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黄河水体喾物对敌百虫和甲拌磷的吸附 总被引:1,自引:0,他引:1
对敌百虫和甲拦磷在黄河水体喾物中的吸附特性进行了研究,观察了pH值和离子强度等因素对吸附的影响,结果表明,敌百虫的吸附过程为一级动力学规律;敌百虫的吸附符合Langmuir等温式,甲拌磷的吸附可用Freundich等温式较好地描述,pH值降低或离子强度增加使敌百虫和甲拦磷在沉积物中的吸附程度明显减小,敌百虫在黄河水体沉积物中的吸附以表面吸附为主,而甲拦磷则表现为表面吸附和在有机磷中的分配作用两种吸附方式。 相似文献
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黄河水体沉积物对敌百虫和甲拌磷的吸附 总被引:8,自引:0,他引:8
对敌百虫和甲拌磷在黄河水体沉积物中的吸附特性进行了研究,观察了pH值和离子强度等因素对吸附的影响.结果表明,敌百虫的吸附过程为一级动力学规律;敌百虫的吸附符合Langmuir等温式,甲拌磷的吸附可用Freundich等温式较好地描述.ph值降低或离子强度增加使敌百虫和甲拌磷在沉积物中的吸附程度明显减小.敌百虫在黄河水体沉积物中的吸附以表面吸附为主,而甲拌磷则表现为表面吸附和在有机碳中的分配作用两种吸附方式. 相似文献
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有机磺酸类化合物的络合萃取研究 总被引:15,自引:0,他引:15
本文以三烷基胺为络合剂,正辛醇,煤油,氯仿,四氯化碳等为稀释剂,测定了络合萃取剂对于对甲基苯磺酸,磺基水杨酸稀溶液的相平衡分配系数,讨论了稀释剂,体系PH值和7301络合剂含量对萃取相平衡分配系数D值的影响,确定了形成的萃合物的组成。 相似文献
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环境样品中乙虫腈及其代谢产物残留量分析 总被引:2,自引:0,他引:2
采用加速溶剂萃取提取、florisil固相萃取小柱净化,建立了环境样品中乙虫腈农药及其代谢产物的气相色谱(电子捕获检测器)测定方法.试验结果表明,土壤、水稻植株、稻壳和稻米中乙虫腈及其代谢产物的最低检测量为0.0l mg· kg-1,稻田水中为0.01 mg·L-1.在该方法条件下,稻田水、土壤、水稻植株、稻壳和糙米中乙虫腈及其代谢产物的平均回收率为72.8%~103.6%,相对标准偏差为1.3%~12.5%. 相似文献
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NaOH溶液对有机相苯酚反萃取的研究 总被引:8,自引:0,他引:8
本文系统进行了NaOH溶液对负载苯酚的TBP+煤油溶剂的反萃取平衡实验。考虑苯酚的支萃取平衡和解离平衡,建立了反萃取的计算模式,并证明了模型的可行性。本文还讨论了NaOH溶液浓度,油水相比,萃取平衡分配系数,溶剂中的负载苯酚浓度和NaOH溶液中初始酚含量对反萃取率的影响。 相似文献
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使用加速溶剂萃取仪萃取环境样品中的多环芳烃(PAHs) 总被引:2,自引:0,他引:2
《环境化学》1997,(6)
加速溶剂萃取技术(简称ASE)是一种全新的高效样品前处理方法,常用的有机溶剂由泵注入已填充样品的萃取池后,加温加压,数分钟后,萃取液由载气吹入收集瓶中,萃取过程全部自动化,且可多次萃取,快速省时,溶剂消耗量少。 相似文献
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使用加速溶剂萃取提取环境样品中的多氯联苯 总被引:4,自引:0,他引:4
《环境化学》1997,16(5):495-496
加速溶剂萃取(简称ASE)是一种全新的萃取方法.它可以显著提高样品前处理的速度.溶剂被泵入填充有样品的萃取池后,加温、加压,数分钟后,萃取物从加热的萃取池中输送到收集瓶中供分析用.萃取步骤全程自动化,时间短,溶剂消耗少.可以代替溶剂消耗量很大的索氏萃取和超声波萃取. 相似文献
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AbstractA rapid and selective technique for extraction, preconcentration and determination of trace amounts of cobalt in water and pharmaceutical samples by air-assisted liquid–liquid microextraction combined with flame atomic absorption spectrometry is proposed. 1-Nitroso-2-naphthol is used as a complexing agent and 1-octanol as an extraction solvent. Parameters relevant for analytical effectivity, i.e. pH of sample solution, concentration of complexing agent, volume of extraction solvent, and number of extraction cycles are optimized using a Box–Behnken design. At optimum conditions, a dynamic linear range of 5–600?µg L?1 is obtained, with a limit of detection of 1.2?µg L?1. The method is used for determination of Co(II) in environmental water and pharmaceutical samples. 相似文献
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分散液液微萃取-石墨炉原子吸收光谱法测定环境水样中的痕量镉 总被引:1,自引:0,他引:1
建立了分散液液微萃取分离富集一石墨炉原子吸收光谱法测定环境水样中痕量镉的新方法。以二乙基二硫代氨基甲酸钠为螯合剂、四氯化碳为萃取剂、丙酮为分散剂,详细考察YpH值、螯合剂质量分数、萃取剂体积、萃取时间等因素的影响。在优化的实验条件下,方法对水样中镉的检出限为4.2ng-L^-1,线性范围是20-300ng-L^-1,测定结果的相对标准偏差为3.5%,富集倍数达103。将建立的方法应用于三种实际环境水样中镉的检测,加标回收率在92%-108%范围内。本方法具有灵敏、准确、快速、环保的特点,是一种分析水样中痕量镉的较好方法。 相似文献
