Nonylphenol Isomers Research Articles

Alkylphenols and Phthalates in Greywater from Showers and Washing Machines

Paris conurbation is a heavily urbanized but weakly industrialized catchment. Recently, it has been shown at the scale of Paris that alkylphenols (AP) and phthalates (PAE) are not rejected by the industry, but they originate from domestic wastewater at more than 95 %. However, the contribution of the different types of greywater to the pollution by alkylphenols and phthalates was not addressed. This work aims at providing new insights on this particular point. Hence, the concentration of four phthalates (diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), benzyl butyl phthalate (BBP), and di(2-ethylhexyl)phthalate (DEHP)) and two alkylphenols (octylphenols (OP) and isomers of nonylphenol (NP)) were followed in greywater. For each sample, analyses were carried out on both the dissolved and particulate phases. Moreover, water quality parameters were also monitored, in order to find out whether or not any correlation exists between the concentration of the investigated contaminants and the quality of water. Water quality parameters studied are pH, total suspended solids (TSS), dissolved and particular organic carbon (DOC and POC), chemical and biochemical oxygen demands (COD and BOD5), total Kjeldahl nitrogen (TKN), and anionic detergents (methylene blue active substance or MBAS). This paper presents the methodology used to monitor two greywater with the most important volumes: showers and washing machines. These greywater showed high variability with regard to water quality parameters. Moreover, AP and PAE concentrations are given for the first time for these two types of greywater. All compounds except OP were observed in almost all samples in at least one of the two monitored phases. The concentrations varied between limit of quantification for OP and 102 μg/l for DEHP. The levels measured in washing machines were higher than those for showers for all compounds. For instance, median NP concentration in washing machines was 3.59 μg/l against 1.09 μg/l in showers, DEHP was observed at 102 μg/l in washing machines against 16.6 μg/l in showers. Variability of the results was explained by habits of individuals (shower time, number of products used…) but also by differences in product composition. However, each type of water exhibited the same distribution. NP was the most abundant AP (about 85 % of the total amount) while DEHP represented the two thirds of the PAE compounds. The partition coefficients (Kd in l/kg) were evaluated. The results showed that log Kd ranged between 2.1 (DEP) and 4.8 (DEHP). Log Koc presented similar trends lying in the 2.4 (DEP)-5.0 (DEHP) range. Finally, with regard to greywater quality, the application for greywater reuse is discussed.

Determination of alkylphenols in water samples using liquid chromatography–tandem mass spectrometry after pre-column derivatization with dansyl chloride

The present study describes an effect of reaction condition of pre-column derivatization of alkylphenols (APs): bisphenol A (BPA), 4-tert-octylphenol (4-t-OP), 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), and isomers of 4-nonylphenol (iso-NP) with 5-(dimethylamino) naphthalene-1-sulfonyl chloride (dansyl chloride, DNSC) on their LC–ESI–MS/MS determination in water samples. Chemical derivatization improves the sensitivity and selectivity of LC–MS/MS analysis. In principle, alkylphenols can be analyzed by LC–MS/MS without derivatization. However, pre-column derivatization of APs increases the sensitivity up to 1000 times in comparison with the analysis of underivatized alkylphenols. Reaction conditions affecting formation of the DNSC-derivatives, such as various solvent, reaction temperature, reaction time, DNSC concentration and pH values were tested. The most suitable conditions, in terms of achieving a high sensitivity, resulting from this study are: acetonitrile as reaction solvent, 60min as reaction time, 60°C as reaction temperature, pH values 10.5, 0.5mgmL−1 as DNSC concentration. Calibration curves are linear at least in the range of 1–1000ngmL−1, limits of detection (LOD) and limits of quantification (LOQ) ranging from 0.02 to 0.25pg/injection and from 0.08 to 0.83pg/injection, respectively. The improved procedure was successfully applied for the analysis of APs and BPA in real water samples. The median concentration of BPA and iso-NP obtained in bottled waters was 4.7ngL−1 and 33.5ngL−1, respectively. The median concentration of 4-t-OP was 1.3ngL−1.

