This quote was written by C. N. Reilly (1925-1981), who received the 1965 Fisher Award in Analytical Chemistry. Reilly was a Professor of Chemistry at the University of North Carolina Chapel Hill and was one of the most important analytical chemists of this century.
Another view of analytical chemistry can be found in the article "Quo Vadis Analytical Chemistry?". The full reference is Valcarcel M. Anal. Bioanal. Chem. 2016, 408, 13-21.
Let's start with a simple question. What is analytical Chemistry? Analytical chemistry, like all other areas of chemistry in chemistry, is so vast and constantly changing that it is hard to find a more simple definition than the one above. This chapter will expand on this simple definition, and talk about both what analytical chemistry can be and what it isn't.
Analytical Chemistry is often described as the branch of chemistry that characterizes the composition of matter. Analytical chemistry can be described as the area of chemistry responsible for determining the composition of matter both qualitatively (Is there lead in this paint chip?) and quantitatively ("How much lead is it in this paintchip?"). This description is misleading, as we will see.
Many chemists make both qualitative and quantitative measurements every day. Some scientists believe that analytical chemistry does not exist as a separate branch of chemical chemistry. It is simply the application and understanding of chemical knowledge. You may have done many of these quantitative and qualitative analyses while studying chemistry.
For example, you might have used an acid-base method to determine the vinegar's acetic acid concentration or a qual system to determine which metal ions are present in an aqueous sample.
Analytical chemistry is not the application of chemical knowledge. This misses the unique perspective of an analytical chemist when it comes to studying chemistry. Analytical chemistry is not about performing routine analyses on routine samples--a task we appropriately refer to as chemical analysis--but rather in improving existing analytical methods, extending these analytical methods for new types of samples and developing new analytical methods that measure chemical phenomena [de Haseth J. Spectroscopy, 1990, 5(7), 11].
This is an example of the difference between chemical and analytical chemistry. An engineer mining an ore compares the cost of extracting the ore from the ground with its value. They do this by analysing a sample of ore. Analytical chemists are responsible for developing and validating quantitative analytical methods. The chemical analyst is responsible for the daily routine application of these analytical methods.