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A method was developed for the determination of 10 organic acids in liquor, yellow rice wine, and dry red wine by ion chromatography-triple quadrupole mass spectrometry (IC-MS/MS). First, the liquor samples were diluted with deionized water, degassed with nitrogen, and analyzed by IC-MS/MS. Then, the yellow rice wine and dry red wine samples were purified with different solid-phase extraction cartridges. Finally, the GCB solid-phase extraction cartridge was selected for purification, diluted with deionized water, and analyzed by IC-MS/MS. The samples were separated using a Dionex IonPac AS11-HC anion analysis column with high capacity and strong hydrophilicity, with an KOH aqueous solution as the eluent, which was produced by an automatic generator for gradient elution. After being suppressed using a suppressor, the eluent was injected directly into the electrospray ionization tandem mass spectrometry (ESI-MS/MS), ionized in negative ion mode, detected in multiple reaction monitoring (MRM) mode, and quantified using an external standard method. Oxalic acid, fumaric acid, maleic acid, malic acid, tartaric acid, citric acid, quinic acid, and aconitic acid showed good linear relationships in the range of 0.05-2 mg/L. Succinic acid and lactic acid showed good linearities in the range of 0.05-5 mg/L and 0.05-10 mg/L, respectively. The correlation coefficients (

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a major storage pest that could lead to a wide range of damage. Its secretions have a significant impact on the quality of stored grain and food, leading to serious food safety problems such as grain spoilage and food carcinogenesis. This study investigates new detection techniques for grain storage pests to improve grain insect detection in China. The primary volatile organic chemicals (VOCs) in these secretions are identified using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The specific VOCs that are unique to T. castaneum are selected as criteria for determining the presence of T. castaneum in the granary. To obtain more specific VOCs, experiments were designed for the analysis of T. castaneum samples under different extraction times, two types of SPME fibers and two GC-MS devices of different manufacturers. The experimental results showed that 12 VOCs were detected at relatively high levels, seven of which were common and which were not detected in other grains and grain insects. The seven compounds are 1-pentadecene, 2-methyl-p-benzoquinone, 2-ethyl-p-benzoquinone, 1-hexadecene, cis-9-tetradecen-1-ol, m-cresol and paeonol. These seven compounds can be used as volatile markers to identify the presence of T. castaneum, which could serve as a research foundation for the creation of new techniques for T. castaneum monitoring.

Polyhalogenated carbazoles (PHCZs), are considered as potential persistent organic pollutants (POPs), which have been frequently detected in the environment. However, the altitudinal distribution characteristics and possible sources of PHCZs in high mountain soils are still unknown. The present study was the first to analyze PHCZs in soil samples collected along the eastern slope of Mt. Qionglai (MQ), the east edge of the Tibetan Plateau. The concentration of ΣPHCZs (based on dry weight) ranges from 14.4 to 107 ng/g (median value of 40.9), which was at high end of the range reported in soils and sediments to date in the literature. The composition profiles of PHCZs in the soils of MQ were dominated by 3,6-dichlorocarbazole (36-CCZ), 3-chlorocarbazole (3-CCZ), and 2-bromocarbazole (2-BCZ). The mean TOC-normalized concentrations of ΣPHCZs in soil samples from below-treeline (2092 ng/g TOC) were higher than those from alpine meadow (1124 ng/g TOC), probably due to the forest filter effect. The decreasing trend of the PHCZs TOC-normalized concentrations with altitude shows that accumulation of PHCZs from the alpine meadow samples was not affected by the mountain cold-trapping effect. Significantly positive correlations were observed between the concentrations of more than half of detected PHCZ congeners and TOC. In addition, PHCZs show the potential to represent a class of POPs with the frequent occurrence and wide distribution, as the abundance and environmental behavior of PHCZs are similar to some POPs in MQ.

