Chemical Sample Analysis Techniques and Classification
Obtaining the Sample for Analysis
Constituent Concentration Levels
The classification of constituents within a sample is based on their concentration relative to the total sample mass:
- Major Constituent: More than 1% of total.
- Secondary Constituents: 0.1% to 1% of total.
- Trace Level: Less than 0.1% of total.
- Ultratraces: Parts per million (ppm) level.
Classification of Analytical Methods by Sample Size
Sample Weight and Volume Requirements
Analytical methods are categorized based on the required sample weight (mg) and volume (ml):
- Macroanalysis: Higher than 100 mg; requires 10 ml or more.
- Semimicroanalysis: 10–100 mg; requires 1–10 ml.
- Microanalysis: 1–10 mg; requires 0.1–1 ml.
- Ultramicroanalysis: Less than 1 mg; requires under 0.1 ml.