This chapter deals with all critical steps before near-infrared spectroscopy (NIR) analysis, irrespective of whether the total sampling error contribution is large, intermediate, or small – all cases can be treated identically, including the widespread sensor-based solutions from the process and Process Analytical Technology realm. The key issue of “sampling” is lot heterogeneity and how to counteract its adverse influence on sampling/signal acquisition, subsampling, and sample preparation/presentation processes. The Theory of Sampling (TOS) is the guiding framework for valid analysis, including NIR spectroscopy, because this alone can help to eliminate or reduce maximally all such adverse influences. The chapter presents the minimum TOS competence needed to be scientifically, technically, and managerially responsible for guaranteeing relevant, meaningful, and reliable analytical results in all contexts, under all circumstances and for all types of materials that can be subjected to NIR analysis – illustrated by a set of generic sampling solutions and case examples from typical application fields within the NIR realm.

• KHE Consulting
• The University of Puerto Rico at Mayagüez (UPRM)

• PAT
• Oral solid dose

1. generic sampling solution
2. NIR spectroscopy
3. oral solid dose
4. Other
5. pat
6. Theory of sampling