Organochlorine pesticides (OCPs), chemicals frequently used in agriculture, are a group of highly toxic and persistent organic pollutants. This study assesses the distribution and congener profiles of residual OCPs in 11 types of vegetable oils collected from Chinese markets. All samples were extracted using the modified QuEChERS method prior to analysis by gas chromatography-triple quadrupole mass spectrometry. The sesame oil samples had the highest concentration of OCPs, within the range of 15.30-59.38 ng/g, whereas the peanut oil samples had the lowest OCP concentrations, within the range of 10.83-35.65 ng/g. The possible effect of the processing technology on the pesticide residues in these vegetable oils was also evaluated. It was found that the pressing method leaves more OCPs in vegetable oils than the aqueous extraction and cold-pressing, but the result for leaching was not obvious. In light of the obtained results, it was estimated that the average daily intake of different pesticides is between 0.01 and 2.20 ng/kg bw/day for urban and rural households. Hence, it can be affirmed that, given the amount of the concentration of OCPs detected in the vegetable oils collected from Chinese markets, there are no obvious health risks for urban and rural households by intake.

Strawberries are highly popular around the world because of their juicy flesh and unique taste. However, they are delicate and extremely susceptible to peroxidation of their membrane lipids during storage, which induces water loss and rotting of the fruit. This study investigated the effects of ozone treatment on the physiological traits, active oxygen metabolism, and the antioxidant properties of postharvest strawberry. The results revealed that the weight loss (WL) and respiration rate (RR) of strawberry were inhibited by ozone treatment (OT), while the decline of firmness (FIR) and total soluble solids (TSS) were delayed. Ozone also reduced the generation rate of superoxide radical anions , and the content of hydrogen peroxide (H2O2) enhanced the activity of superoxidase (SOD), catalase (CAT), ascorbate peroxidase (APX), and monodehydroascorbate reductase (MDHAR), as well as promoted the accumulation of ascorbic acid (ASA), glutathione (GSH), and ferric reducing/antioxidant power (FRAP). In addition, a total of 29 antioxidant-related proteins were changed between the OT group and control (CK) group as detected by label-free proteomics during the storage time, and the abundance associated with ASA–GSH cycle was higher in the OT group at the later stage of storage, and the qRT-PCR results were consistent with those of proteomics. The improvement of the antioxidant capacity of postharvest strawberry treated with ozone may be achieved by enhancing the activity of the antioxidant enzymes and increasing the expression of the antioxidant proteins related to the ascorbic acid–glutathione (ASA–GSH) cycle.

Chlorinated paraffins (CPs) are organic pollutants that have caused widespread concerns in recent years. Because of their lipophilic characteristics, CPs may enter into the body through diet or other routes and exert adverse effects on human health. In this study, we investigated the occurrence and congener profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in 176 cooking oils and 19 oil containers collected from various markets in China. The concentrations of SCCPs and MCCPs in cooking oils were in the range of not detected (ND) to 16,055 ng/g and ND to 11,612 ng/g, respectively, and the geomean concentrations of MCCPs were lower than those of SCCPs. The concentrations of CPs in sesame oil, rapeseed oil, and camellia oil were higher than those in other types of oils, and different oil processing methods had different effects on the presence of CPs in the oils. CPs were detected in 5 out of 20 oil containers, although their concentrations were much lower than those detected in the oil samples, indicating that containers are not the main sources of CPs detected in the oils. The mean SCCP and MCCP intakes through cooking oils of the general Chinese population were 8.83 and 6.09 μg/kg/d, respectively.

