Learning objectives
Understand the concepts related to different sampling approaches and sample pre-treatment techniques in food, toxicology and forensic fields. Knowledge of the advantages/disadvantages of these techniques. Choose of the best procedure for the achievement of reliable results.
Capacity of data interpretation. Understand and interpretate an analysis report, including the used sampling and pre-treatment approaches and the obtained results.
Prerequisites
- - -
Course unit content
Introduction to principles and procedures to be used to obtain a representative sample. Study of different sampling in different fields, including food industry, packaging and forensic analysis. Evaluation of different sample extraction, pretreatment, and clean-up techniques. Case studies and discussion of advantages/disadvantages of sample pretratment techniques for food, forensic, clinical and toxicological analysis.
Full programme
Introduction about the analytical process. Sampling and sample treatment: critical parameters. Sampling of food matrices and forensic analysis, sample treatment and storage conditions. Criteria for the extraction of the analytes from food, clinical and forensic samples: evaluation of extraction efficiency, selectivity and matrix effect. Use of clean-up approaches after sample extraction: principles and when to apply.
Sampling
Definition of batch, elemental sample, incremental sample, lab sample. Sampling plan. Criteria beyond the choice of a sampling strategy. Current legislation in food and packaging sampling. Discussion of examples and case studies
Sample pretreatment for elemental analysis: mineralization using wet digestion and microwave digestion
Techniques for the analysis of volatile and semi-volatile compounds.
Static head-space (HS)
Dynamic headspace (DH)
Purge-and-trap (P&T)
Extraction techniques for non volatile compounds: Dispersive liquid-liquid microextraction (DLLME), solid-phase extraction (SPE), microwave extraction (MAE), supercritical fluid extraction (SFE), dispersive solid-phase microextraction (D-SPME), accelerated solvent extraction (ASE), Molecularly imprinted membranes (MIMS), microextraction by packed sorbent (MEPS), stir-bar solid phase extraction (SBSE)
Advantages and drawbacks compared to classical extraction techniques (liquid-liquid, solid-liquid, Soxhlet)
Case studies: examples and discussion
Bibliography
National and international legislation; reviews available in elly;
text:
Somenath Mitra, Sample Preparation Techniques in Analytical Chemistry, Print ISBN:9780471328452 |Online ISBN:9780471457817 |DOI:10.1002/0471457817, 2003 John Wiley & Sons, Inc.
Teaching methods
The course develops in 48 hours of frontal teaching during which the students are guided to the understanding of sampling and sample pretreatment.
The students have to partecipate to the discussion in order to be able to select the proper method for specific applications
Assessment methods and criteria
Oral examination to verify the acquisition of basic concepts related to sampling and sample pre-treatment for the right choice of analytical methods.
Other information
Educational material is available to the students on ELLY until March 1st 2025
