Guidance On Obtaining Defensible Test Portions: Subsampling for Analytical Laboratories
September 7-8, 2019 • 9 am to 5 pm • Fee: US $1,195 (2-day course)
The means by which chemists and microbiologists apportion laboratory samples prior to testing can drastically affect the reliability of the results. For example, some may open a sample container and just scoop or pour a small portion of material off the top whereas others may try to obtain material from different parts of the sample for laboratory analysis. Others still may stir the sample first or employ some type of coning and quartering. Such practices may not adequately represent the material and thus introduce both random and systematic errors into the measurement process. In this course, participants will learn how to properly take a representative subsample for laboratory analysis. In addition, the crucial connection between primary sampling and laboratory subsampling will be investigated to bring efficiency and defensibility to the entire sampling and analytical process.
This course incorporates concepts from the documents Guidance On Obtaining Defensible Samples
and Guidance On Obtaining Defensible Test Portions
. The attendees will have an opportunity to ask technical questions about the material presented and specific questions about subsampling situations they have encountered.
Sample Quality Criteria and its importance in subsampling
- The Decision Unit and why it is critical for subsampling
- Where subsampling errors originate and how to mitigate them
- Why certain subsampling tools may bias samples
- How to choose and correctly use subsampling tools and equipment
- How to design cost effective subsampling protocols to achieve project goals
- Why replicate samples yield different analytical results
- How to properly split a sample
- Why “outliers” should not always be discarded
- How to measure subsampling error
- How to perform proper subsampling quality control
- How to increase confidence in analytical results through error reduction
- Data evaluation and decision making issues resulting from poor subsampling
Read both GOODSamples and GOOD Test Portions prior to the course.
Available free at: https://www.aafco.org/Publications
Back to the Top