Accurate determination of pesticides, hormones and endocrine disruptor compounds in complex environmental samples using matrix dilution and matrix matching with dispersive liquid-liquid microextraction

Quantitative determination of contaminants in environmental samples is usually hampered by low analyte recovery which results from the complex nature of the sample matrix. This study presents the application of a developed dispersive liquid-liquid microextraction method for the determination of 12 analytes in environmental samples including sea water, fresh water (lake, well and tap water), brackish water and soil samples. Matrix matched standards were used to compensate for the low analyte recovery recorded by the conventional calibration method. The effect of matrix dilution on analyte recovery was also tested. All matrix matched and matrix diluted spiked recoveries were done concurrently with calibration standards prepared in deionized water. Percent recoveries recorded for the analytes according to deionized water calibration standards ranged between 66 and 137 %. Matrix matching and matrix dilution yielded close to 100 % recovery results, but the later lowered the detection limit according to the dilution factor.