Gas chromatographic separation of polychlorinated biphenyls on a new apolar capillary column

Photolytic Transformation Products of Decabromodiphenyl Ethane (DBDPE)

The photolytic transformation of decabromodiphenyl ethane-a current-use brominated flame retardant and major substitute of the structurally related decabromodiphenyl ether-was investigated in different solvents (toluene, dichloromethane, chlorobenzene, and benzyl alcohol). The transformation rate followed pseudo first order kinetics, with increasing half-life ( t_1/2) in the order of toluene ( t_1/2 = 4.6 min), chlorobenzene ( t_1/2 = 14.0 min), dichloromethane ( t_1/2 = 27.9 min), and benzyl alcohol ( t_1/2 ≈ 60 min). Formation and amount of transformation products varied depending on the solvent used. A detailed study of the hydrodebromination products allowed us to tentatively assign all three possible nonaBDPEs (BDPE 207, 208, and in benzyl alcohol only BDPE 206) and three predominant octaBDPE congeners (BDPE 197, 201, and 202). Next to the reported BDPEs, formation of several oxygen containing transformation products (OxyTPs), dominated by octabrominated OxyTP, was verified by GC-Orbitrap-HRMS analysis. Use of HPLC and Florisil column enabled the separation of OxyTPs and BDPEs, and the polybrominated OxyTPs were most likely tricyclic compounds with almost planar structure.

Validation of high-throughput measurement system with microwave-assisted extraction, fully automated sample preparation device, and gas chromatography-electron capture detector for determination of polychlorinated biphenyls in whale blubber

Validation of a high-throughput measurement system with microwave-assisted extraction (MAE), fully automated sample preparation device (SPD), and gas chromatography-electron capture detector (GC-ECD) for the determination of polychlorinated biphenyls (PCBs) in minke whale blubber was performed. PCB congeners accounting for > 95% of the total PCBs burden in blubber were efficiently extracted with a small volume (20 mL) of n-hexane using MAE due to simultaneous saponification and extraction. Further, the crude extract obtained by MAE was rapidly purified and automatically substituted to a small volume (1 mL) of toluene using SPD without using concentrators. Furthermore, the concentration of PCBs in the purified and concentrated solution was accurately determined by GC-ECD. Moreover, the result of accuracy test using a certified material (SRM 1588b; Cod liver oil) showed good agreement with the NIST certified concentration values. In addition, the method quantification limit of total-PCB in whale blubbers was 41 ng g(-1). This new measurement system for PCBs takes only four hours. Consequently, it indicated this method is the most suitable for the monitoring and screening of PCBs in the conservation of the marine ecosystem and safe distribution of foods.

Improved separation of the 209 polychlorinated biphenyl congeners using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry

The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). Four column combinations based on thermally stable phases, DB-1/HT-8, DB-XLB/HT-8, DB-XLB/BPX-50, and HT-8/BPX-50, have been investigated. The HT-8/BPX-50 set produced the best separation. The distribution of the 100 to 150 ms wide peaks was highly structured in the chromatographic space and based on the degree of ortho-substitution within each separated homologue series. A total of 192 congeners were resolved in 146 min (1.3 analyte per min) using this column set. Eight coelutions involved 17 congeners. Among them, seven congeners were present in Aroclors at levels >1.0 wt.% (CBs 33, 47, 48, 95, 97, 163, 187). Except for CBs 47 and 48, none of the major constituents of commercial mixtures were coeluting. CB 138 was well separated from CBs 163 and 164 in the second dimension. For all column sets, CBs 20, 33, and 109 always coeluted with other PCBs. The 12 toxic dioxin-like congeners (CBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189), and the seven European Union marker PCBs (CBs 28, 52, 101, 118, 138, 153, 180) were separated from any interfering congeners. This was not the case for the other investigated column sets.

Recent developments in the high-resolution gas chromatography of polychlorinated biphenyls

The capillary gas chromatography of polychlorinated biphenyls (PCBs) is reviewed. Focus is on the most recent developments in the separation and detection of PCBs rather than sample preparation methods. Included are a comprehensive look at stationary phases that have been used to separate PCBs and the relatively new work on chiral separations of PCBs. Mass spectrometry and atomic emission are presented as selective detection techniques. Suggestions for additional research are proposed where appropriate.

Combined microwave-assisted extraction and gel permeation chromatography for the determination of chlorinated hydrocarbons in seal blubber and cod livers

A fast and effective sample clean-up procedure for the quantitation of chlorinated hydrocarbons in seal blubber and cod livers is presented. Lipophilic sample ingredients are extracted by application of microwave energy. Microwave-assisted extraction (MAE) was performed with ethyl acetate and cyclohexane as solvent. Without exchange of the solvent, the organochlorine compounds are separated from matrix coextractives by gel permeation chromatography. Traces of matrix remainders were separated on deactivated silica prior to GC/ECD analysis. In this study we focused on quantification of PCB 153, PCB 138, PCB 180, HCB, and p,p'-DDE. In seal blubber, the recovery rates for these organochlorines were > 90% for the complete sample clean-up procedure. The standard deviation of the overall-method was within 5%. MAE of cod livers required softer conditions. After optimization of the MAE the organochlorine levels in cod liver were almost identical with those determined with another independent clean-up method.

Enantioselective determination of chiral organochlorine compounds in biota by gas chromatography on modified cyclodextrins

Approaches to the gas chromatographic enantiomer separation of chiral organchlorines (alpha-hexachlorocyclohexane, cis- and trans-chlordane, heptachlor, heptachlorepoxide, oxychlordane, o,p'-DDT, compounds of technical toxaphene and stable atropisomeric polychlorinated biphenyls) are reviewed. Chiral stationary phases based on cyclodextrin derivatives and used for the gas chromatographic enantiomer separation of the chiral organochlorines are described. Enantiomeric ratios of chiral organochlorines in technical mixtures and biological samples are reported and discussed.

Organochlorine residues in marine mammals from the northern hemisphere--a consideration of the composition of organochlorine residues in the blubber of marine mammals

Levels of organochlorines (PCBs, sigma DDT, lindane and its isomers, HCB, chlordane, and toxaphene) were determined in blubber of marine mammals from the northern hemisphere. Differences in both levels and ratios of organochlorine compounds were detected in different species of marine mammals living in the same region, e.g. blubber of harbour seals (Phoca vitulina) accumulated significantly lower levels of lindane, HCB, toxaphene, and DDT and its metabolites than harbour porpoises (Phocoena phocoena). Compared to such elementary differences in the organochlorine pattern in different marine mammals, the influence of age and sex on the results was only minimal. Varying ratios of contaminants in individual harbour porpoises were explained by migration. Constant PCB/DDT ratios were measured in harbour seals. Due to the sedentariness of harbour seals, even local sources of contaminants could be recognized. Careful evaluation of the organochlorine levels and ratios in marine mammals made it possible to monitor the transport of PCBs from the European continent to European Arctic regions.

Current developments in the analysis of water pollution by polychlorinated biphenyls

A review and discussion of the analytical developments of the last 10 years in the determination of polychlorinated biphenyls (PCBs) in water are presented, including sample treatment, clean-up, identification and determination. Some of the most significant advances have occurred in the area of sample preparation, such as the increased adoption of solid-phase extraction and on-line techniques and the chromatographic separation of PCB congeners, principally by mass spectrometry. Special attention is focused on applications to real samples.