Biomonitoring human exposure to organohalogenated substances by measuring urinary chlorophenols using a high-throughput screening (HTS) immunochemical method

The urinary level of 2,4,5-trichlorophenol was positively associated with both all-cause and cause-specific mortalities in general adult residents of United States

Chlorophenols are widespread environmental organic pollutants with harmful effects on human beings. Although relationships between chlorophenols and various dysfunctions/diseases have been reported, the contribution of chlorophenols exposure to mortalities is underdetermined. In this cohort study, we included 4 types of urinary chlorophenols, aiming to estimate associations of chlorophenols exposure with all-cause and cause-specific mortalities. Urinary chlorophenols were examined at baseline of National Health and Nutrition Examination Survey (NHANES) 2003-2010, and adjusted for the urinary creatinine level. Associations between chlorophenols and mortalities were estimated using COX regression analyses, results were shown as hazard ratio (HR) and 95% confidence interval (95% CI). By dividing participants into four subgroups based on quartiles of urinary levels of chlorophenols, associations between mortalities and categorical variables of chlorophenols were estimated. Furthermore, the quantile g-computation analysis was used to estimate the joint effects of 4 chlorophenols on mortalities. Among 5817 adults (2863 men), 1034 were deceased during the follow-up. After adjusted for confounders, 2,4,5-trichlorophenol (2,4,5-TCP) was found to be positively associated with both all-cause (HR = 1.46; 95% CI: 1.16, 1.84) and cardiovascular disease (CVD) mortalities (HR = 1.60; 95% CI: 1.00, 2.55). Compared to the subgroup of the lowest level of chlorophenols, participants in subgroups of higher 2,4,5-TCP levels showed higher risk of all-cause mortality (P-value for trend = 0.003). For CVD mortality, HRs in subgroups of higher levels of 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP) were statistically significant (P-values for trend were 0.017 for 2,4-DCP and 0.049 for 2,4,6-TCP). The HRs (95% CI) of joint effects of 4 chlorophenols were 1.11 (1.01, 1.21) and 1.32 (1.10, 1.57) for all-cause and CVD-specific mortalities, and 2,4,5-TCP showed the highest weight in joint effects. All of these findings implied that among 4 urinary chlorophenols we included, 2,4,5-TCP might be a sensitive one in associations with mortalities among general populations.

Sequential Intraoperative Evaluation of Rotational Stability of Cementless Stem in Total Hip Arthroplasty: A Broach-Based Study

In cementless total hip arthroplasty, the rotational stability of the stem is generally confirmed in a one-time manual evaluation by the surgeon. This study was performed to evaluate the sequential intraoperative changes in rotational stability using a torque wrench. Primary total hip arthroplasty was performed on 52 consecutive hips using a single wedge stem design. Intraoperative evaluation of rotational stability was uniformly performed using a torque wrench. Evaluations were performed immediately after broach insertion and immediately before the final insertion of the stem (after placement of the acetabular cup). Immediately after the insertion of the broach, rotational stability was checked and confirmed to be fully stabilized using a torque wrench in all cases, and the stability was maintained in 17 of 52 (33%) hips immediately before the final insertion of the stem. Among the hips showing instability, 11 of 35 (31%) broaches were upsized, while the remaining 24 hips achieved stabilization through deeper insertion of the broach. In conclusion, the rotational stability achieved immediately after the insertion of the broach was not necessarily maintained during surgery, indicating that rotational stability may need to be checked at multiple time points intraoperatively.

Association of bone mineral density with trichlorophenol: a population-based study

BACKGROUND

Trichlorophenols (TCPs) are metabolites of several organochlorine chemicals, including chlorobenzene, hexachlorocyclohexane, and chlorophenoxy acid, present in air, surface water, soil, and sediment. Many studies have shown that endocrine disruptors (EDs)may contribute to decreased bone mass and the increased risk of osteoporosis. However, the relationship between TCP and bone mineral density (BMD) has not been studied yet.

