Wastewater-based epidemiology to assess human exposure to personal care and household products – A review of biomarkers,analytical methods,and applications

Humans are nowadays exposed to numerous chemicals in our day-to-day life, including parabens, UV filters, phosphorous flame retardants/plasticizers, bisphenols, phthalates and alternative plasticizers, which can have different adverse effects to human health. Estimating human’s exposure to these potentially harmful substances is, therefore, of paramount importance. Human biomonitoring (HBM) is the existing approach to assess exposure to environmental contaminants, which relies on the analysis of specific human biomarkers (parent compounds and/or their metabolic products) in biological matrices from individuals. The main drawback is its implementation, which involves complex cohort studies. A novel approach, wastewater-based epidemiology (WBE), involves estimating exposure from the analysis of biomarkers in sewage (a pooled urine and feces sample of an entire population). One of the key challenges of WBE is the selection of biomarkers which are specific to human metabolism, excreted in sufficient amounts, and stable in sewage. So far, literature data on potential biomarkers for estimating exposure to these chemicals are scattered over numerous pharmacokinetic and HBM studies. Hence, this review provides a list of potential biomarkers of exposure to more than 30 widely used chemicals and report on their urinary excretion rates. Furthermore, the potential and challenges of WBE in this particular field is discussed through the review of pioneer WBE studies, which for the first time explored applicability of this novel approach to assess human exposure to environmental contaminants. In the future, WBE could be potentially applied as an “early warning system”, which could promptly identify communities with the highest exposure to environmental contaminants.     

气相色谱-串联质谱法同时测定锂离子电池电解液中13种有机磷阻燃剂的含量

建立了一种可同时测定锂离子电池电解液中13种有机磷阻燃剂含量的气相色谱-串联质谱分析方法,以乙酸乙酯为萃取溶剂,超声萃取锂离子电池电解液中的有机磷阻燃剂,萃取液经浓缩、定容、过滤后进行气相色谱-串联质谱分析,外标法定量。结果显示,13种有机磷阻燃剂在一定浓度范围内线性良好,相关系数不低于0.999 3,方法的检出限(S/N=3)为0.3~30μg/kg,定量下限(S/N=10)为1~100μg/kg。在低、中、高3个加标水平下的平均回收率为80.4%~94.6%,相对标准偏差(RSD)为3.8%~10%。该方法简单快捷,灵敏度高,定量下限低,可满足锂离子电池电解液中有机磷阻燃剂含量日常检测需要。     

Organophosphate hydrolase — an enzyme catalyzing degradation of phosphorus-containing toxins and pesticides

The available investigations on the structure and properties of the enzyme organophosphate hydrolase exhibiting catalytic activity with respect to orthophosphates are reviewed. Recent data on the mechanism of enzymatic hydrolysis of paraoxon are surveyed. The role of two metal ions involved in the enzyme active site is considered. The substrate specificity and the influence of various inhibitors on the kinetic characteristics of the enzyme are discussed.     

Thermal and Surface Analytical Study of Flame Retarded Polyolefins I. Interaction of Additives and Structure Formation

Pentaerythritol may react with tetraethoxy-silane and ammonium-polyphosphate in flame retarded polyolefins and an interfacial layer can be formed around the ammonium-polyphosphate particles. It is advantageous to study such systems using methods of thermal and surface analysis together. This revised version was published online in August 2006 with corrections to the Cover Date.     

Pressurised hot-water extraction of brominated flame retardants in sediment samples

Summary A pressurised, hot-water extraction (PHWE) method was developed for brominated flame-retardants in sediments. The effect of extraction time, temperature and pressure on PHWE recovery was investigated, together with solid-phase collection parameters (trapping material, length of trapping column, eluent composition). The concentrated extracts were analysed by GC-MS. PHWE recoveries were compared with those obtained by conventional Soxhlet-extraction. In general, recoveries were much higher with PHWE than with Soxhlet.     

Preparation and combustion properties of flame retarded polypropylene-polyamide-6 alloys

In this work, polypropylene (PP) and polyamide-6 (PA6) alloys were prepared by blending PP and PA6 or nano-PA6 while using a compatibiliser such as maleic anhydride-g-polypropylene (MAPP). Their physical structures were characterized by Hitachi X650 scanning electron microscope (SEM) and transmission electron microscopy (TEM). An intumescent flame retardant (IFR) was added to the PP/PA6 alloys and their flammability behaviour was evaluated using cone calorimeter and real time Fourier transform infrared (FTIR). The probable mechanisms are discussed.     

