Probing new approaches using atmospheric pressure photo ionization for the analysis of brominated flame retardants and their related degradation products by liquid chromatography-mass spectrometry

Atmospheric pressure photo ionisation has been evaluated for the analysis of brominated flame retardants and their related degradation products by LC-MS. Degradation mixtures obtained from the photochemical degradation of tetrabromobisphenol A and decabromodiphenylether were used as model systems for the assessment of the developed methodology. Negative ion mode gave best results for TBBPA and its degradation compounds. [M - H]- ions were formed without the need of using a doping agent. MS and MS/MS experiments allowed the structural identification of new TBBPA "polymeric" degradation compounds formed by attachment of TBBPA moieties and/or their respective cleavage products. In the case of polybromodiphenylethers, the positive mode provided M*+ ions and gave better results for congeners ranging from mono- to pentabromodiphenylethers whereas for higher bromination degrees, the negative ion mode (providing [M - Br + O]- ions) was best suited. Under both positive and negative ionisation modes, the use of toluene as doping agent gave better results. Liquid chromatography-mass spectrometry by means of atmospheric pressure photo-ionisation was applied to the analysis of aromatic brominated flame retardants and their degradation products. This methodology proved to be particularly useful, for the characterisation and structural identification of some compounds which are not amenable to GC-MS, especially in the case of apolar "polymeric" degradation products of tetrabromobisphenol A investigated in this work.     

Optimisation of a selective method for the determination of organophosphorous triesters in outdoor particulate samples by pressurised liquid extraction and large-volume injection gas chromatography–positive chemical ionisation–tandem mass spectrometry

A selective analytical method for the determination of nine organophosphate triesters and triphenylphosphine oxide (TPPO) in outdoor particulate matter is presented. It involves a fully automated pressurised liquid extraction (PLE) step, integrating an alumina clean-up process, and subsequent determination by large-volume injection gas chromatography–positive chemical ionisation–tandem mass spectrometry (LVI-GC–PCI–MS/MS). The extraction variables (solvent, amount of adsorbent, temperature, time and number of cycles) were optimised using a multicriteria strategy which implements a desirability function that maximises both extraction and clean-up efficiencies while searching for the best-compromise PLE conditions. The final method affords quantification limits of between 0.01 and 0.3 μg g⁻¹ and recoveries of >80%, with the exceptions of the most polar analytes, TCEP and TPPO (~65%) for both urban dust and PM10 samples. Moreover, the method permitted the levels of these compounds in dust deposited outdoors (between LOD and 0.5 μg g⁻¹ for TEHP) and PM10 samples (between LOD and 2.4 μg m⁻³ for TiBP) to be measured and reported for the first time. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Instrumental methods and challenges in quantifying polybrominated diphenyl ethers in environmental extracts: a review

Increased interest in the fate, transport and toxicity of polybrominated diphenyl ethers (PBDEs) over the past few years has led to a variety of studies reporting different methods of analysis for these persistent organic pollutants. Because PBDEs encompass a range of vapor pressures, molecular weights and degrees of bromine substitution, various analytical methods can lead to discrimination of some PBDE congeners. Recent improvements in injection techniques and mass spectrometer ionization methods have led to a variety of options to determine PBDEs in environmental samples. The purpose of this paper is therefore to review the available literature describing the advantages and disadvantages in choosing an injection technique, gas chromatography column and detector. Additional discussion is given to the challenges in measuring PBDEs, including potential chromatographic interferences and the lack of commercial standards for higher brominated congeners, which provides difficulties in examining degradation and debromination of BDE congeners, particularly for BDE 209.     

Fast isolation of hydrophobic organic environmental contaminants from exposed semipermeable membrane devices (SPMDs) prior to GC analysis

Semipermeable membrane devices (SPMD) represent a passive sampling technology that is becoming widely used for monitoring of surface waters pollution. While "classic" procedures employ dialysis to recover target compounds from exposed SPMDs, in the present study analytes were isolated from cut membrane together with sequestering medium (triolein) using hexane as an extraction solvent. This approach allowed us to reduce the time needed for accomplishment of isolation step from 48 h to only 1 h. Automated gel permeation chromatography (GPC) clean-up is employed in the following step to separate triolein from analytes fraction. Musk compounds (MCs), polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs) and several other persistent organochlorine compounds (OCs) were determined in the respective fraction by GC method employing selective detectors (MSD, ECD). As shown in a series of analyses of SPMDs deployed in various aquatic ecosystems, high recoveries and good repeatability of results together with a possibility to obtain the information on the pollution of sampling site at the day of sample arrival to laboratory make this newly implemented procedure an interesting alternative to time consuming dialysis.     