METHODS

We conducted a cross-sectional study by using data from the 2005-2010 National Health and Nutrition Examination Survey (NHANES). TCP levels were measured in urine samples from 3385 participants and bone mineral density was obtained by dual X-ray absorptiometry (DXA) lumbar spine and femur scanning. Multiple regression analysis, stratified analysis, curve fitting analysis, and trend tests were used to assess the relationship between TCP and BMD.

RESULT

After adjusting for confounding factors, the results of multiple regression analysis only showed that ln-2,4,5-TCP was negatively associated with BMD of lumbar spine. In stratified analyses, Male, Menstruating Female and Menopausal Female were divided into three groups for analysis. The results showed that ln-2,4,5-TCP and ln-2,4,6-TCP were not statistically associated with BMD in total femur, femoral neck, femoral tuberosity, intertrochanteric femur and lumbar spine, which was also confirmed by curve fitting analyses and trend tests.

CONCLUSION

This study demonstrated that 2,4,5-TCP and 2,4,6-TCP in urine samples were not significantly associated with BMD in the US population. Therefore, 2,4,5-TCP and 2,4,6-TCP may not be detrimental to BMD.

Parental and transgenerational impairments of thyroid endocrine system in zebrafish by 2,4,6-tribromophenol

Many environmental contaminants could be transmitted from parents and generate impairments to their progeny. The 2,4,6-tribromophenol (TBP), a novel brominated flame retardant which has been frequently detected in various organisms, was supposed to be bioaccumulated and intergenerational transmitted in human beings. Previous studies revealed that TBP could disrupt thyroid endocrine system in zebrafish larvae. However, there is no available data regarding the parental and transgenerational toxicity of this contaminant. Thus, in this study adult zebrafish were exposed to environmental contaminated levels of TBP for 60 days to investigate the parental and transgenerational impairments on thyroid endocrine system. Chemical analysis verified the bioaccumulation of TBP in tested organs of parents (concentration: liver>gonads>brain) and its transmission into eggs. For adults, increased thyroid hormones, disturbed transcriptions of related genes and histopathological changes in thyroid follicles indicate obvious thyroid endocrine disruptions. Transgenerational effects are indicated by the increased thyroid hormones both in eggs (maternal source) and in developed larvae (newly synthesized), as well as disrupted transcriptional profiles of key genes in HPT axis. The overall results suggest that the accumulated TBP could be transmitted from parent to offspring and generate thyroid endocrine disruptions in both generations.

Bioconcentration of 2,4,6-tribromophenol (TBP) and thyroid endocrine disruption in zebrafish larvae

2,4,6-tribromophenol (TBP) is generally used as a brominated flame retardant but is produced in the degradation of tetrabromobisphenol-A. Although TBP is frequently detected in the environment and in various biota, including fish species, we still know little about its toxicity and environmental health risk. Here we investigated the bioconcentration and effects of TBP on the thyroid endocrine system by using zebrafish as a model. Zebrafish embryos (2 h post-fertilization, hpf) were exposed to five concentrations of TBP (0, 0.3, 1, 10, and 100 μg/L) until 144 hpf. According to our chemical analysis, TBP underwent bioconcentration in zebrafish larvae. However, acute exposure to TBP did not affect the hatching of embryos or their risk of malformation, nor the growth and survival of larvae, indicating low developmental toxicity of TBP. The whole-body thyroxine (T4) contents were significantly increased in zebrafish larvae after exposure to TBP, indicating thyroid endocrine disruption occurred. Gene transcription levels in the hypothalamic-pituitary-thyroid (HPT) axis were also examined in larvae; these results revealed that the transcription of corticotrophin-releasing hormone (crh), thyrotropin-releasing hormone (trh), and thyroid-stimulating hormone (tshβ) were all significantly downregulated by exposure to TBP. Likewise, genes encoding thyronine deiodinases (dio1, dio2, and dio3a/b) and thyroid hormone receptors (trα and trβ) also had their transcription downregulated in zebrafish. Further, the gene transcription and protein expression of binding and transport protein transthyretin (TTR) were significantly increased after TBP exposure. Taken together, our results suggest the bioavailability of and potential thyroid endocrine disruption by TBP in fish.