Mineral oil hydrocarbon (MOH) contamination of various foods in the past few decades has raised much concern due to its potential adverse health effects. Since infant formulas (IF) is the major food source for infants, it is necessary to understand MOH contamination level in IF and consequent potential food safety risks. Data on the contamination of IF by mineral oil are lacking in China. On the other hand, the analysis of MOH in food is difficult. There is no harmonised standard analytical method for testing MOHs in IF. GC-FID/MS was chosen as the analytical tool being more convenient for surveys at a national level. Fifty-one IFs comprising dairy milk-based IFs (n = 39) and goat milk-based IFs (n = 12), including different stages (Stage 1, 2 and 3), package type (metal cans and paper boxes) were collected in China market in 2018 for this survey. 17 of 51 IFs were found positive, but trace levels MOAH were found (≤0.7 mg/kg). For the positive samples, all the MOSH and MOAH hump fell into the C16-C25 fraction. MOH humps were found in all the 12 goat milk-based IFs, even 4 samples are reported with quantifiable values which are higher than the method defined LOQ. The highest quantifiable MOH contamination level of goat milk-based IFs were MOSH = 3.5 mg/kg and MOAH = 0.7 mg/kg. Further root cause analysis of contamination is highly recommended to control the MOH contamination for goat milk-based IFs.

Biogenic amines (BAs), a class of nitrogenous compounds that are frequently detected in wine, pose adverse effects to humans. However, with the largest red wine consumption in the world, little is known about national profiles correlating BAs in wines to toxicological/health risks in China. In this study, we conducted a nationwide survey of commercially available wines for the occurrence of BAs. Our sampling campaign covered >90% of wine brands (n = 456) in China in a three year span (2014–2016). The target BAs included tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. In order to quantitatively characterize the potential risk and/or support regulatory decision-making, chronic and acute BA exposure scenarios were developed and simulated with a physiologically based pharmacokinetic model. The model described the fate and transport of BAs within human body using physical descriptions of relevant processes. These results provided baseline data that are needed for the risk assessment of dietary uptake of BAs and evaluating winemaking processes by food safety authorities.

The levels and distribution of tris-(2,3-dibromopropyl) isocyanurate (TBC) and hexabromocyclododecanes (HBCDs) in sediments in the intertidal zone of the New River Estuary were investigated. The concentration of TBC ranged from 2.78 to 35.1 ng·g−1dw, and the concentration of total HBCDs ranged from 10.3 to 43.5 ng·g−1dw. The composition of the three HBCD isomers, α-, β-, and γ-HBCD, was 6.23%, 8.00% and 85.8%, respectively. Moreover, the mass inventory of TBC, α-, β-, γ-HBCD, and total HBCDs in sediments were estimated to be about 1465.49, 124.64, 154.98, 1707.54, 1987.16 kg, respectively. Compared to previous studies, the concentrations of TBC and HBCDs in the intertidal zone of the New River Estuary were relatively high. Therefore, more concern of the potential public health and environmental risks of TBC and HBCDs is necessary.

Polyhalogenated carbazoles (PHCZs) have been detected in various environments frequently and have attracted increasing attention for their multiple toxicities. However, only a few reports record the occurrence of PHCZs in farmland soils, and the sources of which were not yet been implemented. In this study, 12 PHCZs and carbazole (CZ) were screened in farmland soil samples from the Three Northeast Provinces, and the ∑PHCZs were in the range of 18.16-219.67 ng/g dw. 36-CCZ was the dominant congener (40.67%) in farmland soils, followed by 3-CCZ (14.51%), and average percentages of other congeners were lower than 10%. A concrete analysis of the sources of PHCZs in the soil was conducted, revealing the diversity of PHCZs sources. Potential toxic effects associated with the levels of PHCZs were evaluated via the toxic equivalency (TEQ) approach, and the TEQs of PHCZs (TEQPHCZs) were in the range of 2.24-14.06 pg TEQ/g dw. Notwithstanding the 1368-CCZ with a low concentration level, the mean contribution to TEQPHCZs was up to 24.24%, preceded only by 36-CCZ (39.69%), showing the congeners with low concentration also may pose potential risks to the environment. Partial PHCZs congeners (2-BCZ, 3-BCZ, 36-CCZ, 136-BCZ, and 2367-BCZ) showed significant correlations (r = 0.45-0.63, p < 0.05) with the total organic carbon (TOC). Significant correlations were shown between PHCZ congeners replaced by halogens of the same species and quantity (r = 0.40-0.99, p < 0.01). In view of the fact that the high concentration level of PHCZs in the soil and their source diversity, more environmental monitoring and risk assessments of PHCZs should be of particular concern.

