Determination Of Polybrominated Biphenyls Research Articles

Determination of polybrominated biphenyls in environmental water samples by ultrasound-assisted dispersive liquid-liquid microextraction followed by high-performance liquid chromatography

Dispersive liquid-liquid microextraction (DLLME) is an extraordinarily fast and effective sample preparation procedure. In this work, a simple, rapid, and sensitive method using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with high-performance liquid chromatography (HPLC) has been developed for rapid determination polybrominated biphenyls (PBBs) in real water samples. The key parameters affecting the extraction efficiency including the extractant, dispersant, the volumes of extractant and dispersant, and ultrasound time were optimized, and further validated by orthogonal array design (OAD), a L16 (44) matrix was applied for the identification of optimized extraction parameters, and the optimized method was successfully applied to the analysis of environmental water sample. The results showed good linearity (correlation coefficients > 0.9942), low limits of detection (0.11–0.12 μg L−1), wide linear ranges (0.5–1000 μg L−1), and acceptable repeatability (relative standard deviation, RSD < 5.2% for intra-day, RSD <6.3% for inter-day). Moreover, the method is further applied to the analysis of four PBBs in real samples with good recoveries (75.8%–105%) and satisfactory precisions (RSD < 6.5%). The optimized conditions provided enrichment factors (EFs) for PBBs of 211–245.

RoHS Regulation: Challenges in the Measurement of Substances of Concern in Industrial Products by Different Analytical Techniques

The European Union’s as well as India’s reduction of hazardous materials (RoHS) directives state that producers of certain categories of electrical and electronic equipments will not be able to offer for sale any product that contains any of hazardous substances: Cd, Pb, Hg, Cr6+, polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE), bis(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP) beyond the specified limits. Allowable concentration levels in any homogeneous material contained within a product are extremely low: 0.01% for Cd and 0.1% for other substances by weight. These substances when present in quantities in excess of the permissible limits are considered hazardous and damaging to the environment and human health. With the introduction of the RoHS Directive many manufacturing companies in the world are pursuing chemical testing as a means to identify and quantify these hazardous substances. This article presents various testing methods that are currently available to the manufacturing firms who need to generate data to prove that their products are compliant to the RoHS directive. The utility of portable X-ray fluorescence spectrometer (XRF) and also the potential of laser-induced breakdown spectrometer (LIBS) for rapid screening applications is described. For quantitative determination of Pb, Cd, Hg and Cr, the role of instrumental analytical techniques such as atomic absorption spectrometry, XRF, instrumental neutron activation analysis, inductively coupled plasma optical emission spectrometry, the inductively coupled plasma mass spectrometry (ICP-MS), LIBS and the potential of the new analytical technique, microwave plasma atomic emission spectrometry is discussed. Applicability of hyphenated techniques such as HPLC-ICP-MS for Cr6+, GC–MS for the determination of PBB, PBDE and phthalates, and the importance of certified reference materials, challenges and future trends are presented.

Determination of brominated flame retardants in electrical and electronic equipments with microwave-assisted extraction and gas chromatography–mass spectrometry

Determination of brominated flame retardants in electrical and electronic equipments (EEE) was achieved through microwave-assisted extraction (MAE) and gas chromatography–mass spectrometry. Polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) including mono-brominated through deca-brominated congeners were qualified and quantified with good linearity (0.9963–0.9998) and repeatability (RSD, 1.1–8.1%). Multivariable orthogonal experimental design was used to optimize the MAE parameters. Extraction temperature and time were the most significant factors for extraction process. The extractants were cleaned up with SPE method after extraction. Recoveries of spiked blank samples ranged from 72.4% to 108.4% for most of the analytes. The method was applied to the determination of PBBs and PBDEs in several kinds of real EEE samples. It was found that no detectable level of PBBs was detected among them. Different contents of PBDEs were tested in the tested samples and the total contents ranged from 25.0 ng g −1 to 194.0 ng g −1. The proposed approach demonstrated an environmentally friendly and convenient alternative, which only consumed 10 mL hexane to microwave extraction for 10 min at 100 °C.

Determination of polybrominated biphenyls in serum by negative chemical ionization mass spectrometry.

Determination of polybrominated biphenyls in serum by negative chemical ionization mass spectrometry.

Determination of Polybrominated Biphenyl Residues in Dry Animal Feeds

A new procedure is described for the determination of polybrominated biphenyls (PBBs) in dry animal feeds and developmental results are discussed. Finely ground feed is packed into a chromatographic column containing Celite and then eluted with methylene chloride. The concentrated extract is cleaned up by elution with petroleum ether through Florisil before gas-liquid chromatographic quantitation. Chromatograms thus obtained were essentially free of the interfering peaks encountered when using AOAC methods for pesticide residues in dry products. Results of feed analyses by the proposed procedure averaged 30% higher than those obtained by AOAC procedures. Recoveries of PBBs from samples fortified at levels of 0.04 to 0.4 ppm ranged from 90 to 104%, with an average of 98%.

Determination of Polybrominated Biphenyl Residues in Dairy Products

A method for the determination of polybrominated biphenyls (PBBs) in dairy products is described. Fat is extracted from the products by the official AOAC method. The PBB residues are separated from the fatty material by gel permeation chromatography prior to gas-liquid chromatographic (GLC) quantitation. An additional cleanup using petroleum ether elution through a miniature Florisil column is necessary for thin layer chromatographic (TLC) confirmation. Recoveries of PBBs from samples fortified at levels from 0.1 to 0.5 ppm ranged from 94 to 104% with an average of 99%. GLC sensitivity permits the estimation of PBB residue levels as low as 0.007 ppm. Routine TLC confirmation is limited by sensitivity to greater than or equal to 0.2 ppm.