Persistence and biodegradation of four common isomers of benzene hexachloride in submerged soils
Persistence and biodegradation of four common isomers of benzene hexachloride in submerged soils
复制标题
六氯化苯四种常见异构体在沉水土壤中的持久性和生物降解
DOI：
10.1021/jf60153a030
复制
发表时间：
1967
影响因子：
6.1
通讯作者：
T. Castro
中科院分区：
文献类型：
--
作者：
I. C. Macrae;K. Raghu;T. Castro
材料和方法六六六的持久性。本文测定了六氯化苯四种常见异构体在菲律宾吕宋岛两种土壤中的持久性。气相色谱分析表明，每种异构体都不含其他异构体。空气干燥的土壤（Maahas粘土。pH 6.6，有机质2.0%，全氮0.14%，赤红壤，卢伊西亚纳粘粒，pH 4.7，有机质。3.2%，总氮0.21%）过筛（2毫米直径），以20克的量置于大试管中，淹没以提供一个静止的水柱（7厘米），用棉花塞住将装有土壤样品的试管分成两个系列，以便进行两种不同的处理。在第一个处理中，土壤样品仅接受300 gg的苯六六六的一种异构体。每20克土壤。第二系列接受所有四种异构体（300 gg.每20克土壤的每种异构体）。将单独称重的苯六氯环己烷异构体样品作为干燥结晶材料加入到含有这些油的管中的静置水中。为了评估生物降解的重要性，在损失的四个异构体的苯六六六淹没土壤，消毒样品的两种土壤的制备和处理以相同的方式作为nonsterilized土壤。将湿润土壤的浅层在121 ℃下高压灭菌。连续三天，每天1小时。将含有经处理的土壤样品的管置于含有浸水土壤的盆中，使得管和盆中的土壤和水面重合，并且在实验期间将盆保持在温室中。在温室中培养0、15、30、50、70和90天后，取出每个处理的三个重复管，从土壤中提取苯六氯环己烷，并通过气相色谱法定量测定土壤中残留的每种异构体的量。
MATERIALS AND METHODSPersistence of BHC. The persistence of the four com-mon isomers of benzene hexachloridein two soils of Luzon (Philippines) was determined. Gas chromato-graphic analysis revealed that each isomer was free of the other isomers. The air-dried soils (Maahas clay. pH 6.6, organic matter 2.0%, total N 0.14% and a latosolic soil, Luisiana clay, pH 4.7, organic matter. 3.2%, total N 0.21%) were screened (2-mm. diameter), placed in large test tubes in 20-gram amounts, flooded to provide a column of standing water (7 cm.), and plugged with cotton. The tubes containing the soil samples were divided into two series so that two different treatments could be made. In the first treatment the soil samples received only one iso-mer of benzene hexachloride at the rate of 300 gg. per 20 grams of soil. The secondseries receivedall four isomers (300 gg. of each isomer per 20 grams of soil). Separately weighed samples of the isomers of benzene hexachloride were added as the dry crystalline material to the standing water in the tubes containing thesoils. To evaluate the significance of biodegradation in losses of the four isomers of benzene hexachloride from submerged soils, sterilized samples of the two soils were prepared and treated in the same way as the nonsterilized soils. Shallow layers of the moistened soils were sterilized by autoclaving at 121c C. for 1 hour on each of three successive days. The tubes containing the treated soil samples were placed in pots containing flooded soil so that the soil and water-surfaces in the tubes and pots coincided, and the pots were kept in the greenhouse for the duration of the experiment. After 0, 15, 30, 50, 70, and 90 days’ incubation in the greenhouse, three replicate tubes of each treatment were withdrawn, the benzene hexachloride was extracted from the soils, and the amount of each isomerremaining in the soils was determined quantitatively by gas chromatography.