Graphene Oxide-Crospolyvinylpyrrolidone Hybrid Microspheres for the Efficient Adsorption of 2,4,6-Trichlorophenol

Microspheres of the graphene oxide and crospolyvinylpyrrolidone composite (GO-PVPP) were prepared via suspension polymerization and investigated for the adsorption of 2,4,6-trichlorophenol (2,4,6-TCP) from wastewater. The microspheres were thoroughly characterized using scanning electron microscopy, infrared spectroscopy, N2 physisorption, elemental analysis, X-ray diffraction, and thermogravimetric analysis. The GO-PVPP microspheres comprised GO sheets on the surface and demonstrated good thermal stability, good swelling rate, and excellent adsorption capacity of 2,4,6-TCP (up to 466.77 mg/g). The adsorptions were determined as a function of pH, temperature, adsorbent loading, adsorption time, and initial content of 2,4,6-TCP in the solutions. The sorption kinetics was satisfactorily modeled using the pseudo-second-order rate equation, and the sorption equilibrium can be described using the Freundlich model. The 2,4,6-TCP adsorption by GO-PVPP was shown to be endothermic and spontaneous. The reusability of GO-PVPP was also demonstrated by the adsorption and desorption cycles.

Anthropometric measures at age 3 years in associations with prenatal and postnatal exposures to chlorophenols

BACKGROUND

Chlorophenols (CPs), suspected as endocrine disrupting chemicals, exposure during early life may contribute to body size. However, limited human data with inconsistent findings have examined the developmental effects of CPs exposure.

OBJECTIVE

To explore associations between prenatal and postnatal CPs exposure and anthropometric parameters in children aged 3 years.

METHODS

A subset of 377 mother-child pairs with urinary five CP concentrations were enrolled from a prospective birth cohort. Generalized linear models were conducted to evaluate associations of CPs exposure with children's anthropometric measures.

RESULTS

Maternal urinary 2,4,6-trichlorophenol (2,4,6-TCP) concentrations were significantly negatively associated with weight z scores [regression coefficient (β) = -0.51, 95% confidence interval (CI): -0.96, -0.05; p = 0.01], weight for height z scores (β = -0.54, 95% CI: -1.02, -0.06; p = 0.01) and body mass index (BMI) z scores (β = -0.53, 95% CI: -1.03, -0.03; p = 0.01) of children aged 3 years, after adjustment for potential confounders and postnatal CPs exposure. In the sex-stratified analyses, these inverse associations remained among boys, while in girls, positive associations of prenatal 2,4,6-TCP exposure with weight for height z scores and BMI z scores were observed. Postnatal exposure to 2,5-diclorophenol (2,5-DCP) was positively associated with weight z scores (β = 0.26, 95% CI: 0.02, 0.50; p = 0.04), after controlling for possible confounders and maternal CPs exposure during pregnancy. Considering potential sex-specific effects, these associations were only observed in girls.

CONCLUSIONS

Our findings indicate that prenatal 2,4,6-TCP exposure and postnatal 2,5-DCP exposure may have adverse and sex-specific effects on children's physical development.

Changes in the activities of antioxidant enzymes and reduced glutathione level in human erythrocytes exposed to selected brominated flame retardants

Currently, more and more concerns are related to oxidative stress appearing in cells as a result of xenobiotics action. It has been found that selected brominated flame retardants (BFRs) can cause reactive oxygen species (ROS) induction at environmental concentrations. Excessive ROS induction can contribute to the redox imbalance in the cell. Therefore, the aim of our work was to evaluate the effect of selected BFRs on the activity of antioxidant enzymes, i.e. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the level of reduced glutathione (GSH) in human erythrocytes. Erythrocytes were incubated with tetrabromobisphenol A (TBBPA), tetrabromobisphenol S (TBBPS), 2,4-dibromophenol (2,4-DBP), 2,4,6-tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) in the concentration ranging from 1 to 100 μg/ml. This study has shown that the BFRs studied disturbed redox balance in human erythrocytes. TBBPA caused more significant decrease in antioxidant enzymes activities than other compounds examined. Among bromophenols studied, 2,4-DBP most strongly affected antioxidant system, which indicated that the number of bromine atoms in the molecule did not significantly affect the pro-oxidative properties of the BFRs examined.

