Measurements of selected brominated flame retardants in nursing women: implications for human exposure.

We have examined several emerging brominated flame retardants (BFRs) including 2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (TBB), bis(2-ethylhexyl) tetrabromophthalate (TBPH), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), 4,5,6,7-tetrabromo-1,1,3-trimethyl-3-(2,3,4,5-tetrabromophenyl)-indane (OBIND), and decabromodiphenyl ethane (DBDPE) in paired human maternal serum (n = 102) and breast milk (n = 105) collected in 2008-2009 in the Sherbrooke region in Canada. Three legacy BFRs were also included in the study for comparison: decabromobiphenyl (BB-209), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), and 2,2',4,4',5,5'-hexabromodiphenyl ethers (BDE-153). TBB, BB-153, and BDE-153 had detection frequencies greater than 55% in both serum and milk samples.

Hexachloronorbornene-based flame retardants in humans: levels in maternal serum and milk.

Five hexachloronorbornene-based flame retardants, Dechlorane Plus (DP), Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603), Dechlorane 604 (Dec 604) and hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), were measured in human milk and maternal serum. Dec 602, Dec 603 and HCDBCO were detected in both sample matrices with detection frequencies over 60%. Dec 604 was not detected in serum and only detected in 4.

In vitro dermal absorption of di(2-ethylhexyl) adipate (DEHA) in a roll-on deodorant using human skin.

In vitro dermal absorption experiments were conducted using a roll-on deodorant that contains 1.56% di(2-ethylhexyl) adipate (DEHA), a plasticizer widely used in consumer products. Human skin specimens were fitted in Bronaugh flow-through Teflon diffusion cells.

Liquid chromatography/tandem mass spectrometry for analysis of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) and 1,2,5,6-tetrabromocyclooctane (TBCO).

Although the two flame retardants 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) and 1,2,5,6-tetrabromocyclooctane (TBCO) have been widely used, a selective instrumental method of analysis for these compounds has not been developed to date. In this study, we demonstrate the feasibility to utilize liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the separation and analysis of α- and β-TBCO and α-, β-, γ-, and δ-TBECH. Acetone was initially used in a tetrahedron solvent system for LC optimization.

Liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry for analysis of Dechloranes.

Liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry (LC/APPI-MS/MS) was investigated as an instrumental method for the analysis of the halogenated norbornene flame retardants, Mirex, Dechloranes 602, 603, 604, and Dechlorane Plus (DP). The LC separation was optimized by screening a variety of stationary and mobile phases, resulting in a short LC separation time of 5 min. Different atmospheric pressure ionization approaches were examined including electrospray ionization, atmospheric pressure chemical ionization, and APPI, each with and without post-column addition.

Liquid chromatography-atmospheric pressure photoionization tandem mass spectrometry for analysis of 36 halogenated flame retardants in fish.

A comprehensive, sensitive and high-throughput liquid chromatography-atmospheric pressure photoionization tandem mass spectrometry (LC-APPI-MS/MS) method has been developed for analysis of 36 halogenated flame retardants (HFRs). Under the optimized LC conditions, all of the HFRs eluted from the LC column within 14min, while maintaining good chromatographic separation for the isomers. Introduction of the pre-heated dopant to the APPI source decreased the background noise fivefold, which enhanced sensitivity.

Development of liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry for analysis of halogenated flame retardants in wastewater.

Until recently, atmospheric pressure photoionization (APPI) has typically been used for the determination of non-polar halogenated flame retardants (HFRs) by liquid chromatography (LC) tandem mass spectrometry. In this study, we demonstrated the feasibility of utilizing liquid chromatography atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (LC-APCI-MS/MS) for analysis of 38 HFRs. This developed method offered three advantages: simplicity, rapidity, and high sensitivity.

Use of simultaneous dual-probe microdialysis for the determination of pesticide residues in a jade plant (Crassula ovata).

A microdialysis application for the sampling of plant pesticide residues has been developed utilizing two probes with differing perfusate rates simultaneously inserted into symmetric components of a sampling system. A simple empirical equation is proposed to calculate analyte concentrations in a semi-solid matrix using two different dialysate concentrations. In vitro application yielded excellent correlations between the calculated and spiked concentrations.

Application of solid-phase microextraction for in vivo laboratory and field sampling of pharmaceuticals in fish.

Previous field studies utilizing solid-phase microextraction (SPME) predominantly focused on volatile and semivolatile compounds in air or water. Earlier in vivo sampling studies utilizing SPME were limited to the liquid matrix (blood). The present study has expanded the SPME technique to semisolid tissues under laboratory and field conditions through the investigation of both theoretical and applied experimental approaches.

Comparison of microdialysis with solid-phase microextraction for in vitro and in vivo studies.

Microdialysis (MD) and solid-phase microextraction (SPME) methods have been developed and compared through in vitro and in vivo studies. For in vitro study, both methods offered accurate and precise results for complex sample matrices by standard addition method. Compared to MD, the fully automated SPME procedure offered several advantages including high-throughput and more efficient sampling, less labor intensity, and capability for batch analysis.

Kinetic calibration using dominant pre-equilibrium desorption for on-site and in vivo sampling by solid-phase microextraction.

A new kinetic calibration was developed using dominant pre-equilibrium desorption by solid-phase microextracton. The calibration was based on isotropism between absorption and desorption, which was proved theoretically and experimentally in an aqueous solution and semisolid matrix. This approach allows for the calibration of absorption using desorption to compensate for matrix effects.