地膜使用年限对遵义市烟田土壤和烟叶邻苯二甲酸酯累积的影响

研究地膜使用年限对土壤和烟叶邻苯二甲酸酯(PAEs)积累的影响,以明确地膜持续使用条件下PAEs的土壤污染分布特征及在烟叶中的富集状况.在遵义市连阡村和沙湾村采集了不同覆膜年限的烟田土壤及相应的烟叶,采用气相色谱仪质谱联用技术(GC-MS),对土壤-烟叶中6种优先控制PAEs含量进行了测定.结果表明: 所有土壤和烟叶样品中6种邻苯二甲酸酯化合物累计(∑PAEs)分别为(2.66±0.60)和(3.58±0.64) mg·kg^-1,其中,邻苯二甲酸二(2-乙基己)酯(DEHP)含量最高,邻苯二甲酸正二丁酯(DBP)次之,二者之和分别占土壤和烟叶∑PAEs的92.7%和88.9%.DEHP、DBP、邻苯二甲酸二乙酯(DEP)和邻苯二甲酸丁基苄基酯(BBP)检出率均为100.0%,邻苯二甲酸二甲酯(DMP)的检出率略低,邻苯二甲酸正二辛酯(DnOP)检出率最低.随着地膜使用年限的增加,土壤和烟叶中PAEs含量显著增加,且在地膜使用的前1~ 8年增加更为明显,后期趋于平缓.土壤和烟叶中的PAEs含量与覆膜年限呈显著正相关关系,覆膜年限的增加会显著促进土壤和烟叶中PAEs的积累.烟叶与土壤之间∑PAEs的累积量相关性不显著.

Effects of mulching duration on PAEs accumulation in soil and tobacco leaves in Zunyi,China

We examined the effects of the duration of plastic film mulching on the accumulation of phthalate (PAEs) in soils and tobacco to determine the soil pollution distribution characteristics of PAEs under continuous mulch use and the enrichment status in tobacco leaves. Samples of both soils and tobacco leaves were collected from Lianqian Village and Shawan Village of Zunyi. Gas chromatography-mass spectrometry (GC-MS) was used to determine the contents of six preferentially controlled PAEs in samples. The results showed that the six ΣPAEs in all soil and tobacco samples were (2.66 ±0.60) and (3.58±0.64) mg·kg^-1, of which the content of DEHP was the highest, followed by DBP, with the sum of those two accounting for 92.7% and 88.9% of ∑PAEs in the soil and tobacco, respectively. The detection rates of DEHP, DBP, DEP, and BBP were 100.0%. The detection rate of DMP was slightly lower, and that of DnOP was the lowest. The content of PAEs in soils and tobacco leaves significantly increased with the increases of mulching years. In the 1-8 years of film mulching, the increases of PAEs were more obvious and tended to be gentle in the later stage. The content of PAEs in soil and tobacco leaves had significant positive correlation with the years of film mulching, indicating that the increase of film mulching years could significantly promote the accumulation of PAEs. There was no significant correlation between the ∑PAEs accumulation between tobacco leaves and soil.