广东省典型区域农业土壤中邻苯二甲酸酯含量的分布特征

Distribution of phthalic acid esters in agricultural soils in typical regions of Guangdong Province

采用气相色谱方法,对广东省典型区域农业表层土壤(0～20cm)样品中的6种邻苯二甲酸酯(PAEs)进行了测定.结果表明:6种PAEs化合物的总含量(∑PAEs)为nd(未检出)～25.99mg.kg-1,其中92.8%的样品分布在≤1mg.kg-1的范围;各种土地利用类型中∑PAEs的顺序依次为水田>香蕉地>菜地>甘蔗地>果园地;不同地区土壤中∑PAEs的顺序依次为东莞市>汕头市>佛山市顺德区>湛江市>中山市>珠海市>惠州市.邻苯二甲酸二(2-乙基已基)酯(DEHP)的检出率最高(85.1%),邻苯二甲酸二正丁酯(DnBP)含量最高(nd～17.51mg.kg-1).与美国土壤PAEs控制标准相比,除邻苯二甲酸二正辛酯(DnOP)外,其余5种PAEs化合物均有不同程度的超标,其中DnBP、邻苯二甲酸二甲酯(DMP)和邻苯二甲酸二乙酯(DEP)3种化合物超标率较高.广东省典型区域农业土壤受到不同程度的PAEs污染.

To understand the distribution characteristics of phthalic acid esters （PAEs） in agricultural soils in typical regions of Guangdong Province, surface soil （0-20 cm） samples were collected, and the concentrations of 6 PAEs were determined by gas chromatography. The results showed that the total concentration of the PAEs （ ∑ PAEs） ranged from not detected to 25.99 mg · kg^-1, and was ≤1. 00 mg · kg^-1 in 92. 8% of the samples. The ∑PAEs differed with land use types and regions, and decreased in the sequences of paddy soil 〉 banana soil 〉 vegetable soil 〉 sugarcane soil 〉 orchard soil, and Dongguan 〉 Shantou 〉 Shunde 〉 Zhanjiang 〉 Zhongshan 〉 Zhuhai 〉 Huizhou. Among the test PAEs, DEHP had the highest detection rate （85.1% ）, DnBP had the highest concentration （not detected to 17.51 mg · kg^-1）. Comparing with the corresponding control limits of soil PAEs in USA, all test PAEs except DnOP were exceeded the limits to some extent, and DnBP, DMP and DEP exceeded seriously, indicating that the agricultural soils in the typical regions of Guangdong Province were contaminated by PAEs.