An increasing number of organic compounds are manufactured, consumed, and discarded every year. Incomplete destruction of these compounds in wastewater treatment plants leads to pollution of natural waters, posing great health and ecological concerns. Ultrasound, as an emerging advanced oxidation technology, can quickly and effectively degrade organic pollutants in waters. To improve removal efficiency of organic pollutants in an ultrasonic system, operational parameters, especially pH, have been frequently evaluated and optimized. This review show that pH-induced changes in volatility, hydrophobicity and Coulombic force between the target compound and cavitation bubbles leads to higher degradation at acidic pH for most compounds. In addition, pH also changes free radical formation and reactivity in water during sonication, thereby altering degradation kinetics of target compounds. However, the influence of pH is not always consistent for various organic pollutants covering a broad range of physicochemical properties and reactivities. A systematic investigation on the pH effect is necessary to elucidate how pH alters cavitation bubble dynamics and collapse, radical yield and reactivity, distribution of target compounds in the vicinity of cavitation bubbles, water matrices transformation, and ultimately the degradation kinetics of organic pollutants. This first systematic review provides valuable insight into the pH effects on organic pollutant sonolysis, helps to improve our mechanistic understanding of the sonochemical system, and sheds light on future application of ultrasound in water engineering.

In recent years, microplastics in oceans have become a serious environmental problem and the focus of attention. In the present study, the sorption of TBC and HBCDs by microplastics in simulated seawater is examined. The effects of particle size, temperature, salinity, and concentration on the adsorption of TBC and HBCDs by microplastics are studied. Results indicate that the first-order adsorption kinetic model is more suitable than the pseudo-second-order kinetic model to describe adsorption. The equilibrium adsorption times are 15 h and 10 h for TBC and HBCDs, respectively. The adsorption capacity increases with the decrease in particle size. The adsorption capacity gradually increases at first and then decreases with the increase in salinity and temperature. The maximum adsorption capacity is at 15 °C and 14% salinity. Compared with the linear and Freundlich models, the Langmuir model is more suitable; this indicates that the main adsorption mechanism might be chemical adsorption.

The levels and distribution of tris-(2,3-dibromopropyl) isocyanurate (TBC) and hexabromocyclododecanes (HBCDs) of surface sediments in the Yellow River Delta wetland had been investigated. The concentrations of TBC and ∑ HBCDs ranged from 0.20 to 29.03 ng·g − 1 dw and below limits of detections (LODs) to 20.25 ng·g − 1 dw. The average composition profile of three HBCDs isomers were 10.1%, 6.1% and 83.8% for α-, β- and γ-HBCD, respectively. Moreover, correlation analysis indicated there are similar sources among three isomers and positive correlations between total organic carbon (TOC) content and concentrations of TBC and HBCDs. The mass inventory of TBC,α-, β-, γ-HBCD, ΣHBCDs in surface sediments of Yellow River Delta wetland were estimated about 725.50, 72.76, 44.29, 548.34, 665.39 kg. Therefore, further investigations on potential human health and environmental risk assessments of TBC and HBCDs were needed.