Effect of alkyl chain on the NLO property of nonylphenol isomers: a DFT study

Density functional theory (DFT) method was employed to study the nonlinear optical (NLO) response of the nonylphenol isomers with different alkyl substituents (methyl, ethyl, propyl, and isopropyl). The linear alkyl chain (hyperpolarizability, β T) and alkyl group aggregation (Hyper Rayleigh scattering hyperpolarizability, β HRS) in nonylphenol isomer has a strong positive influence on the NLO property. Among all the substituents, the methyl dominated alkyl chain nonylphenol isomers are strong NLO materials due to their large polarizability and hyperpolarizability values compared to that of urea/phenol. The absorption spectra obtained from TD-DFT study suggest that the absorption bands are shifted towards the UV–Vis region, dominated by π–π* transitions. The C–H···π intramolecular interactions are a blue shift in nature; however, their function and influence on the NLO property is insignificant. The Rayleigh scattering is dominant for methyl and ethyl substituent, while in the Rayleigh activity is controlled by the natural light.

Analysis of phenolic compounds in the dissolved and suspended phases of Lake Balaton water by gas chromatography-tandem mass spectrometry

As a novel approach to characterize the phenolic pollutants of Lake Balaton (Central Europe, western Hungary), 26 endocrine disrupting phenols (chlorophenols, nitrophenols, alkylphenols, triclosan, bisphenol-A) were quantified in dissolved and suspended particulate matter (SPM) phases, alike. Sample collection was performed in the western and eastern basins, at 20 sites in April and October 2014. Solid-phase and ultrasound-assisted extractions to withdraw target phenols from dissolved and suspended phases were employed. Compounds were derivatized with hexamethyldisilazane and trifluoroacetic acid for their quantification as trimethylsilyl derivatives by gas chromatography-tandem mass spectrometry. In Lake Balaton's dissolved phase, 2-chlorophenol (103-164 ng/L), 4-chlorophenol (407-888 ng/L), 2,4-dichlorophenol (20.2-72.0 ng/L), 2,4,6-trichlorophenol (10.4-38.1 ng/L), 2-nitrophenol (31.0-66.5 ng/L), 4-nitrophenol (31.5-94.1 ng/L), and bisphenol-A (20.6-112 ng/L), while in its SPM, 4-chlorophenol (<LOQ-1274 μg/kg, dry matter), 4-nitrophenol (423-714 μg/kg), 4-nonylphenol isomers (1500-2910 μg/kg), and bisphenol-A (250-587 μg/kg) were determined. Since phenolics appear partially or exclusively in the SPM, the analysis of both phases proved to be of primary importance. Graphical Abstract ᅟ.

Spatial distribution and migration of nonylphenol in groundwater following long-term wastewater irrigation

Seen as a solution to water shortages, wastewater reuse for crop irrigation does however poses a risk owing to the potential release of organic contaminants into soil and water. The frequency of detection (FOD), concentration, and migration of nonylphenol (NP) isomers in reclaimed water (FODRW), surface water (FODSW), and groundwater (FODGW) were investigated in a long-term wastewater irrigation area in Beijing. The FODRW, FODSW and FODGW of any or all of 12 NP isomers were 66.7% to 100%, 76.9% to 100% and 13.3% to 60%, respectively. The mean (±standard deviation) NP concentrations of the reclaimed water, surface water, and groundwater (NPRW, NPSW, NPGW, repectively) were 469.4±73.4ngL−1, 694.6±248.7ng−1 and 244.4±230.8ng−1, respectively. The existence of external pollution sources during water transmission and distribution resulted in NPSW exceeding NPRW. NP distribution in groundwater was related to the duration and quantity of wastewater irrigation, the sources of aquifer recharge, and was seen to decrease with increasing aquifer depth. Higher riverside infiltration rate nearby leads to higher FODGW values. The migration rate of NP isomers was classified as high, moderate or low.

Isomer-specific biodegradation of nonylphenol in an activated sludge bioreactor and structure–biodegradability relationship

Nonylphenol (NP), one of the priority hazardous substances, is in fact a mixture of numerous isomers. It is inconclusive whether or not biodegradation during wastewater treatment process is isomer-specific, leading to the environmental release of NP in different isomer profiles. In this study, we evaluated the isomer selectivity of 19 NP isomers in a laboratory-scale continuous flow conventional activated sludge bioreactor under various operational conditions. The removal efficiency of NP isomers ranged from 90 to 99%, depending on the operational conditions and isomer structures. Isomer selective biodegradation resulted in the increase of composition of recalcitrant isomers, such as, NP193a/b, NP110a and NP194 in the effluent. Moreover, biodegradability was related to the bulkiness of α-substituents and followed α-dimethyl > α-ethyl-α-methyl > α-methyl-α-n-propyl > α-iso-propyl-α-methyl. Steric effect index, a quantitative descriptor of steric hindrance, was linearly correlated with residues of NP isomers in the effluent (R2 = 0.76). Decrease of temperature to 10 °C decreased the overall biodegradability and also enhanced the relative enrichment of recalcitrant isomers. These findings suggest that isomer compositions of NP entering the environment may be different from those in technical mixtures and that isomeric selectivity should be taken into account to better understand the occurrence, fate, and ecological risks of NP.

