Analysis of Organophosphate Esters in Dust, Soil and Sediment Samples Using Gas Chromatography Coupled with Mass Spectrometry

Background contamination is a major problem in the analysis of organophosphate esters (OPEs). In this study, the possible sources of OPEs pollution were screened, and several different ways were applied to minimize the blank contamination. Under the strict quality control conditions, the cleanup efficiency of different solid phase extraction (SPE) was investigated. On the basis of this, a method was developed for the determination of 7 OPEs in dust, soil and sediment samples by gas chromatography coupled with mass spectrometry (GC/MS). The target compounds were extracted by hexane-dichloromethane (1:1, V/V) followed by aminopropyl silica gel SPE column cleanup for dust, and target compounds in soil and sediment were Soxhlet extracted and cleanuped by two-step SPE. The results showed that aminopropyl silica gel SPE column displayed the best purification performance among the three employed columns. Instrumental detection limits of the 7 OPEs ranged from 2.5 to 25.8 μg L−1, and method limits of quantification (MLOQs) in dust and soil sample ranged from 1.4 to 15.7 ng g−1 and 0.3 to 2.9 ng g−1, respectively. The average recoveries of 7 OPEs in different matrices (dust and soil) at two spiked concentration levels ranged from 67.9% to 117.4%. The proposed method was successfully applied to analyze OPEs in different environmental samples collected in Shanghai.

Due to the complexity and high organic content, it is difficult to clean and separate the OPEs from the environmental samples. In this study, SPE columns with different sorbent were studied for the cleanup step. The best cleanup method was found to be combined assembly silica column with aminopropyl-silica for soil and sediment. Meanwhile, a one step aminopropyl-silica SPE cleanup was suitable for the determination of 7 OPEs in dust samples.Figure optionsDownload full-size imageDownload as PowerPoint slide