Molecularly Imprinted Electrochemical Sensor for the Detection of Organophosphorus Pesticide Profenofos

The presence of profenofos (PFF) in food has been strictly limited by legislation due to its genotoxic and toxic effects on health. It is therefore very important to establish simple and rapid analytical methods to detect traces of this insecticide. A reusable molecularly imprinted polypyrrole MIP(O-PPy) on a glassy carbon electrode (GCE) has been developed to measure PFF. The PPy was polymerized by cyclic voltammetry (CV) in the presence of template molecules (PFF) in an acidic solution on a GCE. The various experimental parameters such as film thickness, analyte/monomer ratio, and removal/rebinding requirements were examined and optimized. The signal of the redox probe (ferrocyanide/ferrocyanide) was used for the electrochemical detections. All steps of the sensor manufacturing, removal/rebinding of template molecules, and response to different PFF concentrations were tested by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The MIP sensor was able to detect PFF in the linear ranges of 1.0×10⁻⁹ to 1.0×10⁻⁶ M and 1.0×10⁻⁹ to 5.0×10⁻⁶ M, with detection limits, a signal-to-noise ratio (S/N) of three was used to estimate LOD, of about 1 nM using DPV and EIS, respectively. The MIP (PPy) GCE provided excellent PFF recognition performance and was successfully used to quantify PFF in sweet pepper samples, yielding recoveries not greater than 108 %.     

New star‐shaped phosphorus‐containing flame retardants based on acrylates for epoxy resins

New star‐shaped phosphorus‐containing flame retardants were synthesized by phospha‐Michael‐addition of diphenylphosphine oxide and dimethyl phosphite to oligofunctional acrylates. The products were examined via UL 94 V‐rating and thermogravimetric analysis in three different epoxy resin systems compared to the recently described correspondent derivatives based on the phosphinate‐type 6‐oxido‐6H‐dibenzo[c,e][1,2]oxaphosphinine. The influence of a systematically altered chemical environment of the phosphorus atom on the flame retardancy and the char yield was investigated. Furthermore, the glass transition temperatures of the modified resins were studied via differential scanning calorimetry, including the deviation after an additional treatment at elevated temperature. Copyright © 2013 John Wiley & Sons, Ltd.     

Multi-class,multi-residue analysis of pesticides,polychlorinated biphenyls,polycyclic aromatic hydrocarbons,polybrominated diphenyl ethers and novel flame retardants in fish using fast,low-pressure gas chromatography–tandem mass spectrometry

A multi-class, multi-residue method for the analysis of 13 novel flame retardants, 18 representative pesticides, 14 polychlorinated biphenyl (PCB) congeners, 16 polycyclic aromatic hydrocarbons (PAHs), and 7 polybrominated diphenyl ether (PBDE) congeners in catfish muscle was developed and evaluated using fast low pressure gas chromatography triple quadrupole tandem mass spectrometry (LP-GC/MS–MS). The method was based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction with acetonitrile and dispersive solid-phase extraction (d-SPE) clean-up with zirconium-based sorbent prior to LP-GC/MS–MS analysis. The developed method was evaluated at 4 spiking levels and further validated by analysis of NIST Standard Reference Materials (SRMs) 1974B and 1947. Sample preparation for a batch of 10 homogenized samples took about 1 h/analyst, and LP-GC/MS–MS analysis provided fast separation of multiple analytes within 9 min achieving high throughput. With the use of isotopically labeled internal standards, recoveries of all but one analyte were between 70 and 120% with relative standard deviations less than 20% (n = 5). The measured values for both SRMs agreed with certified/reference values (72–119% accuracy) for the majority of analytes. The detection limits were 0.1–0.5 ng g⁻¹ for PCBs, 0.5–10 ng g⁻¹ for PBDEs, 0.5–5 ng g⁻¹ for select pesticides and PAHs and 1–10 ng g⁻¹ for flame retardants. The developed method was successfully applied for analysis of catfish samples from the market.     

Application of polydimethylsiloxane rod extraction to the determination of sixteen halogenated flame retardants in water samples

An extraction and preconcentration procedure for the determination in water samples of several halogenated flame retardants (FRs), nine brominated diphenyls ethers (BDEs) and seven non-BDE FRs, was developed and validated. The optimised procedure is based on polydimethylsiloxane (PDMS) rods as sorptive extraction material, followed by liquid desorption and gas chromatography coupled to negative chemical ionisation–mass spectrometry (GC–NCI–MS) determination, rendering an efficient and inexpensive method. The final optimised protocol consists of overnight extraction of 100 mL of sample solutions containing 40% MeOH and 4% NaCl, followed by a 15-min sonication-assisted desorption with 300 μL of ethyl acetate, solvent evaporation and GC–NCI–MS analysis. Under these conditions, extraction efficiencies in the 9 to 70% range were obtained, leading to enrichment factors between 108 and 840, detection limits in the range from 0.4 to 10 ng L⁻¹and RSD values in the 2–23% range. After method validation, different real water samples, including river, ria, sea, landfill leachate, influent and effluent wastewater from an urban sewage treatment plant (STP) and effluent wastewater from a textile industry, were analysed. BDE-47, BDE-99, BDE-100 and BDE-197 were detected in wastewater and landfill leachate samples at concentration levels up to 2887 ng L⁻¹. Among the non-BDE FRs, bis (2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (DEHTBP) was detected in surface water samples (sea, river and ria) between 1.3 and 2.2 ng L⁻¹ and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in the landfill leachate (64 ng L⁻¹).