Synthesized modified silica gel for extraction and pre-concentration process of ultra trace amounts of lead (II) ion in lettuce and water samples, using solid phase extraction method

In recent decades, the issue of crop product safety has led to develop methods for analyzing pollutants in crops. In the present study, ultra-trace amounts of lead (II) ions were measured in lettuce and water samples collected from Shahmirzad, located in Semnan province, an area known for its lead-containing mineral mines.

After sampling and pre-preparation, the lead content in each sample was extracted using solid phase extraction with modified silica gel. The recovery percentage of lead was then determined using atomic absorption spectroscopy.

Optimization of key parameters such as pH, adsorbent amount, analyte flow rate, and volume resulted in a recovery rate of 104%. The experiments also demonstrated a very low limit of detection (LOD) of 1.14 ng/mL, a concentration factor of 250, high analyte selectivity of the adsorbent in the presence of interfering ions, and a high adsorbent capacity of 2.93 μg/g.

The evaluation of experimental data indicates that the current study provides a highly selective method that can be applied to the extraction and recovery of various analytes from different sample types.