Residue Of Typical Pesticide Adjuvants In Hohhot Suburb Soil And The Ecological Risk Assessment

China has implemented the pesticide registration and management for over twenty years, which has focused on the management of pesticide active ingredients. In recent years, a good deal attention has been paid to environmental problems caused by pesticide adjuvant as one of the main active ingredients of pesticide. Both bisphenol A (BPA) and nonylphenol (NP) are pesticide adjuvant, also typical environmental endocrine disruptors. The distribution characteristics of bisphenol A and nonylphenol in the environment medium and its ecological risk is becoming a hot spot of research in recent years. Octachlorodipropylether(S-421) as another typical pesticide adjuvant, has got extensive attention for its exceeding standard in the exports of tea.In this paper, Hohhot, the capital city of Inner Mongolia Autonomous Region was selected as the study area of farmland on the outskirts. We took the bisphenol A, nonylphenol and octachlorodipropylether as research object, the liquid-chromatography and gas-chromatography were utilized for the determination of residual characteristics of the bisphenol A, nonylphenol and octachlorodipropylether in the farmland surface soil in the study area, and we also discussed the possible influencing factors and carried out the assessment of preliminary ecological risk.This paper mainly achieved the following results:1. The enrichment and analytical method of bisphenol A(BPA), nonylphenol(NP) and octachlorodipropylether(S-421) was established. Under the optimized conditions, the standard adding recoveries of BPA and NP in soil samples with the simultaneous extraction of ultrasonic extraction-liquid chromatography method were 87.26% and 82.89%, the detection limit was 0.11 ng·g-1 and 0.36 ng·g-1 respectively. the standard adding recoveries of S-421 in soil samples with ultrasonic extraction - gas chromatography method was 83.29%, the detection limit was 0.14 ng·g-1. All these can meet the analytical requirement of trace component.2. Residue analysis showed:The detection rate of bisphenol A in study area soil was 66.7%, the concentration ranged from ND to 11.93 ng·g-1, the variable coefficient was 0.991 with greater volatility and the space distribution trend presented lower Southwest and higher Northeast. The detection rate of nonylphenol in study area soil was 100%, the concentration ranged from 9.88 to 45.40 ng·g-1, the variable coefficient was 0.459. The space distribution presented higher northwest and southeast, while low intermediate residues like an uneven saddle. The detection rate of octachlorodipropylether in study area soil was 50%, the concentration ranged from 0.16 to 0.99 ng·g-1, the variable coefficient was 0.67 and the space distribution presented lower from north to south. Soil organic matter content had a significant correlation with soil residue of nonylphenol and octachlorodipropylether. The correlation coefficient were 0.720** (p=0.01) and 0.899* (p=0.05) respectively. Compared with the study in 2010, the residual levels of bisphenol A had significantly increased, the amount of nonylphenol and octachlorodipropylether had a slight decrease and exogenous inputs exist persistently.3. Ecological Risk assessment showed:The RQ value of bisphenol A in the farmland soils in study area was between 0.35 and 1.27. There was one point with a greater ecological risk. The RQ value of nonylphenol in study area was between 0.26 and 1.20 and there were three points to be taken appropriate risk mitigation measures. The remaining points of bisphenol A and nonylphenol need continue observation. The octachlorodipropylether in study area was considered relatively safe initially.