Japanese medakas (Oryzias latipes) and triolein-embedded cellulose acetate membranes (TECAMs) were exposed simultaneously to benzo[k]fluoranthene (BkF) in the static exposure system containing different concentrations of humic acid (HA). The concentration-response relationships of induced hepatic 7-ethoxysorufin-o-deethylase (EROD) activity were established in regard to the nominal water concentration of BkF and the free concentration estimated using TECAM, as well as the body residues, respectively. In general, bioaccumulation of BkF and EROD activity in medaka were reduced with an increase of HA concentration in the exposure medium. The concentration-response relationships varied with HA concentration when expressed in nominal concentration. However, these relationships overlapped completely and partially when expressed in body BkF residue and in free BkF concentration estimated by TECAM, respectively. HA treatments were slightly beyond the 0.95 confidence band of HA-free control thereby indicating the participation of BkF-HA complex to the bioavailability and toxicity. On the basis of the bioavailability model, it was estimated that approximately 17-22% and 13-18% of BkF-HA complex contributed to the bioaccumulation and/or to the induced toxic effect, correspondingly.

A new passive sampling device (PSD), a triolein-embedded cellulose acetate membrane (TECAM), was used to biomimetically accumulate naphthalene, phenanthrene, pyrene and benzo[a]pyrene from ten spiked soils and a soil spiked with different concentrations of these polycyclic aromatic hydrocarbons (PAHs). TECAM exposure conditions were optimized. The quantities of PAHs accumulated by TECAMs were positively and linearly related to their concentrations in the soil. PAHs accumulated by TECAMs were negatively related to soil organic matter (SOM) and positively related to the dissolved organic carbon (DOC) according to the results obtained from ten spiked soils. Aging time (1-150 days) had a significant effect on accumulation of PAHs by TECAMs. A good linear relationship (R-2 = 0.970-0.993) was observed between TECAM-accumulated PAHs and PAHs accumulated by earthworms (Eisenia andrei). The data indicate that TECAM represents a useful surrogate to estimate the bioavailability of PAHs and perhaps other hydrophobic organic contaminants (HOCs) in soils. (c) 2007 Elsevier Ltd. All rights reserved.

Dissolved organic carbon (DOC) is known to reduce the bioavailability of hydrophobic organic compounds (HOCs) in aqueous environments. This reduction occurs as a result of adsorption to DOC, apparently reducing the freely dissolved concentration of HOCs. In the present study, triolein-embedded cellulose acetate membrane (TECAM) and Japanese medaka (Oryzias latipes) were used to measure the uptake of acenaphthene and chrysene in the presence of commercial humic acid (HA) at different concentrations (0–15 mg C·L−1) under controlled laboratory conditions. Apparent uptake rate constants for PAHs in TECAM and medaka were compared and DOC-water partition coefficients (K DOCs) of two PAHs were calculated with different sampling methods by model fit. Results showed that HA present in water significantly reduced the uptake of PAHs in TECAM and medaka. The obtained values of log K DOC of acenaphthene and chrysene measured by TECAM were 4.63 and 5.83, respectively, whereas biologically determined values were 4.52 and 5.76, respectively. These log K DOC values were comparable to earlier published K DOCs toward commercial HA, thereby indicating that TECAM accumulated only the freely dissolved fraction of chemicals and uptake PAHs in a manner similar to that of fish. All these results suggested that the TECAM method can provide a good means for assessing the impact of DOC on bioavailability of PAHs in the aqueous environment.

Meiliang Bay is a sublake of Taihu Lake and has been polluted by domestic and industrial effluents. As part of a comprehensive risk assessment project in this region, semipermeable membrane devices (SPMDs) were applied to evaluate the levels and potential toxic potency of polycyclic aromatic hydrocarbons (PAHs) in lakewater, in combination with chemical analysis and in vitro bioassay using H4IIE rat hepatoma cells. In addition, induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity, in crucian carp (Carassius auratus), caged in the vicinity of SPMD sampling sites was also used as a biomarker of exposure to PAHs and related chemicals. The caged crucian carp accumulated similar PAH profile patterns (p