Effects of 4-nonylphenol isomers on cell receptors and mitogen-activated protein kinase pathway in mouse Sertoli TM4 cells.

In the present study, experiments were performed to investigate the effects of nonylphenol (NP) isomers (4-[1,2, 4-trimethylhexyl]-phenol (NP41), 4-[1,2, 5-trimethylhexyl]-phenol (NP42)) on Sertoli TM4 cells. NP41 decreased mRNA expression levels of androgen receptor and toll-like receptor (TLR)-4 in 20-40μM (P<0.05), and increased mRNA levels of estrogen receptor (ER)-α and progesterone receptor in 1-40μM (P<0.05). NP42 treatment only evoked significant decrease in mRNA expression levels of ER-α in 20-40μM (P<0.05). Similarly, NP41 (1-40μM) drastically increased the protein expression of ER-α, which was significantly decreased in 20-40μM NP42 groups (P<0.01). Both NP41 and NP42 showed no effect on the expression of ER-β. Protein levels of follicle stimulating hormone receptor were increased significantly in high concentrations of NP41 (40μM) and NP42 (10-40μM) challenged cells. Furthermore, NP41 and NP42 showed various effects on the expression of junction-associated molecules and inhibin B secretion in TM4 cells. Additionally, activation of JNK1/2 pathway was induced by NP41 and NP42. However, ERK1/2 and p38 pathways were inhibited in TM4 cells exposed to low concentrations of NP41 (0.1-20μM) and NP42 (0.1-1μM), and high concentrations of NP41 (40μM) and NP42 (10-40μM) resulted in a return of p-ERK1/2 and p-p38 to control levels. We proposed that molecular mechanism of reproductive damage in Sertoli cells induced by NPs may be mediated by cell receptors and/or cell signaling pathways, and the effects may be related to the structure of NP isomer.

Isomer-specific oxidation of nonylphenol by potassium permanganate

Nonylphenol (NP), the metabolite of non-ionic surfactant nonylphenol ethoxylates, is a well-known environmental endocrine disruptor. Nonylphenol is frequently detected in treated wastewater effluent, impacted surface water and even in drinking water due to its heavy use. Nonylphenol has been treated as a single compound in most studies to date, but in reality it is a mixture of numerous isomers. Recent studies showed that different NP isomers displayed different estrogenicity and biodegradability in the environment. In this study, we examined, for the first time, the potential isomeric selectivity in the oxidation of NP. The reaction kinetics of 19 NP isomers, including 6 diastereoisomers, with potassium permanganate was measured at pH 5, 7 and 9. At pH 7 with 10mgL−1 of KMnO4 and 50μgL−1 technical mixture of NP, the half-lives of 19 isomers varied from 4.8 to 6.3min. In general, the reaction followed the order: α-dimethyl>α-ethylmethyl≈α-methylpropyl≈α-iso-propylmethyl. The oxidation rate of NP isomers with KMnO4 increased with increasing pH and a greater dependence on pH was observed for isomers with α-dimethyl substituents. This study suggested that α-substituents may be the dominant factor regulating the reactivity and persistence of NP isomers during advanced oxidation processes.

Isomer-Specific Biodegradation of Nonylphenol in River Sediments and Structure-Biodegradability Relationship

Nonylphenol (NP), a well-known environmental estrogen with numerous isomers, is frequently found in surface water and sediments. Recent studies showed that NP isomers exhibited different estrogenicity. However, at present little information is available on its isomer-specific degradation in the bed sediment, which is the primary sink of NP in surface aquatic systems. In this study, we investigated the biodegradability of 19 NP isomers in two river sediments under oxic and anoxic conditions. Under oxic conditions, the half-lives of NP isomers in an upper river sediment ranged from 0.9 to 13.2 d. Under reduced conditions, the persistence of NP isomers generally increased, with negligible dissipation under strongly reduced conditions. In the well-aerated sediment, NP isomers with short side chain and/or bulky α-substituents were found to be more recalcitrant to degradation. Moreover, when a total of 57 molecular descriptors were examined, the degree of branching as quantified by IDWbar was found to result in the best linear correlation with half-lives of NP isomers (R(2) = 0.88). These results indicated that the isomer-specificity of NP in environmental processes should be considered, and that simple molecular descriptors may be used to identify the more recalcitrant isomers, thus allowing prioritization in the evaluation of environmental fate and risks of NP isomers.