Applying bio-electric field of microbial fuel cell-upflow anaerobic sludge blanket reactor catalyzed blast furnace dusting ash for promoting anaerobic digestion

In this study, a novel manner of bio-electric field (BEF) which generated by upflow anaerobic sludge blanket (UASB)-microbial fuel cell (MFC) integrated system facilitated iron-carbon micro-electrolysis in blast furnace dusting ash (BFDA) was proposed for the reinforcement of anaerobic digestion in UASB. The responses of COD removal efficiency and biogas production with (0.1-0.4 V) BEF catalyzed 5 g BFDA(R_{MFC-5gBFDA-UASB}) were much higher than the other tests, and maximum reached 86% and 240 ml/d respectively. Ultra-fast acidogenesis was achieved with 0.3 V BEF supplied to BFDA and the time shortened 94 h compared controlled (R_UASB) with R_{MFC-5gBFDA-UASB}. With the electrochemical and microbial community analysis, the redox ability and direct interspecies electron transfer accumulated with BEF catalyzed. The abundance of Firmicutes which could generate bio-hydrogen was highest in R_{MFC-5gBFDA-UASB} (44.58%) compared to R_UASB (31.36%) and R_5gBFDA-UASB (40.04%). In addition, the structure and morphology variation of BFDA revealed that the synergistic effects of BEF stimulated iron-carbon micro-electrolysis for electron transferring and enhanced the activities of methanogens and acetogens with high relative abundance to biotransform organic compounds, as well as adsorption and precipitation of iron oxides (hematite and magnetite) promoting anaerobic digestion. The MFC-BFDA-UASB integrated system provides a promising and cost-effective way to enhance anaerobic digestion and recycled functionalized waste effectively.

In vitro assessment of eryptotic potential of tetrabromobisphenol A and other bromophenolic flame retardants

Brominated flame retardants (BFRs) such as tetrabromobisphenol A (TBBPA) and tetrabromobisphenol S (TBBPS) as well as bromophenols, i.e. 2,4-dibromophenol (2,4-DBP), 2,4,6-tribromophenol (2,4,6-TBP) and pentabromophenol (PBP) have raised wide concerns due to their widespread occurrence in the environment and adverse effects observed in living organisms including human. The effect of BFRs on apoptosis of human erythrocytes has not been examined, that is why we have decided to assess eryptotic potential of these substances by determining changes in phosphatidylserine (PS) translocation, alterations in intracellular ROS and calcium ion levels, as well as caspase-3 and calpain activation in this cell type. It has been found that all BFRs studied even in the concentration of 0.001 μg/mL induced ROS formation. The compounds examined caused apoptosis by PS externalization and caspase-3 activation in human red blood cells. It has also been shown that calcium ions and calpain did not play a significant role in eryptosis induction by BFRs studied in human erythrocytes.

Environmental concentrations and toxicology of 2,4,6-tribromophenol (TBP)

2,4,6-Tribromophenol is the most widely produced brominated phenol. In the present review, we summarize studies dealing with this substance from an environmental point of view. We cover concentrations in the abiotic and biotic environment including humans, toxicokinetics as well as toxicodynamics, and show gaps of the current knowledge about this chemical. 2,4,6-Tribomophenol occurs as an intermediate during the synthesis of brominated flame retardants and it similarly represents a degradation product of these substances. Moreover, it is used as a pesticide but also occurs as a natural product of some aquatic organisms. Due to its many sources, 2,4,6-tribromophenol is ubiquitously found in the environment. Nevertheless, not much is known about its toxicokinetics and toxicodynamics. It is also unclear which role the structural isomer 2,4,5-tribromophenol and several degradation products such as 2,4-dibromophenol play in the environment. Due to new flame retardants that enter the market and can degrade to 2,4,6-tribromophenol, this compound will remain relevant in future years - not only in aquatic matrices, but also in house dust and foodstuff, which are an important exposure route for humans.

