Tri-iso-butyl Phosphate Research Articles

Appropriate Removal of Forest Litter is Beneficial to Pinus tabuliformis Carr. Regeneration in a Pine and Oak Mixed Forest in the Qinling Mountains, China

Research Highlights: Natural regeneration is important in pine–oak mixed forests (Pinus armandii Franch., Pinus tabuliformis Carr., and Quercus aliena Bl. var. acuteserrata Maxim.ex Wenz.), but allelopathy as a limiting factor has not been studied. Our research provides insights into allelopathy in pine–oak mixed forest litter. Background and Objectives: Allelopathy among tree species occupying the same ecological niche in mixed forests may adversely affect regeneration. We studied allelopathy in pine and oak forest litter to determine the effect on regeneration, whether it is offset by adding activated carbon or plant ash, and what allelopathic substances are present. Materials and Methods: We used laboratory seed culture and field seeding to determine pine and oak litter regeneration effects on P. tabuliformis and P. armandii in the Qinling Mountains, China. In the laboratory, we irrigated seeds with three different litter concentrations. A fourth treatment incorporated activated carbon. The field study established small quadrats in mixed forest to study how removing or retaining litter and spreading plant ash affected sown seeds. High performance liquid chromatography–mass spectrometry was used to compare differences in chemical substances in extracts with and without activated carbon. Results: Litter extracts significantly affected germination rates in both species. Seedling morphological and physiological indexes showed that litter extracts negatively affected growth in both species, but activated carbon alleviated this inhibitory effect on P. armandii. Forest stand and litter did not affect P. armandii seed germination. Pinus tabuliformis germination rates were significantly higher in plots with removed litter than when litter was retained or plant ash spread, and lower in oak than pine forest. Allelopathic substances detected in pine forest were trioctyl trimellitate, amyloid β-Peptide 10–20, and triisobutyl phosphate, potentially affecting P. armandii seed germination and growth. Conclusions: Appropriate removal of litter in mixed forests can improve the natural regeneration ability of P. tabuliformis.

Organic phosphorus compounds as heat release regulators in hardening shielding concrete

Abstract The paper presents the results of the study of the influence of the addition of retarding superplasticising admixture based on triisobutyl phosphate and modified phosphonates on the amount of heat generated by hardening shielding concrete. A four-point measurement of the heat generated during the hardening of concrete with an admixture dose of 0, 0.5, 1.0 and 2.0% by weight of the cement was made and the concurrent measurement of the heat released by the hardening cement paste was measured with an isothermal calorimeter. Based on the results from the calorimeter, the effect of the admixture on the temperature field in the hardening concrete mass elements was simulated for different aggregates. The results indicate that the admixture clearly lowers the temperature gradient in hardening mass concrete. In the simulations, the most clear effect was achieved in the case of concrete with barite aggregate, where the gradient value was reduced from 10°C/m to 8°C/m for an admixture content equal to 2.0%.

Recovery of lithium from underground brine by multistage centrifugal extraction using tri-isobutyl phosphate

The recovery of lithium from brine is a focus of worldwide due to the increasing demand of lithium in modern energy industry. Multistage centrifugal extraction was used in this work to recover lithium from underground brine. It was found that the centrifugal extraction rate of lithium is low by conventional methods, during which a multimolecular reaction with slow equilibrium time is involved. This problem was successfully solved by using an extraction system containing 80% tri-isobutyl phosphate (TIBP) and 20% sulfonated kerosene in combination with a novel operating method. The recycling of co-extractant (Fe3+) which is one of the bottleneck problems to limit the application of solvent extraction was also solved based on an innovative technical process. The recovery rate of lithium in underground brine reached to 90.05% by five-stage centrifugal extraction at optimized conditions. The stripping rate of lithium in organic phase was almost 100% using a solution containing 1.0 mol/L HCl at R(O/A) = 2:1. Lithium was not only separated from brine but also fourfold concentrated without any washing of the organic phase. This developed method is simple and thus is promising to be applied for the industrialized recovery of lithium from underground brine.

Levels, distribution, and sources of organophosphate flame retardants and plasticizers in urban soils of Shenyang, China.

