Pesticides, phenols, phthalates, and organotins were heavily used and polycyclic aromatic hydrocarbons (PAHs) were widely generated from air pollution, such as transportation and combustion. All the above chemicals may run off via rain or air deposition to the river, ground water, sediment, and soil. Since most conditions in soil and sediment are anaerobic, the above compounds may exist in the environment persistently; consequently, the residue level in soil or sediment may represent a long term trend of pollution. Although there are some existing methods available on analyzing these compounds, there is none can analyze these groups together.
This study developed a method for detecting 79 important environmental pollutants, including 11 organophosphates, 5 carbamates, 7 pyrethroids, 8 phthalates, 16 phenols, 24 PAHs (containing the 16 EPA priority PAHs), and 8 organotins, in soil and sediment, using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and gas chromatography tandem mass spectrometry (GC-MS/MS). Soils and sediments samples were treated with QuEChERS and the extracts were analyzed using UPLC-MS/MS with electrospray ionization (ESI) for insecticides, phthalates, and organotins, and atmospheric pressure photoionization (APPI) with post-column addition of anisole as a dopant for PAHs; phenols were analyzed with GC-MS/MS using electron ionization (EI). Data acquisition were at multiple-reaction monitoring (MRM) mode with monitoring two ion transitions at each analyte, and the quantitation were done with isotope-dilution techniques.
The limits of detection of soil and sediment ranged most from few to tens of ng/g (wet weight) and 30 to 180 ng/g (wet weight). The square of regression coefficients (r2) of calibration curves were higher than 0.990. The matrix effect factors of analytes were most between 70-130%, and the use of isotope-labeled internal standards can cancel out the effects on quantitation resulting from matrix effects or variations of extraction efficiency, then reached good recoveries (most between 75-130%). For method validation, 40 real samples were analyzed, including 16 river sediments, two sludge from a water treatment plant, four sediment samples from two harbors, 13 soil samples around rivers, and 5 soil samples from industrial parks. Among the analytes, phthaltes and PAHs were in higher positive rates in the real samples. This study established the initial precision and recovery (IPR) and two drafts of standard analytical procedures for the National Institute of Enviromental Analysis.