Biomonitoring of chlorophenols in human urine from several Asian countries, Greece and the United States

Chlorophenols (CPs) are used in the production of pesticides and preservatives. Although human exposure to CPs has been known for years, current exposure levels to these chemicals in Asian countries are not known. In this study, we analyzed concentrations of eight CPs in 300 human urine samples collected from nine countries. Of these CPs, 2,5-dichlorophenol and 2,4-dichlorophenol were found at the highest median concentrations (median for all nine countries: 1.78 and 0.34 ng/mL, respectively). Pentachlorophenol was found in 59% of the samples analyzed at a median concentration of 0.07 ng/mL. Urine samples from Japan had the highest concentration of total CPs (median: 16.7 ng/mL) with 2,5-dichlorophenol accounting for 93.1% of the total concentration. The estimated daily intake (DI) for precursors of dichlorophenols varied widely, but several samples showed values higher than the acceptable DI recommended by the United States Environmental Protection Agency (EPA). These results suggest that CP exposure, especially to dichlorophenols, is prevalent in several countries, particularly in Asia, suggesting a pressing need for further assessment of the global sources and potential health effects of these chemicals.

Disulfide isomerase-like protein AtPDIL1-2 is a good candidate for trichlorophenol phytodetoxification

Trichlorophenol (TCP) is a widely used and persistent environmentally toxic compound that poses a carcinogenic risk to humans. Phytoremediation is a proficient cleanup technology for organic pollutants. In this study, we found that the disulfide isomerase-like protein AtPDIL1-2 in plants is a good candidate for enhancing 2,4,6-TCP phytoremediation. The expression of AtPDIL1-2 in Arabidopsis was induced by 2,4,6-TCP. The heterologously expressed AtPDIL1-2 in Escherichia coli exhibited both oxidase and isomerase activities as protein disulfide isomerase and improved bacteria tolerance to 2,4,6-TCP. Further research revealed that transgenic tobacco overexpressing AtPDIL1-2 was more tolerant to high concentrations of 2,4,6-TCP and removed the toxic compound at far greater rates than the control plants. To elucidate the mechanism of action of AtPDIL1-2, we investigated the chemical interaction of AtPDIL1-2 with 2,4,6-TCP for the first time. HPLC analysis implied that AtPDIL1-2 exerts a TCP-binding activity. A suitable configuration of AtPDIL1-2-TCP binding was obtained by molecular docking studies using the AutoDock program. It predicted that the TCP binding site is located in the b-b' domain of AtPDIL1-2 and that His254 of the protein is critical for the binding interaction. These findings imply that AtPDIL1-2 can be used for TCP detoxification by the way of overexpression in plants.

Molecularly Imprinted Nanofiber Film for Sensitive Sensing 2,4,6-Tribromophenol

The determination of brominated flame retardants is of great importance, but remains a challenge. Particularly, universal and facile approaches are limited. Here we report a new general approach, combining molecular imprinting and electrospinning, for the efficient and facile imprinting sensor of 2,4,6-tribromophenol (TBP), which was used as a “novel” brominated flame retardant. With TBP as the template molecular, β-cyclodextrin (β-CD) as the functional monomer, and poly-vinylbutyral (PVB) as the electro-spinning matrix, the nanofiber film was deposited on the glassy carbon electrode (GCE) via electrospinning technique directly. The β-CD-PVB/GCE sensor system exhibited excellent TBP sensing performances, such as a low detection limit (6.29 × 10⁻¹⁰ mol·L⁻¹) at room temperature, selective recognition to TBP/phenol/4-methyl-phenol, and good regeneration performance. The approach of fabricating a molecular imprinting nanofiber sensor may shed new light in the detection of other phenolic pollutants.

Urinary concentrations of trichlorophenols in the Korean adult population: results of the National Human Biomonitoring Survey 2009