Seventy-four soil samples from the road greenbelts, residential areas, drylands, waste grasslands, education lands, industrial areas, city parks, and rural homesteads of Shenyang city, China, were collected and analyzed for 13 organophosphate esters (OPEs). OPEs were detected in all analyzed soil samples, which indicate that OPEs are ubiquitously environmental contaminants. The ∑13OPEs concentrations ranged from 0.039 to 0.95mg/kg dry weight (dw), with the mean and median concentrations of 0.23 and 0.16mg/kg dw, respectively. The pollution levels of OPEs in different land use types were different; the concentrations of OPEs in dryland soils were maximum and in city park soils were minimum. Of 13 OPEs, tri-iso-butyl phosphate (TiBP), tris-(1-chloro-2-propyl) phosphate (TCPP), tri-butoxyethyl phosphate (TBEP), and tris[2-chloro-1-(chloromethyl) ethyl] phosphate (TDCP) were the most abundant OPEs, contributing 42.0 ± 12.8, 12.4 ± 2.32, 6.31 ± 1.88, and 5.76 ± 1.86% of ∑13OPEs, respectively. Principal component analysis (PCA) and absolute principal component score-multiple linear regression (APCS-MLR) suggested that OPE pollution in soils may be derived from atmospheric deposition, road runoff and vehicular traffic emission, and wastewater/reclaimed water irrigation and sludge application, their contributions were accounting for 62.4, 17.6, and 20.0%, respectively. As compared to the results from other studies, the pollution of OPEs in the urban soils of Shenyang is relatively serious.

Thermokinetics of lithium extraction with the novel extraction systems (tri-isobutyl phosphate + ionic liquid + kerosene)

Abstract The advanced micro-calorimetry and advanced thermokinetics software (AKTS) were employed to investigate the extraction thermokinetics of lithium extraction with the extractive systems [tri-isobutyl phosphate (TIBP) + ionic liquids (ILs) + kerosene] at (298.15, 308.15 and 323.15) K. The reaction heats of the system at different temperatures were experimentally determined, and the variation of reaction progresses and rates versus time were obtained for the two extractive systems at different temperatures. It was found that the reaction progress and extraction rate are accelerated while the extraction efficiencies of lithium ion are in reverse with the increasing of temperature. In addition, the activation energy and pre exponential factor for the two extractive systems are shifty regularly with the reaction progress.

Spatial Distribution and Seasonal Variation of Organophosphate Esters in Air above the Bohai and Yellow Seas, China.

Nine organophosphate esters (OPEs) were investigated in air samples collected over the Bohai and Yellow Seas (East Asia) during a research cruise between June 28 and July 13, 2016. These same OPEs were quantified at a research site (North Huangcheng Island, NHI) in the middle of the Bohai Strait from May 16, 2015, to March 21, 2016. The median total OPE (ΣOPE) concentration over the Bohai and Yellow Seas was 280 pg/m3. Tris(1-chloro-2-propyl) (TCPP) was the most abundant OPE, followed by tris(2-chloroethyl) phosphate (TCEP), tri-iso-butyl phosphate (TiBP), and tri-n-butyl phosphate (TnBP). Particle-bound OPEs accounted for 51 ± 21% of the total OPEs. On NHI, the median ΣOPE concentration was 210 pg/m3, and the average particle-bound fraction was 82 ± 17%. For samples collected on NHI, significant negative linear correlations were found between the gaseous OPEs and 1/T (T: temperature (K)) (except TDCP, TPeP, and TCP). Among the 79 investigated samples, significant correlations between the measured OPE gas/particle partitioning coefficients (Kp,m) and subcooled liquid pressure (PL◦) (p < 0.05) were found for only 14 samples, suggesting that OPEs have low potential to achieve equilibrium or ascribe to the artificial sampling. The annual dry deposition input of OPEs into the Bohai and Yellow Seas is estimated to be 12 tons/year.