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Determining the relative contributions of intrinsic and extrinsic processes to the regulation of biological populations has been a recurrent ecological issue. Recent discussions concerning ecosystem "regime shifts" again raise the question of whether population fluctuations are mainly controlled by external forcing. Results of nonlinear time series analyses indicate that pelagic populations typically do not passively track stochastic environmental variables. Rather, population dynamics are better described as nonlinear amplification of physical forcing by biological interactions. However, we illustrate that in some cases populations do show linear tracking of the physical environment. To explain why population dynamics can sometimes be linear, we propose the linear tracking window hypothesis: populations are most likely to track the stochastic environmental forcing when their generation time matches the characteristic time scale of the environmental signal. While our observations follow this hypothesis well, our results indicate that the linear tracking window is a necessary but not a sufficient condition. 相似文献
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土壤和沉积物中的聚合有机质对多环芳烃分布和提取的影响 总被引:1,自引:0,他引:1
为了研究土壤和沉积物中凝聚型有机碳(碳黑、干酪根)的含量及其对多环芳烃(PAHs)分布和提取的影响,分别用三氟醋酸(TFA)和在375℃下通氧燃烧的方法从珠江三角洲2个污染土壤和5个河口沉积物样品中提取酸非水解有机碳(NHC)和碳黑(BC);用索氏抽提法和不同溶剂的加速溶剂萃取法(包括连续加速萃取法ASESum和标准溶剂萃取法ASESTD)抽提土壤和沉积物中的多环芳烃,并在不同温度梯度(25℃到150℃)下用水为溶剂加速溶剂萃取其水溶态.结果表明,1)NHC是珠江三角洲土壤和沉积物中总有机碳的重要组成部分,NHC碳明显高于BC碳,NHC和BC分别占土壤和沉积物中有机碳的25.6% ̄73.8%和4.64% ̄17.3%.2)3种有机溶剂(丙酮、甲苯1、甲苯2)连续抽提的PAHs含量是索氏抽提的2.11倍;5种ASE方法(丙酮、甲苯1、甲苯2、ASESum、ASESTD)提取的PAHs含量与NHC含量存在明显的相关性,而且比PAHs含量与BC或无定型有机碳(AOC)含量的相关性更明显.3)在不同温度梯度下水溶态PAHs浓度符合Van’tHoff方程.研究说明除了BC外,非水解有机碳对土壤和沉积物中PAHs的分布和提取具有重要影响. 相似文献
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Christina Vakh Ekaterina Evdokimova Alexey Pochivalov Leonid Moskvin Andrey Bulatov 《毒物与环境化学》2017,99(4):613-623
The novel and simple methods for the sensitive determination of cationic and anionic surfactants in water based on effervescence assisted dispersive liquid–liquid microextraction and microvolume UV-Vis spectrophotometry have been developed. The method involves ion-pair extraction of cationic and anionic surfactants with organic dyes (methyl orange and azure A, respectively) during the dispersion of extraction solvent (CHCl3) by CO2 bubbles which are formed by the injection of a mixture of the extraction solvent and proton donor solvent into the sample solution which contains carbonate-ions as effervescency agent. The analytical performance of the proposed procedure was compared with the conventional dispersive liquid–liquid microextraction. Appropriate experimental conditions for both methods were investigated. The absorbances of the colored extracts at wavelengths of 440 and 625 nm obey Beer's law within the range of 0.1–5.0 mg/L for both cationic and anionic surfactants. The limit of detection (LOD) obtained using the effervescence assisted extraction method was 30 µg/L for cationic and anionic surfactants. The proposed methods were successfully applied to determination of surfactants in water samples. 相似文献