Matrix E ffect and Recovery

Matrix e ffects were determined by comparing the peak area of standards in the extracts (A), after evaluation of a sample target, with that of analyte standard solutions (B). The recoveries of the

analytes were determined by comparing the peak area of analytes standard solution (8 ppm) after solid phase extraction (SPE) with that of the analytes' standard solution (8 ppm) before SPE. The ratio (after SPE/before SPE) × 100 was determined.