Occurrences and distribution characteristics of organophosphate ester flame retardants and plasticizers in the sediments of the Bohai and Yellow Seas, China

Concentrations and distribution characteristics of organophosphate esters (OPEs) in surface sediment samples were analyzed and discussed for the first time in the open Bohai Sea (BS) and Yellow Sea (YS). Three halogenated OPEs [tris-(2-chloroethyl) phosphate (TCEP), tris-(1-chloro-2-propyl) phosphate (TCPP), and tris-(1,3-dichloro-2-propyl) phosphate (TDCPP)] and five non-halogenated OPEs [tri-isobutyl phosphate (TiBP), tri-n-butyl phosphate (TnBP), tripentyl phosphate (TPeP), triphenyl phosphate (TPhP) and tris-(2-ethylhexyl) phosphate (TEHP)] were detected in this region. The concentrations of eight OPEs in total (Σ8OPEs) ranged from 83 to 4552pgg−1dry weight (dw). The halogenated OPEs showed higher abundances than the non-halogenated ones did, with TCEP, TCPP, and TEHP the main compounds. Generally, concentrations of OPEs in the BS were higher than those in the YS. Riverine input (mainly the Changjiang Diluted Water (CDW)) and deposition effect in the mud areas might have influenced the spatial distributions of OPEs. Correlation between OPE concentrations and total organic carbon (TOC) indicated TOC was an effective indicator for the distribution of OPEs. Inventory analysis of OPEs implied that sea sediment might not be the major reservoir of these compounds.

Occurrence and spatial distribution of organophosphorus flame retardants and plasticizers in the Bohai and Yellow Seas, China

Seawater samples from 50 sites in the BS and YS were collected to investigate the spatial distribution of 7 OPs. Concentrations of the total OPs (ƩOPs) in the BS and YS ranged from 8.12ngL−1 to 98.04ngL−1 with a geometric mean (GM) of 23.70ngL−1. Tris(1-chloro-2-propyl) phosphate (TCPP) was the dominant compound, followed by tris(2-chloroethyl) phosphate (TCEP) and triphenylphosphine oxide (TPPO). The ƩOPs together with the most commonly detected individual OPs (TCPP, TCEP, tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tri-iso-butyl phosphate (TiBP), triphenyl phosphate (TPhP), and TPPO) tended to decrease from nearshore to offshore and from the surface to the bottom seawaters, indicating major land-based sources. Furthermore, the Yellow Sea Cold Water Mass (YSCWM), Changjiang Diluted Water (CDW), Taiwan Warm Current (TaWC), and Subei Coastal Water (SCW) influenced the horizontal and vertical distributions of the OPs in the study area.

Organophosphate Ester Flame Retardants and Plasticizers in Ocean Sediments from the North Pacific to the Arctic Ocean.

The presence of organophosphate ester (OPE) flame retardants and plasticizers in surface sediment from the North Pacific to Arctic Ocean was observed for the first time during the fourth National Arctic Research Expedition of China in the summer of 2010. The samples were analyzed for three halogenated OPEs [tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(dichloroisopropyl) phosphate], three alkylated OPEs [triisobutyl phosphate (TiBP), tri-n-butyl phosphate, and tripentyl phosphate], and triphenyl phosphate. Σ7OPEs (total concentration of the observed OPEs) was in the range of 159-4658 pg/g of dry weight. Halogenated OPEs were generally more abundant than the nonhalogenated OPEs; TCEP and TiBP dominated the overall concentrations. Except for that of the Bering Sea, Σ7OPEs values increased with increasing latitudes from Bering Strait to the Central Arctic Ocean, while the contributions of halogenated OPEs (typically TCEP and TCPP) to the total OPE profile also increased from the Bering Strait to the Central Arctic Ocean, indicating they are more likely to be transported to the remote Arctic. The median budget of 52 (range of 17-292) tons for Σ7OPEs in sediment from the Central Arctic Ocean represents only a very small amount of their total production volume, yet the amount of OPEs in Arctic Ocean sediment was significantly larger than the sum of polybrominated diphenyl ethers (PBDEs) in the sediment, indicating they are equally prone to long-range transport away from source regions. Given the increasing level of production and usage of OPEs as substitutes of PBDEs, OPEs will continue to accumulate in the remote Arctic.