Trichlorophenols such as 2,4,5-trichlorophenol (2, 4,5-TCP) and 2,4,6-trichlorophenol (2,4,6-TCP) are organochlorine compounds to which the general public can be exposed via contaminated food, water, and air. This study assessed exposure to 2,4,5-TCP and 2,4,6-TCP in Koreans age 18-69 years based on the Korean National Human Biomonitoring Survey conducted in 2009. Using data from 1,865 representative Koreans, we found that the geometric mean urinary concentrations of 2,4,5-TCP and 2,4,6-TCP were 83.4 pg/mL [95 % confidence interval (CI)=78.6-88.6] and 0.39 ng/mL (95 % CI=0.35-0.42), respectively. The creatinine-adjusted geometric mean 2,4,5-TCP and 2,4, 6-TCP levels were 78.8 ng/g creatinine (95 % CI=73.8-84.1) and 0.36 μg/g creatinine (95 % CI=0.33-0.40), respectively. Of the Korean adult population, about 67.5 and 87.5 % had respective urine 2,4,5-TCP and 2,4,6-TCP concentrations >0.05 ng/mL (the limit of detection, LOD). Urine 2,4,5-TCP concentrations were significantly associated with age and place of residence, whereas urine 2,4,6-TCP concentrations were higher in rural residents. These findings suggest that most Koreans had detectable levels of 2,4,5-TCP and 2,4,6-TCP in their urine and that the body burden of 2,4,5-TCP and 2,4,6-TCP varied according to demographic and geographic factors.

Urinary trichlorophenol levels and increased risk of attention deficit hyperactivity disorder among US school-aged children

Background

Trichlorophenols (TCPs) are organochlorine compounds which are ubiquitous in the environment and well known for their carcinogenic effects. However, little is known about their neurotoxicity in humans.

Objectives

Our goal was to examine the association between body burden of TCPs (ie, 2,4,5-TCP and 2,4,6-TCP) and attention deficit hyperactivity disorder (ADHD).

Methods

We calculated ORs and 95% CIs from logistic regression analyses using data from the 1999–2004 National Health and Nutrition Examination Survey (NHANES) to evaluate the association between urinary TCPs and parent-reported ADHD among 2546 children aged 6–15 years.

Results

Children with low levels (<3.58 μg/g) and high levels (≥3.58 μg/g) of urinary 2,4,6-TCP had a higher risk of parent-reported ADHD compared to children with levels below the limit of detection (OR 1.54, 95% CI 0.97 to 2.43 and OR 1.77, 95% CI 1.18 to 2.66, respectively; p for trend=0.006) after adjusting for covariates. No association was found between urinary 2,4,5-TCP and parent-reported ADHD.

Conclusion

Exposure to TCP may increase the risk of behavioural impairment in children. The potential neurotoxicity of these chemicals should be considered in public health efforts to reduce environmental exposures/contamination, especially in countries where organochlorine pesticides are still commonly used.

Chronic exposure to environmental levels of tribromophenol impairs zebrafish reproduction

Tribromophenol (2,4,6-TBP) is ubiquitously found in aquatic environments and biota. In this study, we exposed zebrafish embryos (F(0); 2"" days post-fertilization, dpf) to environmental concentration (0.3 microg/L) and a higher concentration (3.0 microg/L) of TBP and assessed the impact of chronic exposure (120 dpf) on reproduction. TBP exposure did not cause a significant increase in the malformation and reduction in the survival in the F(0)-generation fish. After TBP exposure, the plasma testosterone and estradiol levels significantly increased in males and decreased in females. The transcription of steroidogenic genes (3beta-HSD, 17beta-HSD, CYP17, CYP19A, CYP19B) was significantly upregulated in the brain and testes in males and downregulated in the brain and ovary in females. TBP exposure significantly downregulated and upregulated the expression of VTG in the liver of female and male fish, respectively. Meanwhile, TBP exposure altered the sex ratio toward a male-dominant state. The F(1)-generation larvae exhibited increased malformation, reduced survival, and retarded growth, suggesting that TBP in the aquatic environment has significant adverse effects on fish population.

