Leaching behavior of Sb and Br from E-waste flame retardant plastics.

The improper disposal of E-waste flame retardant plastics laden with antimony (Sb) and bromine (Br) has brought enormous environmental hazards, however, rare information on the effective removal of Sb and Br is available. In this study, through building an alkaline sulfide system under hydrothermal conditions, Sb and Br were simultaneously extracted from flame retardant plastic with high efficiency of 85.60% and 90.13%, respectively. Sulfur ion through mass transfer reacted with encapsulated Sb2O3 to form safe and non-toxic SbS33-. Alkaline solution trapped the Br through substitution or neutralization reaction to inhibit the formation of brominated organic compounds. The results showed that the optimum temperature, residence time, Na2S and NaOH concentration for hydrothermal removal of Sb and Br were 220 °C, 2 h, 50 g/L and 20 g/L. The results also revealed that both Na2S and NaOH played an interrelated role in the process of Sb removal. However, NaOH was the only factor controlling the process of debromination. Moreover, the FTIR structure of plastic after alkaline sulfide hydrothermal treatment remained unchanged, which implies that the treated plastic can be reused, and is an added advantage of this technology. The TG-DTG analysis proved the effectiveness of alkaline sulfide hydrothermal treatment in removing Sb and Br.

Feasibility of microwave-induced combustion combined with inductively coupled plasma mass spectrometry for bromine and iodine determination in human nail.

RATIONALE: Bromine and iodine have important physiological functions; however, in inadequate concentration, they can also cause several physiological problems. Their mobility assessment in human organisms through biological sampling may help clarify some doubts related to metabolic routes, which are still not well elucidated. In this context, a suitable analytical method for this purpose should be developed. METHODS: An analytical method for determining ultratrace levels of bromine and iodine in human nail samples was developed. Inductively coupled plasma mass spectrometry (ICP-MS) using a conventional nebulization system was immediately chosen as the determination tool because of its powerful sensitivity and selectivity. Sample preparation methods including microwave-induced combustion (MIC), microwave-assisted extraction, and microwave-assisted digestion were evaluated. The compatibility of the final solutions with ICP-MS analysis was considered while the method was developed. RESULTS: MIC was chosen as the most suitable method for the sample preparation for determining the levels of bromine and iodine in human nail samples using ICP-MS. Unlike other sample preparation methods, this one fully eliminated interferences related to the carbon content and memory effects. Sample masses up to 100 mg were efficiently digested, and the analytes were quantitatively absorbed using only 50 mmol L-1 NH4 OH solution. Recoveries ranged from 93% to 102%, and the relative standard deviation was < 8%. CONCLUSIONS: The proposed analytical method presents important characteristics for routine analysis. It allows ultratrace determination even when low sample masses are used because of the low blank values, reduced volume of reagents, and powerful detectability using ICP-MS.

A fast and feasible method for Br and I determination in whole egg powder and its fractions by ICP-MS.

A method for Br and I determination in whole egg powder and its fractions (egg white and yolk) was developed by combining microwave-induced combustion (MIC) and inductively coupled plasma mass spectrometry (ICP-MS). Using the MIC method, 350mg of whole egg powder and its fractions were efficiently digested using 50mmolL-1NH4OH as an absorbing solution. The limits of detection for Br and I using the MIC method followed by ICP-MS determination were 0.039 and 0.015µgg-1, respectively. Using the proposed method, agreements with the reference values between 97 and 104% for Br and I were obtained by analysis of reference material NIST 8435. Finally, it was possible to observe that Br concentration (4.59-5.29µgg-1) was higher than I (0.150-2.28µgg-1) for all the evaluated samples.

Bromine and bromide content in soils: Analytical approach from total reflection X-ray fluorescence spectrometry.