Third phase formation in the extraction of Th(NO3)4 by Tri-sec-butyl phosphate: a comparison with Tri-n-butyl phosphate

Abstract Earlier studies carried out in our laboratory indicated that Tri-sec-butyl phosphate (TsBP) is a potential extractant for U/Th separation. Also, the third phase formation tendency of TsBP is lower compared to its isomers, Tri-n-butyl-phosphate (TBP) and Tri-iso-butyl phosphate (TiBP). In this context, the extraction and third phase formation behaviour of 1.1 M solutions of TiBP and TsBP in n-dodecane in the extraction of Th(IV) from 1 M HNO3 at 303 K over a wide range of Th concentrations were investigated in the present study and the results are compared with the literature data on TBP system. Concentrations of Th(IV) and HNO3 loaded in the organic phase before third phase formation (biphasic region) as well as in third phase and diluent-rich phase after third phase formation (triphasic region) were measured as a function of equilibrium aqueous phase Th(IV) concentration. The density of loaded organic phase was also measured at various Th(IV) concentrations. The extraction profiles in the biphasic region indicated that extraction of Th(IV) by TBP is higher than that of TiBP which in turn is higher than that of TsBP. Extractant concentration in the diluent-rich phase and third phase was measured for the triphasic region.

Comparision in the solvent extraction behavior of uranium (VI) in some trialkyl phosphates in ionic liquid

Abstract Higher homologs of trialkyl phosphates (TAlP) are proposed for reprocessing of fast reactor fuels. Solvent extraction behavior of U(VI) from nitric acid medium was studied in some TAlP present in 1-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C8mim][NTf2]) ionic liquid. The extractants investigated were tri-n-propylphosphate (TPP), tri-n-butylphosphate (TBP), tri-n-amylphosphate (TAP), tri-n-octylphosphate (TOP), tri-iso-amylphosphate (TIAP) and tri-iso-butylphosphate (TIBP). The extraction of uranium (VI) was investigated as a function of various parameters, such as the equilibration time, [HNO3], [TAlP], temperature and nature of ionic liquid cation. The distribution ratios of U(VI) increased with an increase in the concentration of nitric acid and decreases in the order TOP&gt;TAP~ TIAP&gt;TBP~TIBP&gt;TPP. The stoichiometry of the extraction was determined by slope analysis of the extraction data. Distribution ratios of U (VI) were determined at various temperatures and the thermodynamic parameters were derived. Quantitative stripping of uranium from the loaded ionic liquid phase was achieved using dilute nitric acid.

Solvent Extraction of Selenium in Hydrochloric Acid Media by Using Triisobutyl Phosphate and Triisobutyl Phosphate/Dodecanol Mixture

The objective of the present study was to investigate the mechanism of selenium extraction in hydrochloric media by solvent extraction which was carried out in two steps. First, the extraction of selenium by triisobutyl phosphate (TIBP) was employed, and then in the next step, Dodecanol was used as a modifier. The effect of concentration of acid, concentration of TIBP in the organic phase, pH, temperature and modifier on the extraction of selenium(IV) was studied. The results showed that the extraction of selenium by TIBP was not favorable especially in less pH values. But there was a sharp and sudden increase in the extraction of selenium(IV) at the pH around 8–8.5 that was evaluated and proved by comparing the ORP graph of selenium extraction from hydrochloric media with Pourbaix graph of selenium in the hydrochloric media, and FTIR spectra at three points, before, after and at the peak of extraction. Thermodynamic of the process was also studied. The enthalpy of the process was calculated by the plot of log D versus 1/T × 10−4 and the value of enthalpy was estimated to be equal to −15.4 J/mol which indicated an exothermic reaction. In the next step, the extraction of selenium by TIBP in the presence of Dodecanol as a modifier was surveyed. The result represented that the extraction of selenium increased up to 99 % by using Dodecanol as a modifier at low pH values.

Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?