Incorporation Mechanisms of a Branched Nonylphenol Isomer in Soil-Derived Organo–Clay Complexes during a 180-Day Experiment

The incorporation process of a defined (13)C- and (14)C-labeled nonylphenol isomer (4-(3,5-dimethylhept-3-yl)phenol) into soil-derived organo-clay complexes was investigated. Isolated organo-clay complexes were separated into humic subfractions. Noninvasive ((13)C-CP/MAS NMR) and invasive methods (sequential chemical degradation, pyrolysis) were applied to obtain detailed information about the mode of incorporation, chemical structure, and change of the incorporation character of nonextractable residues in course of incubation. (13)C-CP/MAS NMR measurements of humic acids revealed an increasing incorporation of phenolic compounds during the experimental time which was referred to residues of the introduced (13)C-labeled NP isomer. Detailed investigations by means of sequential chemical degradation indicated a predominant incorporation of nonextractable NP isomer residues via reversible ester (amide) bonds. In course of time, the amount of releasable compounds decreased, pointing to altering processes which affected the mode of incorporation. BBr3-treatment, RuO4 oxidation, and thermochemolysis released only low portions of nonextractable radioactivity giving evidence of strongly incorporated residues. With the comprehensive application of complementary methods (e.g., humic matter fractionation, (13)C-CP/MAS NMR, sequential chemical degradation) it was possible to provide a comparatively detailed insight into the incorporation behavior of the applied NP isomer.

Sifat Anti Cendawan Trichophyton mentagrophytes dan Candida albicans dari Zat Ekstraktif Kayu Pelanjau (Pentaspadon motleyi)

Trichophyton mentagrophytes and Candida albicans Antifungal Activity of Palanjau (Pentaspadon metleyi) Wood ExtractivesPelanjau wood (P. motleyi) extractives traditionally used as medicine for skin infection such as scabies (tinea) and rash caused by fungal T. mentagrophytes and C. albicans. The aim of this research was to identify the effectiveness of pelanjau wood extractives on growth inhibitory of fungal T. mentagrophytes and C. albicans, isolate and identify extract compounds which have antifungal properties. Extraction and fractionation process yielded 7,04% of ethanol extract consisting of 0,28%, 1,28%, 1,19% and 4,29% of n-hexane, diethyl ether, ethyl acetate and residue fractions, respectively. Antifungal activity of pelanjau wood extract more effective on C. albicans growth inhibition than T. mentagrophytes fraction ethyl acetate at (0,03 and 0,06 mg/ml of MIC and MFC, respectively). Isolation of ethyl acetate fraction was resulted dominant compound EA6a and EA6c. NMR and GC MS analysis of compound EA6a indicate 2-Hidroxy octadecanoid acid, Hexadecanoic acid, Ethyl oleate, Octadecanoic acid, Vanilin and phenol,2-methoxy-4-(1-propenyl) as the possibly main component belonged to fatty acid and phenol group. Compound EA6c indicate Phenol, 4-(1,1 dimetylpropyl), Nonylphenol isomer, Phenol,4-(1,1,2,2-tetrametylbutyl), Nonyl-phenol mix isomer dan 4-Nonylphenol as the possibly main component in belong to phenol group.

Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

A characterization of activated carbon (ACs) prepared from rice husks (RHs) under base treated condition as a new sorbent for solid-phase extraction (SPE) to extract 4-nonylphenol isomers (4-NPs) in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance interaction of non-polar sorbent with analyte in the water matrices. In this case, silanol groups from ash content may affect the extraction efficiency for 4-NPs. The ACs made from RHs were chemically impregnated with ZnCl 2 and carbonized at 800 o C. To investigate the role of silica, three types of ACs were prepared, i.e., untreated ACs (AC–Si, contain silica), base treated ACs (AC–B–Si, remain some silica inside), and ACs made by base treated RHs (AC–B, no silica), the surface area obtained from these treatments were 1352 m 2 /g, 1666 m 2 /g, and 1712m 2 /g respectively. ACs made by base treatment has the highest surface area (related to BET), which indicat that silica removal process promotes the formation of open pore system on ACs and enhances the surface area of ACs. However, extraction efficiency measured by GC-MS in SPE process showed the reversal trends (i.e., AC–Si= 32.08%, AC–B–Si= 82.63%, AC–B=51.78%), among them the AC–B–Si sorbent reveal the best performance in SPE process. It is indicated that although silica usually exhibits low specific surface area, but control presence of silica as a polar functional group has a positive influence in the interaction between non-polar sorbent and 4-NPs.

