Modern qualitative analysis by miniaturized and microfluidic systems

• Qualitative analysis in miniaturized and microfluidic analytical systems.
• Progress in identification of compounds by miniaturized and microfluidic systems.
• Recent progress in screening samples by miniaturized and microfluidic systems.
• Selected applications in clinical, food, and environmental fields.
• Advantages and disadvantages of qualitative analysis in miniaturized systems.

The evolution toward miniaturization has affected many facets in our life and similarly is also a clear trend in modern analytical science and laboratories, resulting in miniaturized devices and measurement processes with interesting, advantageous practical implications. This article presents a general view of miniaturized analytical systems, covering devices giving qualitative information. Qualitative information is more than the simple identification of compounds in samples, as the modern concept of qualitative analysis also includes the analytical information not represented by numbers (as is characteristic of quantitative analysis). Thus, classification of samples by screening methods, or the definition of an analytical profile of analytes in a sample, as diagnostic tests provide, must be viewed as a type of qualitative analysis. Following this concept of qualitative analysis, different miniaturized analytical approaches are described, as are future trends, pointing out advantages, disadvantages and challenges.