Monitoring total bromine and bromide concentrations in soils is significant in many environmental studies. Thus fast analytical methodologies that entail simple sample preparation and low-cost analyses are desired. In the present work, the possibilities and drawbacks of low-power total reflection X-ray fluorescence spectrometry (TXRF) for the determination of total bromine and bromide contents in soils were evaluated. The direct analysis of a solid suspension using 20 mg of fine ground soil (<63 µm) gave a 3.7 mg kg(-1) limit of detection for bromine which, in most cases, was suitable for monitoring total bromine content in soils (Br content range in soils = 5-40 mg kg(-1)). Information about bromide determination in soils is also possible by analyzing the Br content in water soil extracts. In this case, the TXRF analysis can be directly performed by depositing 10 µL of the internal standardized soil extract sample on a quartz glass reflector in a measuring time of 1500 s. The bromide limit of detection by this approach was 10 µg L(-1). Good agreement was obtained between the TXRF results for the total bromine and bromide determinations in soils and those obtained by other popular analytical techniques, e.g. energy dispersive X-ray fluorescence spectrometry (total bromine) and ionic chromatography (bromide). As a study case, the TXRF method was applied to study bromine accumulation in two agricultural soils fumigated with a methyl bromide pesticide and irrigated with regenerated waste water.

Direct spectral analysis of tea samples using 266 nm UV pulsed laser-induced breakdown spectroscopy and cross validation of LIBS results with ICP-MS.

Tea is one of the most common and popular beverages spanning vast array of cultures all over the world. The main nutritional benefits of drinking tea are its anti-oxidant properties, presumed protection against certain cancers, inhibition of inflammation and possible protective effects against diabetes. Laser induced breakdown spectrometer (LIBS) was assembled as a powerful tool for qualitative and quantitative analysis of various brands of tea samples using 266 nm pulsed UV laser. LIBS spectra for six brands of tea samples in the wavelength range of 200-900 nm was recorded and all elements present in our tea samples were identified. The major toxic elements detected in several brands of tea samples were bromine, chromium and minerals like iron, calcium, potassium and silicon. The spectral assignment was conducted prior to the determination of concentration of each element. For quantitative analysis, calibration curves were drawn for each element using standard samples prepared in known concentration in the tea matrix. The plasma parameters (electron temperature and electron density) were also determined prior to the tea samples spectroscopic analysis. The concentration of iron, chromium, potassium, bromine, copper, silicon and calcium detected in all tea samples was between 378-656, 96-124, 1421-6785, 99-1476, 17-36, 2-11 and 92-130 mg L(-1) respectively. The limits of detection estimated for Fe, Cr, K, Br, Cu, Si, Ca in tea samples were 22, 12, 14, 11, 6, 1 and 12 mg L(-1) respectively. To further confirm the accuracy of our LIBS results, we determined the concentration of each element present in tea samples by using standard analytical technique like ICP-MS. The concentrations detected with our LIBS system are in excellent agreement with ICP-MS results. The system assembled for spectral analysis in this work could be highly applicable for testing the quality and purity of food and also pharmaceuticals products.

Study of the transference rules for bromine in waste printed circuit boards during microwave-induced pyrolysis.

The production of waste printed circuit boards (WPCBs) has drawn increasing global concern, especially because the high bromine (Br) content (5-15%) places obstacles in the way of simple disposal techniques. Microwave-induced pyrolysis of WPCBs provides a promising way to dispose of these hazardous and resource-filled wastes. The transference rules for Br during microwave-induced pyrolysis have been investigated experimentally. It was found that the microwave energy could be used more efficiently to accelerate the heating rate and improve the final pyrolysis temperature by adding some activated carbon (AC) as microwave absorbents. The high temperature and rapid pyrolysis process promoted the yields of gaseous products and the decomposition of brominated compounds into hydrogen bromide and then benefited the capture of Br and the debromination of byproducts. The application of a calcium carbonate (CaCO3) layer overhead led to over 95% debromination of the liquid products and over 50% capture of the total Br. It can be concluded that the presented method is suitable for the control of Br transference in the recycling of WPCBs. This method can also be extended to the disposal of the electronic scraps.

Biodegradation of bromoamine acid using combined airlift loop reactor and biological activated carbon.

The biodegradation of bromoamine acid (BAA) in a combined airlift loop reactor (ALR) and biological activated carbon (BAC) system was investigated. The results showed that the ALR using Sphingomonas xenophaga as inoculum and granular activated carbon (GAC) as carrier, could run steadily for over 3 months at less than 950 mg L(-1) BAA. And the efficiencies of BAA decolorization and COD removal in ALR reached about 90% and 50% within 12h, respectively. When it was further aerated for another 12h, the ALR effluent gradually became yellow due to the auto-oxidation of BAA decolorization products which were identified by HPLC-MS. Further biotreatment of the ALR effluent using BAC showed that the efficiency of TOC removal could reach 90%. Moreover, the release efficiencies of Br(-) and SO(4)(2-) were 73.5% and 67.4%, respectively. It indicated that BAC system was effective in the biodegradation of the auto-oxidative BAA decolorization products.

