Determination of brominated phenols in water samples by on-line coupled isotachophoresis with capillary zone electrophoresis

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2010-2012)

CE has been alive for over two decades now, yet its sensitivity is still regarded as being inferior to that of more traditional methods of separation such as HPLC. As such, it is unsurprising that overcoming this issue still generates much scientific interest. This review continues to update this series of reviews, first published in Electrophoresis in 2007, with updates published in 2009 and 2011 and covers material published through to June 2012. It includes developments in the field of stacking, covering all methods from field amplified sample stacking and large volume sample stacking, through to isotachophoresis, dynamic pH junction and sweeping. Attention is also given to online or inline extraction methods that have been used for electrophoresis.

Hydroxylated PBDEs and brominated phenolic compounds in particulate matters emitted during recycling of waste printed circuit boards in a typical e-waste workshop of South China

The hydroxylated PBDEs (OH-PBDEs) and brominated phenolic compounds in aerosol samples from a printed circuit boards recycling workshop were characterized. The results show that OH-PBDEs, which are naturally occurring compounds or metabolism of PBDEs, could also be emitted from the e-waste recycling. Five OH-PBDEs, several unidentified mono-OH-PBDE and di-OH-PBDE congeners were detected. The concentration of ∑OH-PBDEs was 1.74-4.22 ng m(-3) (average of 2.66 ng m(-3)), with 6-OH-BDE-47 (0.329 ng m(-3)) as the most abundant identified congener. The total concentration of di- to tri-brominated phenols (BPs) was 18.8-32.0 ng m(-3) (average of 26.3 ng m(-3)) with 2,4,6-triBP as the most abundant congener. These findings suggest that the recycling of printed circuit boards represent a strong source of OH-PBDEs and BPs to the atmosphere. Additionally, some phenolic compounds including brominated bisphenol A, hydroxylated polybrominated biphenyl species and etc. were also identified.

Review of recent developments of on-line sample stacking techniques and their application in capillary electrophoresis

Capillary electrophoresis (CE) has become one of the most useful tools in separation science because of its high separation efficiency, low cost, versatility, ease of sample preparation and automation. However, some limitations of CE, such as poor concentration sensitivity due to its lower sample loading and shorter optical path length, limits its further applications in separation science. In order to solve this problem, various on-line sample preconcentration techniques such as transient isotachophoresis preconcentration, field-enhanced sample stacking, micelle to solvent stacking, micelle collapse, dynamic pH junction, sweeping, solid phase extraction, single drop microextraction and liquid phase microextraction have been combined with CE. Recent developments, applications and some variants together with different combinations of these techniques integrating in CE are reviewed here and our discussions will be confined to the past three years (2008–2011).

Biodegradation kinetics and mechanism of 2,4,6-tribromophenol by Bacillus sp. GZT: a phenomenon of xenobiotic methylation during debromination

A strain Bacillus sp. GZT capable of debrominating and mineralizing 2,4,6-tribromophenol (TBP) was isolated and characterized by morphological observation, biochemical and physiological identification as well as 16S rRNA sequence analysis. Biodegradation kinetics experiments demonstrated that initial TBP concentration had a predominant effect on degradation efficiency. Within 120h, the highest TBP degradation and debromination efficiencies were up to 93.2% and 89.3%, respectively, under the optimum condition. Ten metabolic intermediates including five brominated compounds, three oxidative products and two cellular metabolites were all identified by gas chromatography-mass spectrometer, and six key intermediates were doubly validated by authentic standards. The proposed biodegradation mechanism inferred that reductive debromination as a major degradation pathway could simultaneously take place at ortho- and para-positions on TBP, while methylated debromination was also found as a minor degradation pathway during this process. Within 148h degradation, nearly one-third of 3mg/L TBP could be completely mineralized.