Uptake of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides-(OCPs) by triolein-containing semipermeable membrane devices (SPMDs) and by crucian carp (Carassius carassius) was studied in Taihu Lake, a shallow, freshwater lake in China. Crucian carp and SPMDs were deployed side by side for 32 d. The first-order uptake rate constants of individual PAHs and OCPs for the, two matrices were calculated and compared to relate the amounts of chemicals accumulated by the matrices to dissolved water concentrations. On a wet-weight basis, total concentrations of PAHs and OCPs in crucian carp fillets averaged 49.5 and 13.6 ng/g, respectively, after the 32-d exposure, whereas concentrations in whole SPMDs averaged 716.9 and 62.3 ng/g, respectively. The uptake rate constants of PAHs and OCPs by SPMDs averaged seven- and fivefold higher, respectively, than those for crucian carp; however, the patterns of uptake rate constants derived from test chemical concentrations in the crucian carp and SPMDs were similar. Although equilibrium was not reached for some PAHs and OCPs during the 32-d exposure period, a reasonably good correlation between the concentration factors (CFs) and octanol/water partition coefficient (K-OW) values of PAHs and OCPs in SPMDs (r = 0.86, p < 0.001) was observed when potential sorption to dissolved organic carbon was taken into account. Similar efforts to correlate the CFs and K-OW values of PAHs and OCPs in crucian carp (r = 0.75, p < 0.001) were less successful, likely because of PAH metabolism by finfish. Overall, the present results suggest that SPMDs may serve as a surrogate for contaminant monitoring with fish in freshwater lake environments.

A novel method is described using triolein-embedded cellulose acetate membrane (TECAM) for accurate determination of the freely dissolved fraction of organochlorine pesticides (OCPs) in waters rich in dissolved organic matter (DOM). The performance of the method was tested with an air-bridge system for extracting OCPs from aqueous solutions with and without humic acid. In addition, the partition coefficients between humic acid and water (K (doc)s) for 20 OCPs were determined by TECAM with negligible depletion extraction. Results show that TECAM predominantly extracts the freely dissolved compounds and its extraction efficiency decreases significantly with an increase in concentration of humic acid in water. The proposed methodology is suitable for facile laboratory K (doc) measurement for moderate to high hydrophobic compounds (log K (ow)4). The linear relationship between log K (ow) and log K (doc) obtained in this study agrees well with the results reported earlier. The kinetic uptake rate constants (k (u)s) and TECAM-water partition coefficients (K (TECAM)s) for the 20 OCPs were obtained using the controlled laboratory continuous-flow and static exposure system, respectively. These calibration parameters were used in the field experiment to estimate the freely dissolved concentrations of OCPs in the water of Taihu Lake in China. Our results show that TECAM can be used successfully to determine the freely dissolved OCPs in aquatic environments containing DOM, and the method is particularly suited for long-term water sampling. Figure Schematic diagram of water sampling with a triolein-embedded cellulose acetate membrane (TECAM).

In this paper we report an extension of our previous work on the triolein-embedded cellulose acetate membrane ( TECAM) as a passive sampling device ( PSD) and describe the results from simultaneous exposure of TECAMs and triolein-containing semipermeable membrane devices ( SPMDs) to PAHs in lake water for 16 days. The data obtained provided a comparison of the uptake rates of specific PAHs by the two PSDs. Using 16-day accumulation tests, similar PAH distribution patterns in TECAMs and in SPMDs ( R 2) 0.89, p < 0.0001) were observed. However, it was noted that TECAMs could take up greater amounts of PAHs than SPMDs ( 735 ng/g of TECAM vs 630 ng/g of SPMD). Uptake rate constants of TECAMs and SPMDs for 16 priority pollutant ( PP) PAHs, corrected for dissolved organic carbon, ranged from 0.28 to 2.94 L d(-1) and from 0.16 to 0.91 L d(-1), respectively. The elimination rate constants of TECAMs were 1.4-6.7 times greater than those observed for SPMDs, thereby indicating that PAHs required shorter times to achieve equilibrium in TECAMs than in SPMDs. Thus, the results of the present study suggest that TECAMs have significant potential as a good monitor to assess the pollution of hydrophobic pollutants in aquatic environments.

