Analytical Properties
Objectives
• To define analytical properties in a global. consistent manner. with emphasis
on their theoretical and practical significance.
• To assign analytical properties unequivocally to specific aspects of Analytica l
Chemistry.
• To establish foundation, complementary and contradictory relationships
among analytical properties.
• To relate analytical properties to different facets of analytical quality.
Table of Contents
2.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.2
The Chemical Metrological Hierarchy: Uncertainty and Trueness . . . .. .. . .. 41
2.3
Errors in Analytical Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 45
2.4
Capital Analytical Properties . .. . . . . .. . . . . . . .. . . .. ... .. . .. 52
2.4.1 Accuracy . . . .. .. . . . .. .. .. . . . .... . ... . . . . .. . . . 53
2.4.2 Representativeness . . . . ... . . . . . . .. . .. . . . . .. . . ... . 54
2.5
Basic Analytical Properties .. .. ............. . .. . . . .. . .. . . 56
2.5.1 Precision. . ..... .. . . . .. . . .. .. . . . . . .. .. . . . . .. . 57
2.5.2 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 65
2.5.3 Selectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
2.6
Accessory Analytical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
2.6.1 Expeditiousness.. . .......... . .. . . . ..... . ... . ... 73
2.6.2 Cost-effectiveness....... .. . . . .. . . .. ... . . . . .... . . 73
2.6.3 Personnel-related Factors . . . . . . . . . . . . . . . . . . . . . . . . . .. 75
2.7
Relationships among Analytical Properties . ... ... . .. . . . . . . . .. . . 75
2.7.1 Hierarchical Relationships . . . . . . . . . . . . . . . . . . . . . . . . . .. 76
2.7.2 Foundation Relationships . . . . . . . . . . . . . . . . . . . . . . . . . .. 77
2.7.3 Contradictory Relationships ... . ..... . . . ... . ......... 77
2.7.4 Complementary Relationships . ... . . . .. . . . . .. .. . . ... . . 81
2.8
Other Analytical Properties . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Questions . .. . . . . .............. . ..... . .. . .. . ..... . ... . . . 87
Seminars: Numerical Problems .. .. .. ... . . .. . . ... . . . . . .. . . . ... ... . 89
Suggested Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 100