Kursinformation

Syllabus for the lecture "Sample preparation in analytical chemistry"

In the analytical process, the sample preparation includes the work steps between sampling and measurement, whereby the original samples are to be converted into a measurable state. The lecture is intended to cover the area of ​​organic analytics, in which there is generally an enrichment or concentration of any analytes and a separation of the analytes from the interfering matrix. The step of sample preparation, after sampling, is often the step with the greatest error-proneness. In many cases it is also the most labor-intensive. Therefore, the aim nowadays is to automate, miniaturized and more environmentally friendly (green)sample preparation to a large extent. The lecture is intended to give an overview of the existing classic and modern solvent-free techniques. A focus will be on the physico-chemical parameters that lie behind these methods. As far as possible, methods available at the chair are explained for better practical relevance in the laboratory and shown through handouts in the lecture.

The lecture is an elective course in the Master programs Water Science and Chemistry in the winter semester and comprises 2 SWS (3 CP).

 The course tales place online.

1 Course overview
1.1 Why sample preparation? - Benefits and limitations
1.2 Classic and modern sample preparation methods
1.2 Green Sample Preparation Methods
1.3 Automation of enrichment techniques
2 Evaluation of sample preparation techniques
2.1 Separation factor, enrichment factor, depletion factor
2.2 Extraction Yield
3 Classification of Distribution Processes
4 Separations due to differential distribution between two immiscible phases
4.1 Distribution between two liquids - Nernst distribution theorem
4.2 Solvents - solvent mixtures - synergistic effect - extracted compounds - chemical reactions during distribution
4.3 Poly parameter linear free energy relationships (PP-LFERs)
4.4 Influence of pH on partition equilibria
4.5 Salting Out
4.6 Partitioning
4.7 Perforation
4.8 Single Drop Microextraction (SDME) 
4.9 Liquid Phase Microextraction (LPME)
5 Membrane-Assisted Liquid/Liquid Extraction
5.1 Membrane Assisted Solvent Extraction (MASE)
5.2 Electromembrane Extraction (EME)
6 Dispersive Methods
6.1 Dispersive liquid microextraction (DLME)
6.2 QuEChERS
7 Distribution between liquid and solid phase
7.1 Soxhlet Extraction
7.2 Accelerated Solvent Extraction (ASE), (Pressurized Fluid Extraction PFE)
7.3 Ultrasonic Extraction (USE)
7.4 Microwave Assisted Extraction (MAE)
7.5 extraction temperature above the LM boiling point)
7.6 Supercritical Fluid Extraction (SFE)
7.7 Solid phase extraction (SPE)
7.8 Solid phase microextraction (dSPME)
7.9 Stir Bar Sorptive Extraction (SBSE)
7.10 Thin Film SPME (TF-SPME)
7.11 Micro extraction by packed sorbent (MEPS)
8 Distribution between liquid and gas phase
8.1 Solubility of gases in liquids
8.2 Air-water partition coefficient and Henry's constant
8.3 Static Headspace
8.4 Dynamic Headspace
8.5 Stripping Techniques
8.6 Purge and Trap (P&T)
8.7 Pervaporation
8.8 Direct Solid-Phase Microextraction (hSPME)
8.9 PAL SPME Arrow
9 Adsorption and absorption of gases on solids
9.1 Sorption isotherms
9.2 Sorption materials
9.3 Thermal desorption (TD)
9.4 Headspace SPME (hSPME)
9.5 In tube extraction (ITEX)