Instrumental Analysis in Chemistry
Introduction
Instrumental analysis is a branch of chemistry that uses instruments to analyze the composition of materials. It is used in a wide variety of fields, including environmental science, forensics, and pharmaceutical chemistry.
Basic Concepts
Instrumental analysis is based on the principles of spectroscopy and electrochemistry. Spectroscopy is the study of the interaction of light with matter. Electrochemistry is the study of the relationship between electricity and chemistry.
The instruments used in instrumental analysis measure the intensity of light or electricity that is absorbed, emitted, or reflected by a sample. This information can be used to determine the composition of the sample.
Equipment and Techniques
There are a wide variety of instruments used in instrumental analysis. Some of the most common include:
- Spectrophotometers
- Atomic absorption spectrometers
- Gas chromatographs
- Mass spectrometers
- Electrochemical cells
The techniques used in instrumental analysis vary depending on the instrument being used. Some of the most common techniques include:
- Spectroscopy
- Atomic absorption spectroscopy
- Gas chromatography
- Mass spectrometry
- Electrochemistry
Types of Experiments
Instrumental analysis can be used to perform a wide variety of experiments. Some of the most common experiments include:
- Qualitative analysis: Identifying the elements or compounds present in a sample.
- Quantitative analysis: Determining the concentration of a specific element or compound in a sample.
- Structural analysis: Determining the structure of a molecule.
- Kinetic analysis: Studying the rate of a chemical reaction.
- Thermodynamic analysis: Studying the energy changes that occur during a chemical reaction.
Data Analysis
The data collected from an instrumental analysis experiment must be analyzed in order to obtain meaningful information. This analysis typically involves using a computer program to process the data and generate a report.
Applications
Instrumental analysis is used in a wide variety of applications, including:
- Environmental science: Monitoring the levels of pollutants in the environment.
- Forensics: Identifying evidence in criminal cases.
- Pharmaceutical chemistry: Developing and testing new drugs.
- Food science: Ensuring the safety and quality of food products.
- Materials science: Developing new materials for a variety of applications.
Conclusion
Instrumental analysis is a powerful tool that can be used to analyze the composition of materials. It is used in a wide variety of fields, including environmental science, forensics, and pharmaceutical chemistry.
Instrumental Analysis
Instrumental analysis is a branch of analytical chemical science that uses instruments to measure physical and chemical properties of analyte in complex samples for qualitative and quantitative chemical analysis. It offers precise and accurate analysis that is also rapid and can be automated.
Main Concepts:
- Spectroscopic Analysis: Analyzes the interaction of electromagnetic radiations with matter and can be divided based on types of radiations used such as
- Atomic spectroscopy: Analyzes elements based on their unique elemental properties
- Molecular spectroscopy: Analyzes the functional groups and structures of organic and inorganic species
- Electroanalytical Analysis: Analyzes the electrochemical properties of analytes
- Conductometry: measures the ability of analyte solutions to conduct the current
- Voltammetry: scans applied potential to a solution and measures current at the working electrode
- Potentiometry: measures the potential differences between reference and working electrodes in electrochemical cells.
- Chromatographic Analysis: Separates the components of complex mixtures based on different physical properties
- Liquid chromatography: separates analytes in the liquid mobile phase
- Gas chromatography: separates analytes in the gas mobile phase
- Size-exclusion chromatography: separates analytes in the liquid mobile phase based on size
- Thermal Analysis: Analyzes changes in physical properties of a sample as a function of temperature
- Thermo-Gravimetric Analysis: measures the change in mass as function of temperature
- Differential Scanning Calorimetry: measures changes in energy as a function of temperature
Applications of Instrumental Analysis are found in various fields including environmental, clinical, pharmaceutical, and food analysis.
Spectrophotometric Determination of Iron
Materials
Iron sulfate standard solution 1,10-phenanthroline
Sodium acetate buffer Cuvettes
SpectrophotometerProcedure*
1. Prepare a series of iron sulfate standard solutions with known concentrations.
2. To each standard solution, add 1,10-phenanthroline and sodium acetate buffer.
3. Measure the absorbance of each solution at 510 nm using a spectrophotometer.
4. Plot a calibration curve of absorbance versus iron concentration.
5. Determine the concentration of iron in an unknown sample using the calibration curve.
Key Procedures
Preparation of iron sulfate standard solutions:Dissolve a known weight of iron sulfate in water. Dilute to a known volume to obtain a standard solution of known concentration. Addition of 1,10-phenanthroline and sodium acetate buffer: 1,10-phenanthroline forms a colored complex with iron ions, which is detected by the spectrophotometer. Sodium acetate buffer maintains the pH of the solution.
Measurement of absorbance:The absorbance of the solution is measured at 510 nm, which is the wavelength of maximum absorbance for the iron-1,10-phenanthroline complex. Plot of calibration curve: The calibration curve is a graph of absorbance versus iron concentration. It is used to determine the concentration of iron in an unknown sample.
Significance
This experiment demonstrates a spectrophotometric method for the determination of iron. Spectrophotometry is a widely used analytical technique in chemistry that allows for the quantitative determination of the concentration of a substance in a sample. This experiment is particularly significant because it is used to analyze iron, which is an essential element in many biological processes.