When assessing the enrichment of an element in a sample compared to a background or reference level, it's essential to account for variations in the sample matrix. This is where the concept of a stable element comes into play.

Normalization is the process of dividing the concentration of an element in the sample by the concentration of a stable element in the same sample.

Characteristics of a Stable Element

A suitable stable element should exhibit the following characteristics:

• Abundance: It should be present in sufficient quantities in the sample.
• Stability: Resistant to anthropogenic influences and environmental changes
• Conservative behavior: Its concentration should not be significantly affected by geochemical processes.
• Representative of the lithogenic component: It should be a primary constituent of the sediment.

Commonly used stable elements in enrichment factor calculations include:

• Aluminum (Al): Abundant, resistant to human activities, and a major constituent of clay minerals.
• Iron (Fe): Widely distributed, relatively stable, and a significant component of many minerals.
• Titanium (Ti): Highly resistant to weathering, often used in geochemical studies.
• Zirconium (Zr): Another resistant element, commonly used in soil and sediment analysis.

Additional Considerations

• The choice of stable element depends on the specific study and the elements being analyzed.
• It's essential to justify the selection of the stable element based on its properties and relevance to the study area.
• In some cases, multiple stable elements can be used to cross-validate results.