Non-invasive matrices in human biomonitoring: a review

Humans and other living organisms are exposed to a variety of chemical pollutants that are released into the environment as a consequence of anthropogenic activities. Environmental pollutants are incorporated into the organism by different routes and can then be stored and distributed in different tissues, which leads to an internal concentration that can induce different alterations, adverse effects and/or diseases. Control measures should be taken to avoid these effects and human biomonitoring is a very useful tool that can contribute to this aim. Human biomonitoring uses different matrices to measure the target chemicals depending on the chemical, the amount of matrix necessary for the analysis and the detection limit (LOD) of the analytical technique. Blood is the ideal matrix for most chemicals due to its contact with the whole organism and its equilibrium with organs and tissues where chemicals are stored. However, it has an important disadvantage of being an invasive matrix. The development of new methodology and modern analytical techniques has allowed the use of other matrices that are less or non-invasive, such as saliva, urine, meconium, nails, hair, and semen or breast milk. The presence of a chemical in these matrices reflects an exposure, but correlations between levels in non-invasive matrices and blood must be established to ensure that these levels are related to the total body burden. The development of new biomarkers that are measurable in these matrices will improve non-invasive biomonitoring. This paper reviews studies that measure Cd, Pb, Hg, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and phthalates in non-invasive matrices, the most used techniques for measurements and what alternative techniques are available.

Phenolics: occurrence and immunochemical detection in environment and food

Phenolic compounds may be of natural or anthropogenic origin and be present in the environment as well as in food. They comprise a large and diverse group of compounds that may be either beneficial or harmful for consumers. In this review first a non-exhausting overview of interesting phenolics is given, in particular with regards to their presence in environment and food. For some of these compounds, beneficial, toxicological and/or optionally endocrine disrupting activities will be presented. Further, immunochemical detection and/or isolation methods developed will be discussed, including advantages and disadvantages thereof in comparison with conventional analytical methods such as HPLC, GC, MS. A short overview of new sensor-like methods will also be included for present and future application.

Immunochemical analysis of 2,4,6-tribromophenol for assessment of wood contamination

2,4,6-Tribromophenol (2,4,6-TBP) has been used as a wood preservative and flame retardant and is a synthetic intermediate of the most important brominated flame retardants (BFR) produced. The use of TBP-contaminated wood materials in the food industry poses a risk of significant economical losses due to food contamination. In this work an efficient and reliable immunochemical method for analysis of TBP in wood samples has been established consisting of alkaline wood extraction followed by analysis on a microplate ELISA (enzyme-linked immunosorbent assay). TBP is efficiently extracted from wood samples in 10 min and directly measured after 10-fold buffer dilution to avoid matrix interferences. The analytical procedure has a limit of detection of 45 ng g (-1) of TBP in wood (1.5 microg L (-1) in extracts). The method has been applied to the analysis of contaminated real wood samples, showing that the levels of contamination can reach high TBP concentrations (up to 2000 microg L (-1)). An excellent correlation was observed between TBP levels in wood extracts determined by ELISA and gas chromatography-mass spectrometry (GC-MS) analysis ( R (2) = 0.990, N = 19). The precision found is below 22% CV. The immunoanalytical method developed is fast, reliable, and cost-effective, shows good high-throughput screening capabilities, and can be an excellent tool for assessment of wood contamination at lumber mills or related industries. The TBP ELISA has the potential to be used for environmental, food, and biological monitoring of brominated phenolic compounds considered nowadays as emerging pollutants.

Determination of haloanisols in white wine by immunosorbent solid-phase extraction followed by enzyme-linked immunosorbent assay

A high through-put screening immunochemical method to control the presence of 2,4,6-trichloroanisol (TCA) and 2,4,6-tribromoanisol (TBA), the main agents responsible for the musty odor in wine samples, has been developed. The method involves a selective (antibody-antigen) solid-phase extraction (SPE), followed by enzyme-linked immunosorbent assay (ELISA) analysis. The sample preparation method established uses for immunosorbents (ISs) prepared by covalently coupling antibodies developed for TCA on a sepharose support. At present, about 200-400 ng L-1 of TBA and TCA can be detected in white wine samples by the IS-SPE-ELISA method described here without any preconcentration step. Simultaneous analyses of many samples are possible with this method. Related chloroanisoles (2,3- and 2,6-dichloroanisols and 2,3,4,5-tetrachloroanisol) and chlorophenols (2,3,4,6-tetrachlorophenol and pentachlorophenol) usually present in contaminated wine samples are also effectively retained by the IS, although only 2,4,6-TCA and 2,4,6-TBA are detected by the ELISA used. The immunopurification procedure developed could also be useful as a selective cleanup method prior to chromatographic analysis.