| Organophosphorus triesters (OPEs) are a kind of phosphorous flame retardants andwidely used in polyvinylchloride, polystyrene, polyurethane foams, rubber and paints.The widespread usage and the diffusion from host materials result in continuousrelease of OPEs and their distribution in water, air and human body. Considering theproperties and toxic effects of OPEs, European Union had classified chlorinated-alkylphosphates as substances of very high concern.Urban soils and dust are complex environmental carriers acting as sink and sourceof pollutants, but few researches about OPEs in urban environment are reported. Toinvestigate the pollution status of OPEs in Guangzhou urban soils and dust, firstly ananalytical method for OPEs was found, covering ethyl acetate Soxhlet extraction,alumina-silica column clean-up procedures, as well as the determination by GC-MS.The distribution characteristic of OPEs in urban soils and dust of Guangzhou citywere measured by this method under quality assurance (QA) and quality control (QC).Results are as follows.1. Analytical method for OPEs(1) This method can decrease the level of co-extracted interferences from urbansoils and dust matrices. Besides TMP and TEP, the average recoveries were 64.2 % ~91.7%, the determination limits detections were 0.09 ~ 3.28 ng/g, and the relativestandard deviations were 1.91 % ~ 14.9 % for OPEs. 2. Distribution characteristics of OPEs in surface soils of Guangzhou city(1) TheΣ12OPEs concentration in Guangzhou surface soils ranged from 42.97 to1361 ng/g, with the average concentration of 265.2 ng/g. Significantly highconcentrations ofΣ12OPEs in urban soils were observed from industrial district,refuse transfer station and roadsides. Diffusion from OPE-containing products, addedto the emission from motor vehicle and the daily refuse may be the main source ofOPEs in urban soils.(2) TEP, TBP, TBEP, EHDPP, TEHP, TCEP, TCPP, TPhP, TCrP and TPPO werepresent in most soil samples. TBEP and TCrP were abundant in Guangzhou urbansoils. Significantly different OPE compositions were observed, and low correlationswere not only found within OPEs (excepr for TCrP, TBP, TDCP, TBEP and TEHP),but also found between TOCs and OPEs concentrations, which attributed to thediversity of potential inputs from local sources.3. Distribution characteristics of OPEs in road dust of Guangzhou city(1) Distributions of road dust in＞380μm, 150 ~ 380μm, 106 ~ 150μm, 75 ~106μm and＜75μm fractions were 6.56% ~ 25.6%, 50.5% ~ 63.7 %, 13.3% ~29.7%, 3.11% ~ 8.97% and 0.825% ~ 8.11% respectively. Similar size-fraction werefound in different districts of Guangzhou city.(2) TheΣ12OPEs concentration in Guangzhou urban dust ranged from 0.558 to3.553μg/g, with the average concentration of 1.540μg/g. Significantly highconcentrations ofΣ12OPEs in urban soils were observed from commercial district andheavy traffic highway, which may attributed to exhaust emission, leakage oftransmission oils/lubricants and widely use of OPE-containing products.(3) 12 OPEs were present in most dust samples and TBEP and TCrP were thepredominant OPEs in urban dust. Similar OPE profiles were found in road dust ofdifferent districts of Guangzhou city.(4) OPEs tended to be more abundant in small size-fractionated dust, approximately58% ofΣ12OPEs, 65% of alkyl phosphates, 70% of aryl phosphates (except for SunYat-san University), 63% of chlorinated-alkyl phosphates and 56% of TPPO were present in＜150μm fractions. Except for＞380μm fraction, similar OPE profileswere found in different size-fractionated road dust, in which TBEP and TCrP were thepredominant OPEs.(5) Significantly positive correlations were found within aryl phosphates andchlorinated-alkyl phosphates. However, low correlations were found between TOCsand OPEs concentrations in the road dust, which may attributed to different sources ofOPEs. |
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