Instrumental Analysis Techniques and Physical Properties

Analysis and Instrumentation

Physical Properties:

• Hardness
• Color
• Shape
• Smell
• Ductility
• Density
• Flavor
• Malleability
• Volatility
• Viscosity
• Conductivity
• Weight
• Volume
• Brightness
• Porosity
• Toughness
• Boiling Point (Punto de ebullición)
• Melting Point (Punto de fusión)

Chemical Properties:

Chemical reactions.

Composition:

CaCO3 100%

Determining the Composition of Liquids, Gases, and Solutions: Instrumental Applications

Objectives:

• To know the fundamentals and applications of instrumental techniques in environmental engineering.
• Understand the general problem of analysis.
• Purchase criteria for a particular control method.
• Analysis, sampling, preservation, and preparation of samples.
• Distinguish the key parts and functions of each instrumental technique.
• Interpret information obtained from these techniques.

Concept of Instrumental Analysis:

The analysis carried out using chemical equipment that measures some property of compounds. Example: intensity of radiation absorbed or emitted, number of ions, etc.

Classification of Instrumental Methods of Analysis

Optical Methods:

• Spectrophotometry (Visible)
• UV-Absorption Spectroscopy
• IR Spectroscopy
• Atomic Spectroscopy
• X-ray Spectroscopy

Electrochemical Methods:

• Potentiometry
• Polarography
• Electrogravimetry
• Coulometry

Separation Methods:

• Chromatographic Methods

Thermal Methods:

• Differential Thermal Analysis (DTA)
• Thermogravimetry
• Scanning Calorimetry (DSC)

Other Methods:

• Nuclear Magnetic Resonance (NMR)
• Mass Spectrometry (MS)

Detailed Method Descriptions

Optical Methods:

Optical methods all involve an interaction between matter and electromagnetic radiation. They are based on classical optical phenomena such as absorption, emission, diffraction, and dispersion, covering the range of the electromagnetic spectrum from X-rays to microwaves.

Electrochemical Methods:

Based on the electrochemical properties of solutions.

Separation Methods:

Chromatographic Methods: Constitute one of the major groups of instrumental methods due to their contribution to studying complex mixtures.

Thermal Methods:

Phase transitions studied by observing the heat absorbed or released. Weight is recorded while heating in an oven. Reactions proceed during heating, observed by measurement.

General Analytical Process:

Identification Problem --- Choice of Instrumental Technique --- Sampling --- Sample Preparation --- Instrumental Measurement --- Evaluation of Data --- Final Report and Conclusions

Analytical Process Steps:

Approach the Problem:

The concentration range being worked on can limit the number of possible methods. A lower concentration requires a more sensitive method employed.

Required Degree of Accuracy:

Consider other components present in the sample determination. To choose a method for one or more species, it is necessary to know what other compounds accompany them, as interference is possible. Identify certain physical and chemical properties of the sample. Determine how many samples need to be analyzed.