinides  1.5.4. Coordination chemistry of f-block elements  1.6. Main Group Chemistry  1.6.1. Chemistry of boron compounds  1.6.2. Chemistry of Silicon and Germanium Compounds  1.6.3. Chemistry of Phosphorus and Sulfur Compounds  1.6.4. Organosilicon chemistry  1.6.5. Noble Gas Chemistry
  2. Organic chemistry  2.1. Reaction mechanism  2.1.1. Nucleophilic substitution reactions  2.1.2. Electrophilic addition and substitution reactions  2.1.3. Elimination reactions  2.1.4. Rearrangement reactions  2.1.5. Radical reactions  2.1.6. Pericyclic Reactions  2.1.7. Photochemical reactions  2.2. Stereoscopic  2.2.1. Chirality and optical activity  2.2.2. Structural analysis  2.2.3. Stereoelectronic effects  2.2.4. Asymmetric synthesis  2.2.5. Dynamic Stereochemistry  2.3. Organometallic Chemistry in Organic Synthesis  2.3.1. Organolithium and organomagnesium reagents  2.3.2. Transition metal catalyzed coupling reactions  2.3.3. Palladium-catalyzed reactions  2.3.4. Olefin Metathesis  2.3.5. Gold and silver catalysis  2.4. Natural products chemistry  2.4.1. Alkaloids and terpenoids  2.4.2. Steroids and Flavonoids  2.4.3. Total synthesis of natural products  2.4.4. Biosynthesis of natural products  2.5. Supramolecular Chemistry  2.5.1. Host-Guest Chemistry  2.5.2. Self-assembly and molecular recognition  2.5.3. Supramolecular Catalysis  2.5.4. Molecular Machines
  3. Physical Chemistry  3.1. Thermodynamics  3.1.1. Laws of Thermodynamics  3.1.2. Chemical Potential and Equilibrium  3.1.3. Statistical thermodynamics  3.1.4. Non-equilibrium thermodynamics  3.2. Quantum Chemistry  3.2.1. Schrödinger equation and its applications  3.2.2. Molecular orbital theory  3.2.3. Density functional theory  3.2.4. Post-Hartree–Fock methods  3.3. Chemical kinetics  3.3.1. Reaction rate theory  3.3.2. Mechanism and rate laws  3.3.3. Catalysis and enzyme kinetics  3.3.4. Reaction dynamics  3.4. Spectroscopy and molecular structure  3.4.1. Infrared Spectroscopy  3.4.2. UV-visible spectroscopy  3.4.3. Nuclear Magnetic Resonance Spectroscopy  3.4.4. Mass Spectrometry  3.4.5. Raman Spectroscopy  3.5. Surface and Colloid Chemistry  3.5.1. Absorption and Catalysis  3.5.2. Surfactants and micelles  3.5.3. Colloidal Stability  3.5.4. Nanomaterials and Interfaces
  4. Analytical chemistry  4.1. Chromatography  4.1.1. Gas Chromatography  4.1.2. High Performance Liquid Chromatography  4.1.3. Thin Layer Chromatography  4.1.4. Ion Chromatography  4.2. Electroanalytical techniques  4.2.1. Voltammetry and Polarography  4.2.2. Conductometry and potentiometry  4.2.3. Colometry  4.3. Spectroscopic Methods  4.3.1. Atomic absorption spectroscopy  4.3.2. Fluorescence Spectroscopy  4.3.3. X-ray diffraction  4.3.4. Electron paramagnetic resonance spectroscopy  4.4. Chemometrics  4.4.1. Data processing and statistical methods  4.4.2. Multidisciplinary analysis  4.4.3. Machine Learning in Analytical Chemistry
  5. Theoretical and Computational Chemistry  5.1. Molecular dynamics simulation  5.2. Quantum chemistry methods  5.3. Computational drug design  5.4. Machine Learning in Chemistry  5.5. Ab initio molecular dynamics
  6. Biophysics and Medicinal Chemistry  6.1. Drug discovery and design  6.2. Enzyme kinetics and inhibition  6.3. Chemical biology approach  6.4. Protein-ligand interactions  6.5. Bioorthogonal chemistry
  7. Materials chemistry  7.1. Polymer chemistry  7.1.1. Polymerization mechanism  7.1.2. Functional Polymers  7.1.3. Biodegradable Polymer  7.1.4. Conducting and semiconducting polymers  7.2. Nano Chemistry  7.2.1. Nanoparticles and nanostructures  7.2.2. Carbon-based nanomaterials  7.2.3. Quantum dots  7.3. Energy and Environmental Chemistry  7.3.1. Battery and Fuel Cell Chemistry  7.3.2. Green chemistry and sustainable materials  7.3.3. Photocatalysis

PHD ↓


Analytical chemistry


Analytical chemistry is a branch of chemistry that deals with the study of the composition of substances. It involves the analysis of substances to determine their structure and the quantification of the components that make up the substances. Analytical chemistry is important to many scientific fields, including biology, physics, and environmental science. In this document, we will explore analytical chemistry in detail, covering its fundamental concepts, methods, and applications.

Introduction to analytical chemistry

Analytical chemistry focuses on understanding the chemical composition of substances. This can involve anything from determining the amount of sodium in a seawater sample to figuring out the structure of a newly synthesized compound in the laboratory to ensuring the purity of pharmaceutical ingredients. The core of analytical chemistry is the development and application of techniques for measuring the chemical composition of substances.

