Basics of sample and sampling chemistry .pptx

this ppt belongs to sampling basic process for Natural product scientist

1. Sample and Sampling

2. Sample Small representative portion of bulk material Types of Sample Solid Liquid Gas

3. Solid Sample Grind the material decrease its particles size Then mix it to ensure its homogeneity Storage Store properly because absorption and adsorption change the Conc.

4. Liquid Sample It should be in one phase Storage Store properly because liquid could be evaporate And it may change the Conc.

5. Gaseous Sample Gases are generally more homogenous than liquid and solid Storage Sample container, may be kept in second sealed container, to ensure the conc. Of gas should be intact

6. Gross Sample consists of several portion of the material to be tested Laboratory Sample consists of a small portion of gross sample made homogenous Analysis Sample is that which is actually analyzed Types of Samples Gross Sample Laboratory Sample Analysis Sample (Few g to Kg) Bulk of Material (Few g) (a drop, few mg, few mL)

7. Classification of Analysis on the Basis of Size of Sample Macro Analysis Large quantities of the sample are used Measurement: 0.1g or more Semi-micro Analysis Lower quantity than macro analysis Measurement: 0.01-0.1g Micro Analysis Small in quantity Measurement: 0.001-0.01g Ultra-micro Analysis More smaller in quantity Measurement: less than 0.001g

8. Sampling is the process of by which we collect a representative portion or small amount of material that accurately represent the bulk of the material being analyzed (We can not analyze the whole thing!) Important Consideration in Sampling It should be a Homegenous for absolute accuracy Sample must be consist of the entire body of material Size of sample (for liquid in mL) (for solid in mg or gm) Select independent method of sampling to minimize the possibility of errors Homogenous Sample: has the same proportions of its components throughout a given sample Heterogeneous Sample: are ones in which their constituents do not mix uniformly

9. Sample Preservation Sample Preparation Analysis Sampling Collect sample Reduce Gross sample to Lab sample Analysis Sample (Gross Sample) (Laboratory Sample) (a drop, few mg, few mL) Steps involved in a measurement process Identify Pop u Steps involved in Sampling process (Bulk)