An ultra performance liquid chromatography-electrospray ionization tandem mass spectrometric (UPLC-ESI-MS/MS) method was established for the direct determination of ethyl carbamate in Chinese rice wine and grape wine. The Chinese rice wine and grape wine samples were diluted with distilled water, filtered through 0. 22 microm microporous membrane. The LC separation was performed on a Waters Acquity UPLC system with a BEH C18 column, acetonitrile and 0. 1% (v/v) acetic acid aqueous solution as the mobile phase. The ethyl carbamate was determined in the mode of electrospray positive ionization (ESI+) and multiple reaction monitoring (MRM). The butyl carbamate (BC) was used as the internal standard for the quantitative determination. The calibration curve showed good linearity in the range of 2 - 500 microg/L with the correlation coefficient greater than 0.995. The limit of detection (LOD) was 1.7 microg/L and the limit of quantification (LOQ) was 5.0 microg/L. The recoveries of the ethyl carbamate in Chinese rice wine and grape wine was in the range of 90% - 102%. The relative standard deviations (RSDs) of intra-day and inter-day determinations were 0. 8% - 4.5% and 1.4% - 5.6% (n = 6). The results indicated that the proposed method is easy, fast, sensitive, and suitable for the determination of ethyl carbamate in Chinese rice wine and grape wine.

Adsorption to dissolved organic matter (DOM) may significantly decrease the freely dissolved concentration of many hydrophobic organic compounds and, hence, result in reduced bioavailability to aquatic organisms. Here, the suitability of using triolein-embedded cellulose acetate membrane (TECAM) as a biomimetic surrogate to assess the bioavailability of organochlorine pesticides (OCPs) in water in the presence of DOM was explored. The accumulation of OCPs was measured in TECAM and pelagic Japanese medaka (Oryzias latipes) in the laboratory after 12 h exposure to water containing different levels of Aldrich humic acid. Further, OCP uptake by TECAM and medaka in real aqueous environments was evaluated after 30 d exposures in two sites. Laboratory results showed that OCP uptake by medaka consistently decreased with increasing levels of humic acid in the range of 0-15 mg C/L in sample solutions. This tendency was closely mimicked by OCP accumulation in TECAM under the same conditions. Field results showed that TECAM accumulated similar OCP patterns as medaka (r2 = 0.92 for site 1 and r2 = 0.94 for site 2), although comparison of the in-field eight OCP concentrations in TECAM to those in medaka yielded approximately a factor of 3 (on a wet weight basis). These results suggest that the TECAM method can be used as a simple and useful tool to predict the bioavailability and bioaccumulation potential of poorly biotransformed organic compounds in pelagic fish in aqueous environment.

A new type of composite membrane, triolein embedded cellulose acetate membrane (TECAM), was produced by embedding triolein drops in the matrix of cellulose acetate polymers. The distribution of six organochlorine pesticides (OCPs) between water and TECAM was investigated in a static water system. Its field application was tested in Taihu Lake (China). Results from both laboratory and field experiments indicate that TECAM quickly and efficiently accumulated hydrophobic OCPs from water. Under laboratory conditions, uptake equilibrium was achieved within 24 h for all of the six OCPs. Significant correlations were obtained between log Kp TECAM (TECAM-water partition coefficient) and log Kow (octanol-water partition coefficient); between log Ktw (triolein-water partition coefficient, triolein in TECAM) and log Kow; and between log Ktw and log BCF (bioconcentration factor in rainbow trout calculated from literatures). Triolein in TECAM significantly increased the accumulation of strongly hydrophobic OCPs when compared to the use of cellulose acetate polymers alone. Temperature had only slight effects on the Kp TECAM values of the strongly hydrophobic OCPs. The partition coefficient obtained by measuring OCP concentrations in TECAM under field conditions could be successfully applied to estimate OCPs concentrations in surface water.