Estrogenic activity and effects on biotransformation of nonylphenol and octylphenol isomers in liver cells of Atlantic salmon (Salmo salar) in vitro

Estrogenic activity and effects on biotransformation of nonylphenol and octylphenol isomers in liver cells of Atlantic salmon (Salmo salar) in vitro

Rapid determination of alkylphenols in aqueous samples by in situ acetylation and microwave‐assisted headspace solid‐phase microextraction coupled with gas chromatography–mass spectrometry

A rapid and solvent-free procedure for the determination of 4-tert-octylphenol and 4-nonylphenol isomers in aqueous samples is described. The method involves in-situ acetylation and microwave-assisted headspace solid-phase microextraction prior to their determination using gas chromatography-ion trap mass spectrometry operated in the selected ion storage mode. The dual experimental protocols to evaluate the effects of various derivatization and extraction parameters were investigated and the conditions optimized. Under optimized conditions, 300 μL of acetic anhydride mixed with 1 g of potassium hydrogencarbonate and 2 g of sodium chloride in a 20 mL aqueous sample were efficiently extracted by a 65 μm polydimethylsiloxane-divinylbenzene fiber that was located in the headspace when the system was microwave irradiated at 80 W for 5 min. The limits of quantitation were 5 and 50 ng/L for 4-tert-octylphenol and 4-nonylphenol isomers, respectively. The precision for these analytes, as indicated by relative standard deviations, were less than 8% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 74 to 88%. A standard addition method was used to quantitate 4-tert-octylphenol and 4-nonylphenol isomers, and the concentrations ranged from 120 to 930 ng/L in various environmental water samples.

Comparative evaluation of nonylphenol isomers on steroidogenesis of rat Leydig Cells

Nonylphenol (NP) has been proven to be one of the most investigated xenohormones interacting with the estrogen receptor. Technical nonylphenol (t-NP) contains at least 20 para-substituted isomers. It has been shown that NP isomers vary in their estrogenic potency. So the use of mixtures or impure substances can lead to misinterpretations and unsatisfying conclusions. In the present study, experiments were performed to examine effects of NP isomers on steroidogenesis of rat Leydig cells. Primary cultured Leydig cells were exposed to NP isomers (p33-NP, p262-NP, p353-NP, p363-NP) at the optimized inhibitory concentration 5μmol/L for 6h. NP isomers showed various degrees of inhibition of testosterone biosynthesis, with p363-NP leading to the most significant decrease and others sharing the similar efficacy. The expression of 3b-HSD, Cyp11a1, Star and the apoptosis of Leydig cells were further measured to investigate the underlying mechanisms. We demonstrated that NP isomers can affect the steroidogenesis of rat Leydig cells, at least in part, through their influence on gene expression and cell apoptosis, but varied in their individual degree. However, the final results were not completely coincident with their estrogenic potency tested in vitro, which implies that effects of NP isomers on steroidogenesis appear to be mediated through some other underlying mechanisms besides their various estrogenic potency.

Formation of Toxic 2-Nonyl-p-Benzoquinones from α-Tertiary 4-Nonylphenol Isomers during Microbial Metabolism of Technical Nonylphenol

In many environmental compartments, microbial degradation of α-quaternary nonylphenols proceeds along an ipso-substitution pathway. It has been reported that technical nonylphenol contains, besides α-quaternary nonylphenols, minor amounts of various α-H, α-methyl substituted tertiary isomers. Here, we show that potentially toxic metabolites of such minor components are formed during ipso-degradation of technical nonylphenol by Sphingobium xenophagum Bayram, a strain isolated from activated sewage sludge. Small but significant amounts of nonylphenols were converted to the corresponding nonylhydroquinones, which in the presence of air oxygen oxidized to the corresponding nonyl-p-benzoquinones-yielding a complex mixture of potentially toxic metabolites. Through reduction with ascorbic acid and subsequent analysis by gas chromatography-mass spectrometry, we were able to characterize this unique metabolic fingerprint and to show that its components originated for the most part from α-tertiary nonylphenol isomers. Furthermore, our results indicate that the metabolites mixture also contained several α, β-dehydrogenated derivatives of nonyl-p-benzoquinones that originated by hydroxylation induced rearrangement, and subsequent ring and side chain oxidation from α-tertiary nonylphenol isomers. We predict that in nonylphenol polluted natural systems, in which microbial ipso-degradation is prominent, 2-alkylquinone metabolites will be produced and will contribute to the overall toxicity of the remaining material.