This study aims to determine the occurrence of 10 OPFRs (including chlorinated, nonchlorinated alkyl and aryl compounds) in influent, effluent wastewaters and partitioning into sludge of 5 wastewater treatment plants (WWTP) in Catalonia (Spain). All target OPFRs were detected in the WWTPs influents, and the total concentration ranged from 3.67µgL−1 to 150µgL−1. During activated sludge treatment, most OPFRs were accumulated in the sludge at concentrations from 35.3 to 9980ngg−1dw. Chlorinated compounds tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2,3-dichloropropyl) phosphate (TDCPP) were not removed by the conventional activated sludge treatment and they were released by the effluents at approximately the same inlet concentration. On the contrary, aryl compounds tris(methylphenyl) phosphate (TMPP) and 2-ethylhexyl diphenyl phosphate (EHDP) together with alkyl tris(2-ethylhexyl) phosphate (TEHP) were not detected in any of the effluents. Advanced oxidation processes (UV/H2O2 and O3) were applied to investigate the degradability of recalcitrant OPFRs in WWTP effluents. Those detected in the effluent sample (TCEP, TCIPP, TDCPP, tributyl phosphate (TNBP), tri-iso-butyl phosphate (TIBP) and tris(2-butoxyethyl) phosphate (TBOEP)) had very low direct UV-C photolysis rates. TBOEP, TNBP and TIBP were degraded by UV/H2O2 and O3. Chlorinated compounds TCEP, TDCPP and TCIPP were the most recalcitrant OPFR to the advanced oxidation processes applied. The study provides information on the partitioning and degradability pathways of OPFR within conventional activated sludge WWTPs.

Organophosphorous flame retardants in biota from Svalbard, Norway

Eight arctic species, including fish, birds and mammals, from diverse habitats (marine and terrestrial) within the Svalbard Archipelago, Norway, were screened for 14 organophosphorus flame retardant (PFR) compounds. Ten PFRs were detected: tris(2-chloroethyl)phosphate (TCEP), tris(2-chloroisopropyl)phosphate (TCIPP), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), triphenyl phosphate (TPHP); 2-ethylhexyl diphenyl phosphate (EHDPP); tris(2-butoxyethyl)phosphate (TBOEP); tritolyl phosphate (TCrP); triisobutyl phosphate (TIBP); tris(2-ethylhexyl)phosphate (TEHP); and butyl diphenyl phosphate (DPhBP). The greatest number of different PFR compounds, and the highest detection frequency were measured in capelin (Mallotus villotus), and the lowest in Brünnich's guillemot (Uria lomvia). The highest concentrations of ΣPFR, as well as the highest concentration of a single PFR compound, TBOEP, were measured in arctic fox (Vulpes lagopus). The presence of PFR compounds in arctic biota indicates that these compounds can undergo long-range transport and are, to some degree, persistent and bioaccumulated. The potential for biomagnification from fish to higher trophic levels seems to be limited.

Extraction of lithium from salt lake brine with triisobutyl phosphate in ionic liquid and kerosene

Three ionic liquids(ILs), namely, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide and 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide with the triisobutyl phosphate(TIBP) and kerosene system were respectively used to extract lithium ion from salt lake brine with a high concentration ratio of magnesium and lithium experimentally. Results indicate that the highest extraction selectivity for lithium was obtained with IL 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)-sulfonyl]imide. The effects of solution pH and phase ratio R(O/A) on the extractive step and the influence of acid concentration of the stripping solution and R(O/A) on the back extraction step were also investigated systematically. The single-step extraction efficiency of lithium ion was 83.71% under the optimal extraction conditions, and the single-step back extraction efficiency was 85.61% with a 1.0 mol/L HCl in 1.0 mol/L NaCl medium as stripping agent at R(O/A)=2. The liquid-liquid extraction mechanism and the complex of the ligand with lithium were proposed.

