1. Chapter 8: Sampling, Standardization & Calibration
CHE 321: Quantitative Chemical Analysis
Dr. Jerome Williams, Ph.D.
Saint Leo University

2. Overview
Sampling
Standardization
Calibration

3. Sampling
Sampling is one of the most important operations in a chemical analysis.
Only a small fraction of available sample is used; therefore, it must be representative of the bulk material.

4. p153

5. Sampling Analytical methods distinguished by
1. type of analysis (qualitative vs. quantitative)
2. Sample size
3. Level of the constituents

6. Figure 8-1 p154

7. Figure 8-2 p154

8. Figure 8-3 p155

9. Sampling
Sampling is the most difficult step in the entire analytical process for it limits the accuracy of the procedure.
Particularly true if sample is large and heterogeneous.
How do we process the sample?

10. Figure 8-4 p156

11. Sampling
Sampling is one of the most important operations in a chemical analysis.
Only a small fraction of available sample is used; therefore, it must be representative of the bulk material.

12. Sampling Goal Sampling Process = obtain random sample
Composition of gross sample and laboratory sample must closely resemble the average composition of the total mass of material to be analyzed.

13. Sampling
Sampling uncertainties (errors) are uniquely different from systematic and random errors.
Preparing Laboratory Samples

14. Figure 8-6 p162

15. Sampling Types of Sampling Methodology Zoning & Quartering
Conveyor Belt Technique
Automated Sampling
Batch (Discrete) Approach
Continous Flow Approach