Among the different branches of chemistry, analytical chemistry is a science that deals with means of measuring the chemical composition of natural and artificial materials. The techniques of this science are used to separate and identify the substances which may be present in a material and determine the exact amounts (quantify) of the identified substances via various modern techniques such as spectroscopy, chromatography, etc. and/or also through classical means. For the study purpose, species can be analyzed in two ways - qualitative analysis and quantitative analysis in analytical chemistry:
1) Qualitative: - This provides information about the identity of an atomic, molecular, or bimolecular species, which means it identifies analytes.
2) Quantitative: - This provides numerical information as to the relative amounts of species,
which means numerical amount or concentration can be known by doing qualitative analysis.
Analytical chemistry consists of broadly classical and instrumental methods of analysis.
In the classical qualitative approach, we use separation techniques such as precipitation, extraction, and distillation. In this case, identification may be based on difference in color, odor, melting point, boiling point, radioactivity, or reactivity. Thus, the individual judgment is very important as seen by the naked eye as well.
In classical quantitative approach, we make an analysis by measuring mass or volume changes in order to quantify amount.
Instrumental methods may be used to separate samples using chromatography, electrophorus, or field flow fractionation. In the instrumental method, both qualitative and quantitative analysis can be performed with the same instrument which can separate, identify and even quantify an analyte or species under examination.
The role of analytical chemistry and chemists: According to Friedrich Wilhelm Ostwald(1894): “Analytical chemistry, or the art of recognizing different substances and determining their constituents, takes a prominent position among the applications of science, since the questions which it enables us to answer arise wherever chemical processes are employed for scientific or chemical purposes.” (http://www.csudh.edu/oliver/che230/textbook/ch01.htm).
Analytical chemists work to improve the reliability of existing techniques. They adopt proven methodologies to new kinds of materials or to answer new questions about their composition. They work to discover completely new principles of measurements & are at the forefront of the utilization of major discoveries for practical purposes.
Applications: This science is applied in various fields; the following are given as examples:
Clinical analytical chemistry: In a clinic this science is used to make analysis of blood or urine,
Quality control: As an example, this science can be used for comparison of DNA codes.
Environmental Analytical chemistry: This science is the applied science in environmental engineering or science in such things as analysis of the heavy metals in soil.
This science is also widely adopted in the medicine industry and environmental food and agriculture forensics.
Techniques in chemical analysis: For the analysis of species there are various techniques. Some examples are separation techniques such as are utilized in chromatography, spectroscopic techniques, mass spectrometry, electrochemical techniques, microscopic, and surface techniques.
In an undergraduate course in analytical chemistry, the basic subject is covered and has limited study. The information provided here is for a specialized subject in a master’s program which is studied all over the world.
Students can get additional help in the subject matter from the following online open course site http://nptel.ac.in/courses/104104066/ as well as wikipedia.org and MIT open courseware site.