There are two main types of analysis in analytical chemistry: qualitative analysis, which identifies what is present in a sample, and quantitative analysis, which determines how much of each component is present. Both types of analysis rely on a number of techniques and methods, from simple methods such as measuring weight or volume to more complex methods involving spectroscopy or chromatography.

Qualitative analysis

Qualitative analysis refers to the identification of the components of a sample. In other words, it answers the question: What is in this sample? For example, if you have a sample of an unknown compound, qualitative analysis will help you determine the elements or ions present in that compound.

Students and professionals use several classic methods in qualitative analysis. For visualization, consider the following simple reactions:

Ag+ + Cl- → AgCl (s)
Fe3+ + SCN- → [Fe(SCN)]2+

In the first reaction, silver ions react with chloride ions to form a white precipitate of silver chloride. This precipitate indicates the presence of chloride ions in the solution. Similarly, in the second reaction, iron (III) ions react with thiocyanate ions to form a red complex, indicating the presence of iron ions.

Quantitative analysis

Quantitative analysis is about measuring the amount of components in a sample. This type of analysis helps answer the question: How much of each substance is there? Techniques used in quantitative analysis can determine the concentration of a given element or compound in a sample.

A common method of quantitative analysis is titration, which involves adding reactants to a sample until the reaction is complete. The point of completion is often indicated by a color change (when an indicator is used). For example, to determine the concentration of hydrochloric acid in a solution, you can titrate with a sodium hydroxide solution of known concentration:

NaOH + HCl → NaCl + H2O

When the end point is reached, you can use the amount of sodium hydroxide added to calculate the concentration of hydrochloric acid in the original sample.

Analytical techniques and instrumentation

There are many instruments and techniques used in analytical chemistry, each suitable for different types of analysis. Some common methods are:

Spectroscopy

Spectroscopy involves the study of how light interacts with matter. By analyzing this interaction, scientists can make inferences about the structure, bonding, and concentration of chemical substances. Several types of spectroscopy are commonly used:

  • UV/Vis Spectroscopy: This method measures the absorption of UV or visible light by a sample. It is useful for determining the concentration of absorbing species such as organic compounds.
  • Infrared (IR) spectroscopy: This technique is used to identify functional groups in a compound. Each type of bond vibrates at different frequencies, which are identified as distinct peaks in the IR spectrum.
  • Nuclear magnetic resonance (NMR) spectroscopy: NMR provides detailed information about the structure of organic compounds by studying the magnetic properties of atomic nuclei.

For example, if a chemist needs to understand the functional groups in an organic molecule, they can use IR spectroscopy and look for peaks corresponding to different bond vibrations, such as CH, OH, or NH.

Chromatography

Chromatography is a technique used to separate components of a mixture based on their differential interactions with the stationary phase and the mobile phase. Some common types of chromatography include:

  • Gas Chromatography (GC): It is used to separate and analyze compounds that can vaporize without decomposing.
  • High performance liquid chromatography (HPLC): Used for separation of components in the liquid phase.
  • Thin Layer Chromatography (TLC): A simple and quick method used to check the purity or progress of a reaction.

Consider a mixture of compounds that can be detected using HPLC. As the individual components pass through a column, they are separated and detected, allowing their concentrations to be determined.

Mass spectrometry

Mass spectrometry is a powerful tool for identifying chemical substances based on the mass-to-charge ratio of ions. This technique provides information about the molecular weight and structure of a compound, making it invaluable for identifying unknown substances.

Considering a real-world example, pharmaceutical companies often use mass spectrometry in drug development to ensure the correct molecular structure is obtained in synthesis.

Applications of analytical chemistry

Analytical chemistry has countless applications in a variety of fields, including:

Environmental testing

Analytical chemistry plays a vital role in monitoring and maintaining the health of our environment. Techniques are used to detect pollutants in air, water, and soil, helping scientists assess the level of contamination and devise appropriate response strategies. For example, ICP-MS (inductively coupled plasma mass spectrometry) can be used to measure trace metals in water samples, ensuring they are within safe limits for human consumption.

Pharmaceutical analysis

In the pharmaceutical industry, analytical chemistry ensures the safety and efficacy of drugs. Techniques such as HPLC are used to quantify active ingredients and check for impurities, while NMR can confirm structural configurations. This rigorous analysis is crucial in drug development and quality control.

Food & beverage testing

Analytical chemistry techniques ensure the quality and safety of food products. Nutrient content, preservative levels, and contamination are routinely analyzed using chromatography and spectrometry, helping to maintain food quality and safety standards.

Visual example

Imagine that you have a solution and you need to determine the concentration of blue dye in it. Use UV/Vis spectroscopy for this quantitative analysis:

sample solution containing blue colour

A light source is shone through the sample, and the detector measures how much light of different wavelengths the sample absorbs. The greater the absorption at a particular wavelength, the greater the concentration of the dye.

Conclusion

Analytical chemistry is an essential field that connects many scientific disciplines. By focusing on methods and techniques to determine both the qualitative and quantitative aspects of chemical substances, analytical chemistry enables innovation and safety in many vital industries. From identifying pollutants in our environment to ensuring the efficacy of pharmaceuticals, the applications of analytical chemistry are as vast as they are important.


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