Two identical nonylphenol monooxygenase genes linked to IS6100 and some putative insertion sequence elements in Sphingomonas sp. NP5

Sphingomonas sp. NP5 can degrade a wide range of nonylphenol (NP) isomers that have widely contaminated aquatic environments as major endocrine-disrupting chemicals. To understand the biochemical and genetic backgrounds of NP degradation, a gene library of strain NP5 was constructed using a broad-host-range vector pBBR1MCS-2 and introduced into Sphingobium japonicum UT26. Several transformants accumulated reddish brown metabolites on agar plates dispersed with a mixture of NP isomers. Two different DNA fragments (7.6 and 9.3 kb) involved in the phenotype were isolated from the transformants. Sequence analysis revealed that both fragments contained an identical 1593 bp monooxygenase gene (nmoA), the predicted protein sequence of which showed 83 % identity to the octylphenol-4-monooxygenase of Sphingomonas sp. PWE1. The nmoA gene in the 7.6 kb fragment was surrounded by an IS21-type insertion sequence (IS) and IS6100, while another in the 9.3 kb fragment was adjacent to an IS66-type IS, suggesting that they have been acquired through multiple transposition events. A fast-growing recombinant Pseudomonas putida strain harbouring nmoA was constructed and used for degradation of a chemically synthesized NP isomer, 4-(1-ethyl-1-methylhexyl)phenol. This strain converted the isomer into hydroquinone stoichiometrically. 3-Methyl-3-octanol, probably originating from the alkyl side chain, was also detected as the metabolite. These results indicate that these two nmoA genes are involved in the NP degradation ability of strain NP5.

Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry

4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid–liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC×GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment.

Problems and improvements of the regulated analyses method on GC for nonyl phenol isomers

We report problems and improvements of a regulated analytical GC method supported by ISO/DIS 24293 for nonyl phenol isomers (NPs). The variations of peak area and recovery of NPs were found on a regulated GC method which 4-n-nonyl phenol-2,3,5,6-d4 (4-np-d) and phenanthrene-d10 (fnt-d) were utilized as surrogate compounds with syringe spiking. Furthermore, we investigated the relative recovery by the continuous injection of NPs, 4-np-d, and fnt-d, then the decrease rate of peak area of each compound was different although all peaks were gradually decreased. Consequently, the decrease rates of NPs and 4-np-d were higher, and the relative recovery of NPs were also decreased. After cutting off the GC column (about 50 cm) and replacement of an injection insert, the peak areas of compounds were completely recovered. Therefore, we anticipate that the problem was caused by adsorption or degradation of NPs in the inlet area. Additionally, a similar decrease of peak area was observed on the pretreated real samples by the effect of matrix.

Sorption of a branched nonylphenol and perfluorooctanoic acid on Yangtze River sediments and their model components

Many metabolites of organic surfactants such as nonylphenol (NP) and perfluorooctanoic acid (PFOA) are ubiquitously found in the environment and are toxic if not sorbed on soils and sediments. In this study, we quantified the sorption of the NP isomer with the highest endocrine activity, [4-(1-ethyl-1,3-dimethylpentyl) phenol] (NP111), and that of PFOA on Yangtze River sediments and its model components illite, goethite and natural organic matter. The sorption experiments were performed with (14)C-labeled NP111 and PFOA by batch or dialysis techniques. The results showed that the sorption isotherms of NP111 and PFOA on the sediments were fitted well by the linear adsorption model. The sorption of NP111 depended largely on the organic carbon content of the sediments. The K(OC) values of NP111 ranged from 6 × 10(3) to 1.1 × 10(4) L kg(-1) indicating that hydrophobic interaction between NP and organic carbon is the main mechanism of sorption. The sorption of NP111 on illite was poor. The sorption of PFOA on the sediments was significantly lower than that of NP111. The affinity of PFOA to adsorb on goethite was slightly higher than on the sediments, but was moderate on illite and negligible on a reference natural organic matter. Principal axis component analysis confirmed that various sediment parameters control the binding of PFOA. This analysis grouped the respective K(d) values to the contents of black carbon, iron oxides and clay, and, hence, to the specific surface area of the sediments.