30
1 Introduction to Analytical Chemistry
another via a scope hierarchy. In order to perform a quantitative analysis, one
must have some qualitative knowledge about not only the analyte but also other
species present in the sample, which might disturb the analytical process. Likewise, structural analyses rely on previously extracted qualitative and quantitative information. Distinguishing among the three variants of analysis in the
light of current approaches to Analytical Chemistry is not easy because they
share some connotations. Thus, "speciation" encompasses all three types of analysis (see second example in Box 1.4). Also, so-called "surface analysis" involves
determining the presence and relative proportion of the analyte, as well as its
spatial distribution.
A gradually abandoned but still used distinction in Analytical Chemistry is
based on the technique employed in the analytical process, i. e. on the instrument
that produces the information sought. From this standpoint, Analytical
Chemistry can be divided into Classical Analysis and Instrumental Analysis.
Classical Analysis possesses three distinct features, namely:
• it uses human senses to extract qualitative information;
• it employs the balance and the burette (for weight and volume measurements,
respectively) to derive quantitative information; and
• it uses chemical reactions in the preliminary operations of the analytical
process.
As can be seen from Fig. 1.21, Qualitative Analysis has a qualitative purpose: the
"human" identification of ions and molecules by use of (bio )chemical reactions,
whether in isolation or as parts of an established analytical separation scheme.
Its quantitative connotations materialize in Titrimetries (burette) and Gravimetries (balance). Therefore, it also uses "instruments", which reveals the artificial nature of this classification - the persistence of which is only justified on
historical grounds.
Qualitative
analysis
Quantitative
analysis
Structural
analysis
Fig.1.21. Relationship between two classifications of Analytical Chemistry
1 Introduction to Analytical Chemistry
another via a scope hierarchy. In order to perform a quantitative analysis, one
must have some qualitative knowledge about not only the analyte but also other
species present in the sample, which might disturb the analytical process. Likewise, structural analyses rely on previously extracted qualitative and quantitative information. Distinguishing among the three variants of analysis in the
light of current approaches to Analytical Chemistry is not easy because they
share some connotations. Thus, "speciation" encompasses all three types of analysis (see second example in Box 1.4). Also, so-called "surface analysis" involves
determining the presence and relative proportion of the analyte, as well as its
spatial distribution.
A gradually abandoned but still used distinction in Analytical Chemistry is
based on the technique employed in the analytical process, i. e. on the instrument
that produces the information sought. From this standpoint, Analytical
Chemistry can be divided into Classical Analysis and Instrumental Analysis.
Classical Analysis possesses three distinct features, namely:
• it uses human senses to extract qualitative information;
• it employs the balance and the burette (for weight and volume measurements,
respectively) to derive quantitative information; and
• it uses chemical reactions in the preliminary operations of the analytical
process.
As can be seen from Fig. 1.21, Qualitative Analysis has a qualitative purpose: the
"human" identification of ions and molecules by use of (bio )chemical reactions,
whether in isolation or as parts of an established analytical separation scheme.
Its quantitative connotations materialize in Titrimetries (burette) and Gravimetries (balance). Therefore, it also uses "instruments", which reveals the artificial nature of this classification - the persistence of which is only justified on
historical grounds.
Qualitative
analysis
Quantitative
analysis
Structural
analysis
Fig.1.21. Relationship between two classifications of Analytical Chemistry