Assessment of human hair as an indicator of exposure to organophosphate flame retardants. Case study on a Norwegian mother–child cohort

A major challenge of non-invasive human biomonitoring using hair is to assess whether it can be used as an indicator of exposure to Flame Retardants, such as Organophosphate Flame Retardants (PFRs), since the contribution of atmospheric deposition (air and/or dust) cannot be neglected. Therefore, the aim of this study was to evaluate the suitability of using human hair more thoroughly by comparison of (i) levels of PFRs in human hair (from 48 mothers and 54 children), with levels measured in dust and air in their respective households; and (ii) levels of selected PFRs in hair with the levels of corresponding PFR metabolites in matching urine samples collected simultaneously. Most PFRs (tri-n-butyl phosphate (TNBP), 2-ethyl-hexyldiphenyl phosphate (EHDPHP), tri-phenyl phosphate (TPHP), tri-iso-butyl phosphate (TIBP), and tris(2-butoxyethyl) phosphate (TBOEP)) were detected in all human hair samples, tris(2-ethylhexyl) phosphate (TEHP) and tris(1,3-dichloro-iso-propyl) phosphate (TDCIPP) in 93%, tri-cresyl-phosphate (TCP) in 69% and tris(2-chloroethyl) phosphate (TCEP) in 21% of the samples. Levels of individual PFRs ranged between <1 and 3744ng/g hair and were lower than in indoor dust from the participants' homes. Several statistically significant associations between PFR levels in human hair and PFR levels in house dust and/or air were found, e.g. Spearman correlation (rS=0.561, p<0.05) between TBOEP in children's hair and in indoor air. Also, associations were found between TDCIPP in hair and its metabolite bis(1,3-dichloro-iso-propyl) phosphate (BDCIPP) in urine; they were stronger for children (e.g. Pearson correlation rP=0.475; p=0.001) than for mothers (rP=0.395, p=0.01). Levels of diphenyl phosphate (DPHP) in mothers' and children's urine were slightly correlated (rS=0.409, p=0.008), suggesting similar sources of exposure. To the best of our knowledge, this is the first study with such design and our findings might help to understand human exposure to and body burdens of PFRs.

Organophosphorus Flame Retardants and Plasticizers in Airborne Particles over the Northern Pacific and Indian Ocean toward the Polar Regions: Evidence for Global Occurrence

Organophosphorus compounds (OPs) being applied as flame retardants and plasticizers were investigated in airborne particles over the Pacific, Indian, Arctic, and Southern Ocean. Samples taken during two polar expeditions in 2010/11, one from East Asia to the high Arctic (CHINARE 4) and another from East Asia toward the Indian Ocean to the Antarctic (CHINARE 27), were analyzed for three halogenated OPs (tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCPP) and tris(1,3-dichloro-2-isopropyl) phosphate (TDCP)), four alkylated OPs (tri-n-butyl phosphate (TnBP), tri-iso-butyl phosphate (TiBP), tris(2-butoxyethyl)phosphate (TBEP), and tris(2-ethylhexyl) phosphate (TEHP)), and triphenyl phosphate (TPhP). The sum of the eight investigated OPs ranged from 230 to 2900 pg m(-3) and from 120 to 1700 pg m(-3) during CHINARE 4 and CHINARE 27, respectively. TCEP and TCPP were the predominating compounds, both over the Asian seas as well as in the polar regions, with concentrations from 19 to 2000 pg m(-3) and 22 to 620 pg m(-3), respectively. Elevated concentrations were observed in proximity to the Asian continent enhanced by continental air masses. They decreased sharply toward the open oceans where they remained relatively stable. This paper shows the first occurrence of OPs over the global oceans proving that they undergo long-range atmospheric transport over the global oceans toward the Arctic and Antarctica.

Multi-residue method for the determination of brominated and organophosphate flame retardants in indoor dust

