The effects of humic substances on the intake of micro-organic pollutants into the aquatic biota

2003 ◽  
Vol 47 (7-8) ◽  
pp. 117-124 ◽  
Author(s):  
J. Matsubara ◽  
J. Takahashi ◽  
K. Ikeda ◽  
Y. Shimizu ◽  
S. Matsui

Humic substances, naturally occurring highly polymerized organic compounds, exist widely in the water and soil environments. It has been known that the humic substances affect the fate of micro-organic pollutants (e.g. intake, accumulation, movement, degradation, toxicity, etc.). Of these, the effect of humic substances on the intake into biota (i.e. living cell) is one of the most important. In this research, the effects of co-existing humic substances on the intake of micro-organic pollutants into aquatic biota were experimentally evaluated. The humic acid filtrate using a 3,000 Da ultra-filtration membrane was used. Two PAHs (i.e. pyrene and phenanthrene) were used as micro-organic pollutants. Liposome for simulating living cell membrane was synthesized in the laboratory, and used for investigating the intake of micro-organic pollutants into aquatic biota precisely. The batch experiment results (PAHs onto humic acid, humic acid into liposome, and PAHs into liposome (Klipw)) led to the fact that the sorption of PAHs into liposome is suppressed apparently by binding with humic acid in the aqueous phase. This suggests that the accumulation and/or toxicity of micro-organic pollutants is retarded by humic substances in the actual aqueous environment. Moreover, the experimental results indicated that the sorption into liposome (i.e. liposome/water partition coefficient (Klipw)) could be a better parameter for estimating the intake of micro-organic pollutants into aquatic biota than n-octanol/water partition coefficient (Kow) in the aqueous environment.

2011 ◽  
Vol 356-360 ◽  
pp. 83-88 ◽  
Author(s):  
Shu Qiao ◽  
Kun Xie ◽  
Chuan Fu ◽  
Jie Pan

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are a group of important persistent organic pollutants. Quantitative structure–property relationship (QSPR) modeling is a powerful approach for predicting the properties of environmental organic pollutants from their structure descriptors. In this study, a QSPR model is established for estimating n-octanol/water partition coefficient (log KOW) of PCDD/Fs. Three-dimensional holographic vector of atomic interaction field (3D-HoVAIF) is used to describe the chemical structures, SMR-PLS QSAR model has been created and good correlation coefficients and cross-validated correlation coefficient is obtained. Predictive capability of the models has also been demonstrated by leave-one-out cross-validation. Moreover, the estimated values have been presented for those PCDD/Fs which are lack of experimentally data by the optimum model.


2009 ◽  
Vol 7 (4) ◽  
pp. 846-856 ◽  
Author(s):  
Andrey Toropov ◽  
Alla Toropova ◽  
Emilio Benfenati

AbstractUsually, QSPR is not used to model organometallic compounds. We have modeled the octanol/water partition coefficient for organometallic compounds of Na, K, Ca, Cu, Fe, Zn, Ni, As, and Hg by optimal descriptors calculated with simplified molecular input line entry system (SMILES) notations. The best model is characterized by the following statistics: n=54, r2=0.9807, s=0.677, F=2636 (training set); n=26, r2=0.9693, s=0.969, F=759 (test set). Empirical criteria for the definition of the applicability domain for these models are discussed.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nadin Ulrich ◽  
Kai-Uwe Goss ◽  
Andrea Ebert

AbstractToday more and more data are freely available. Based on these big datasets deep neural networks (DNNs) rapidly gain relevance in computational chemistry. Here, we explore the potential of DNNs to predict chemical properties from chemical structures. We have selected the octanol-water partition coefficient (log P) as an example, which plays an essential role in environmental chemistry and toxicology but also in chemical analysis. The predictive performance of the developed DNN is good with an rmse of 0.47 log units in the test dataset and an rmse of 0.33 for an external dataset from the SAMPL6 challenge. To this end, we trained the DNN using data augmentation considering all potential tautomeric forms of the chemicals. We further demonstrate how DNN models can help in the curation of the log P dataset by identifying potential errors, and address limitations of the dataset itself.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2995
Author(s):  
Laurynas Jarukas ◽  
Liudas Ivanauskas ◽  
Giedre Kasparaviciene ◽  
Juste Baranauskaite ◽  
Mindaugas Marksa ◽  
...  

Black, brown, and light peat and sapropel were analyzed as natural sources of organic and humic substances. These specific substances are applicable in industry, agriculture, the environment, and biomedicine with well-known and novel approaches. Analysis of the organic compounds fulvic acid, humic acid, and humin in different peat and sapropel extracts from Lithuania was performed in this study. The dominant organic compound was bis(tert-butyldimethylsilyl) carbonate, which varied from 6.90% to 25.68% in peat extracts. The highest mass fraction of malonic acid amide was in the sapropel extract; it varied from 12.44% to 26.84%. Significant amounts of acetohydroxamic, lactic, and glycolic acid derivatives were identified in peat and sapropel extracts. Comparing the two extraction methods, it was concluded that active maceration was more efficient than ultrasound extraction in yielding higher amounts of organic compounds. The highest amounts of fulvic acid (1%) and humic acid and humin (15.3%) were determined in pure brown peat samples. This research on humic substances is useful to characterize the peat of different origins, to develop possible aspects of standardization, and to describe potential of the chemical constituents.


2008 ◽  
Vol 68 (5-6) ◽  
pp. 415-419 ◽  
Author(s):  
Wan Aini Wan Ibrahim ◽  
Dadan Hermawan ◽  
Mohamed Noor Hasan ◽  
Hassan Y. Aboul Enein ◽  
M. Marsin Sanagi

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