Microwave assisted extraction of iodine and bromine from edible seaweed for inductively coupled plasma-mass spectrometry determination.

The feasibility of microwave energy to assist the solubilisation of edible seaweed samples by tetramethylammonium hydroxide (TMAH) has been investigated to extract iodine and bromine. Inductively coupled plasma-mass spectrometry (ICP-MS) has been used as a multi-element detector. Variables affecting the microwave assisted extraction/solubilisation (temperature, TMAH volume, ramp time and hold time) were firstly screened by applying a fractional factorial design (2(5-1)+2), resolution V and 2 centre points. When extracting both halogens, results showed statistical significance (confidence interval of 95%) for TMAH volume and temperature, and also for the two order interaction between both variables. Therefore, these two variables were finally optimized by a 2(2)+star orthogonal central composite design with 5 centre points and 2 replicates, and optimum values of 200 degrees C and 10 mL for temperature and TMAH volume, respectively, were found. The extraction time (ramp and hold times) was found statistically non-significant, and values of 10 and 5 min were chosen for the ramp time and the hold time, respectively. This means a fast microwave heating cycle. Repeatability of the over-all procedure has been found to be 6% for both elements, while iodine and bromine concentrations of 24.6 and 19.9 ng g(-1), respectively, were established for the limit of detection. Accuracy of the method was assessed by analyzing the NIES-09 (Sargasso, Sargassum fulvellum) certified reference material (CRM) and the iodine and bromine concentrations found have been in good agreement with the indicative values for this CRM. Finally, the method was applied to several edible dried and canned seaweed samples.

PCDD/F in source-sorted waste fractions and emissions from their co-combustion with reed canary-grass.

The dry combustible fraction of source-sorted household waste, including material that would otherwise be recycled, was mixed with the energy crop reed canary-grass (Phalaris arundinacea L.), and combusted as briquettes in 150 and 600 kW biofuel-boilers without advanced cleaning systems. The source-sorted waste was further sorted and characterized according to its material and chemical contents. The bulk of the waste's chlorine content came from the non-package plastic fraction, whereas 90-95% of summation operator PCDD/F (74-90% of WHO-TEQ) originated from the textile fraction. The sources of the dioxins in the waste fractions are discussed. The balance of dioxin levels was negative, i.e., the amounts of dioxins output in the flue gas were lower than those input in the fuel, except when there were operational disturbances in the combustion. In one of the combustion trials the total levels of dioxins in the flue-gas and ashes were also lower than the input levels. The use of additional cleaning equipment will be needed to ensure that emissions of dioxins and hydrochloric acid will be below legal limits.

[Bromo- and iodo-containing alkaloids from marine microorganisms and sponges]. / Brom- i iodsoderzhashchie alkaloidy morskikh mikroorganizmov i gubok.

The taxonomic distribution, structure, and biological activity of halogenated alkaloids isolated from marine microorganisms and sponges are reviewed. The structures of nearly 140 natural bromo- and iodo-containing alkaloids are shown.

5-Bromouridylyl-(3-5)-adenosine isolated from 5-bromouracil-induced filaments of Escherichia coli.

A dinucleoside monophosphate was isolated from 5-bromouracil-induced filaments of a thymine auxotroph of Escherichia coli K-12. The dinucleoside monophosphate was fractioned from a [(14)C]5-bromouracil-labeled perchloric acid extract using Dowex-1-formate ion-exchange chromatography. Sephadex chromatography revealed its molecular weight to be 710. Snake venom phosphodiesterase digest of the dinucleoside monophosphate yielded [(14)C]5-bromouridine and adenosine 5'-monophosphate. The presence of [(14)C]5-bromouracil in bacterial ribonucleic acid indicates that ribonucleic acid, which had incorporated 5-bromouracil, was the probable source of this dinucleoside monophosphate, 5-bromouridylyl-(3' --> 5')-adenosine.