A new method was optimized for the simultaneous determination of several flame retardants (FRs) in indoor dust, namely polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), novel brominated flame retardants (NBFRs) and organophosphate ester flame retardants (OPFRs). The method was based on two previously validated analytical methods for NBFRs and OPFRs, which were combined in order to include even a large number of FRs. An ultrasonic extraction method and two-stage clean-up by adsorption chromatography was optimized using an indoor dust standard reference material (SRM 2584). The 1st cleanup step was essential for fractionation of analytes in the dust extracts, while the 2nd step was important for the further removal of interferences. Analysis of cleaned dust extracts was performed with gas chromatography electron impact ionization mass spectrometry for OPFRs, gas chromatography electron capture negative ionization mass spectrometry for PBDEs and NBFRs and liquid chromatography electrospray ionization tandem mass spectrometry for HBCDs. Method validation by matrix spiking demonstrated good accuracy ranging from 81 to 130%. Matrix effects were investigated by spiking sodium sulfate and dust with analyte standards. Typical recoveries ranged between 80 and 110% at both spiking levels, though occasional deviations were observed at low spiking concentrations. Precision between different days was generally below 24% relative standard deviation (RSD) at low concentrations and below 11% RSD at high concentrations. Method limits of quantification for BFRs ranged between 0.04 (BDE 28) and 17ng/g (BDE 209), 6ng/g for sum HBCDs, and for OPFRs between 10 (triphenyl phosphate) and 370ng/g (tri-isobutyl phosphate). The method was applied to SRM 2585 and to a set of indoor dust samples from various countries. The newly developed method will be employed for the monitoring of human exposure via dust ingestion to phased-out and alternate FRs.

Occurrence and fate of organophosphorus flame retardants and plasticizers in urban and remote surface waters in Germany

Within this study, concentration levels and distribution of the organophosphates tris(2-chloroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris(2-butoxyethyl) phosphate (TBEP), tri-iso-butyl phosphate (TiBP), and tri- n-butyl phosphate (TnBP) were investigated at nine lentic surface waters under different anthropogenic impact between June 2007 and October 2009. Furthermore, the possibility of in-lake photochemical degradation of the analytes was studied in laboratory experiments using spiked ultrapure water and lake water samples incubated in Teflon bottles (which transmit sunlight). TBEP, TiBP, and TnBP were photochemically degraded in spiked lake water samples upon exposure to sunlight. Organophosphate concentrations in the more remote lakes were often below or close to the limits of quantification (LOQ). TCPP was the substance with the highest median concentration in rural volcanic lakes (7–18 ng L −1) indicating an atmospheric transport of the compound. At urban lakes their median concentrations were in the range of 23–61 ng L −1 (TCEP), 85–126 ng L −1 (TCPP), <LOQ–53 ng L −1 (TBEP), 8–10 ng L −1 (TiBP), and 17–32 ng L −1 (TnBP). High variability but no significant seasonal trends were observed for all five organophosphates in urban lake water samples.

Seasonal fluctuations of organophosphate concentrations in precipitation and storm water runoff

To investigate seasonal fluctuations and trends of organophosphate (flame retardants, plasticizers) concentrations in rain and snow, precipitation samples were collected in 2007–2009 period at a densely populated urban sampling site and two sparsely populated rural sampling sites in middle Germany. In addition, storm water runoff was sampled from May 2008 to April 2009 at an urban storm water holding tank (SWHT). Samples were analyzed for tris(2-chloroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris(1,3-dichloro-2-propyl) phosphate (TDCP), tris(2-butoxyethyl) phosphate (TBEP), tri-iso-butyl phosphate (TiBP), and tri-n-butyl phosphate (TnBP) by gas chromatography–mass spectrometry after solid phase extraction. Among the six analyzed organophosphates (OPs), TCPP dominated in all precipitation and SWHT water samples with maximum concentrations exceeding 1000 ng L −1. For all analytes, no seasonal trends were observed at the urban precipitation sampling site, although atmospheric photooxidation was expected to reduce particularly concentrations of non-chlorinated OPs during transport from urban to remote areas in summer months with higher global irradiation. In the SWHT a seasonal trend with decreasing concentrations in summer/autumn is evident for the non-chlorinated OPs due to in-lake degradation but not for the chlorinated OPs. Furthermore, an accumulation of OPs deposited in SWHTs was observed with concentrations often exceeding those observed in wet precipitation. Median concentrations of TCPP (880 ng L −1), TDCP (13 ng L −1) and TBEP (77 ng L −1) at the SWHT were more than twice as high as median concentrations measured at the urban precipitation sampling site (403 ng L −1, 5 ng L −1, and 21 ng L −1 respectively).