The co-pyrolysis of flame retarded high impact polystyrene and polyolefins

The co-pyrolysis of brominated high impact polystyrene (Br-HIPS) with polyolefins using a fixed bed reactor has been investigated, in particular, the effect that different types of brominated aryl compounds and antimony trioxide have on the pyrolysis products. The pyrolysis products were analysed using FT-IR, GC–FID, GC–MS, and GC–ECD. Liquid chromatography was used to separate the oils/waxes so that a more detailed analysis of the aliphatic, aromatic, and polar fractions could be carried out. It was found that interaction occurs between Br-HIPS and polyolefins during co-pyrolysis and that the presence of antimony trioxide influences the pyrolysis mass balance. Analysis of the Br-HIPS + polyolefin co-pyrolysis products showed that the presence of polyolefins led to an increase in the concentration of alkyl and vinyl mono-substituted benzene rings in the pyrolysis oil/wax resulting from Br-HIPS pyrolysis. The presence of Br-HIPS also had an impact on the oil/wax products of polyolefin pyrolysis, particularly on the polyethylene oil/wax composition which converted from being a mixture of 1-alkenes and n-alkanes to mostly n-alkanes. Antimony trioxide had very little impact on the polyolefin wax/oil composition but it did suppress the formation of styrene and alpha-methyl styrene and increase the formation of ethylbenzene and cumene during the pyrolysis of the Br-HIPS.     

凝胶渗透色谱结合气相色谱-负化学源质谱法分析鱼肉及鱼油中的多溴联苯醚和得克隆阻燃剂

建立了凝胶渗透色谱(GPC)结合气相色谱-负化学源质谱(GC-NCI/MS)检测鱼肉及鱼油中8种多溴联苯醚(PBDEs)同系物及2种得克隆阻燃剂(DP)的分析方法。试样中加入内标物BDE-77和13C12-BDE-209后进行索氏提取,提取液经自动GPC系统除脂,多层硅胶层析柱净化后,在15 m长的毛细管气相色谱柱上分离,NCI/MS以选择离子监测方式检测目标化合物。以鱼肉样品为基质,当PBDEs的加标水平为0.2 ng/g和2 ng/g、BDE-209和DP的加标水平相应提高10倍时,其平均加标回收率为71.1%～121.4%,相对标准偏差为2.96%～13.31%(n=5);以信噪比(S/N)为3计算方法的检出限(LOD)为2.2～39.8 ng/kg。用该方法检测市售鱼肉及鱼油样品,其中多溴联苯醚总含量为2.18～15.93 ng/g,以BDE-209、BDE-47为主,两种DP均未检出。该方法准确、灵敏度高,能够满足富含脂质的动物性样品中痕量DP和PBDEs残留的分析要求。     

Chromium complexes bearing disubstituted organophosphate ligands and their use in ethylene polymerization

The crystal structures of three unusual chromium organophosphate complexes have been determined, namely, bis(μ‐butyl 2,6‐di‐tert‐butyl‐4‐methylphenyl hydrogen phosphato‐κO:κO′)di‐μ‐hydroxido‐bis[(butyl 2,6‐di‐tert‐butyl‐4‐methylphenyl hydrogen phosphato‐κO)(butyl 2,6‐di‐tert‐butyl‐4‐methylphenyl phosphato‐κO)chromium](Cr—Cr) heptane disolvate or {Cr₂(μ₂‐OH)₂[μ₂‐PO₂(OBu)(O‐2,6‐^tBu₂‐4‐MeC₆H₂)‐κO:κO′]₂[PO₂(OBu)(O‐2,6‐^tBu₂‐4‐MeC₆H₂)‐κO]₂[HOPO(OBu)(O‐2,6‐^tBu₂‐4‐MeC₆H₂)‐κO]₂}·2C₇H₁₆, [Cr₂(C₁₉H₃₂O₄P)₄(C₁₉H₃₃O₄P)₂(OH)₂]·2C₇H₁₆, denoted ( 1 )·2(heptane), [μ‐bis(2,6‐diisopropylphenyl) phosphato‐1κO:2κO′]bis[bis(2,6‐diisopropylphenyl) phosphato]‐1κO,2κO‐chlorido‐2κCl‐triethanol‐1κ²O,2κO‐di‐μ‐ethanolato‐1κ²O:2κ²O‐dichromium(Cr—Cr) ethanol monosolvate or {Cr₂(μ₂‐OEt)₂[μ₂‐PO₂(O‐2,6‐ⁱPr₂‐C₆H₃)₂‐κO:κO′][PO₂(O‐2,6‐ⁱPr₂‐C₆H₃)₂‐κO]₂Cl(EtOH)₃}·EtOH, [Cr₂(C₂H₅O)₂(C₂₄H₃₄O₄P)₃Cl(C₂H₆O)₃]·C₂H₆O, denoted ( 2 )·EtOH, and di‐μ‐ethanolato‐1κ²O:2κ²O‐bis{[bis(2,6‐diisopropylphenyl) hydrogen phosphato‐κO][bis(2,6‐diisopropylphenyl) phosphato‐κO]chlorido(ethanol‐κO)chromium}(Cr—Cr) benzene disolvate or {Cr₂(μ₂‐OEt)₂[PO₂(O‐2,6‐ⁱPr₂‐C₆H₃)₂‐κO]₂[HOPO(O‐2,6‐ⁱPr₂‐C₆H₃)₂‐κO]₂Cl₂(EtOH)₂}·2C₆H₆, [Cr₂(C₂H₅O)₂(C₂₄H₃₄O₄P)₂(C₂₄H₃₅O₄P)₂Cl₂(C₂H₆O)₂]·2C₆H₆, denoted ( 3 )·2C₆H₆. Complexes ( 1 )–( 3 ) have been synthesized by an exchange reaction between the in‐situ‐generated corresponding lithium or potassium disubstituted phosphates with CrCl₃(H₂O)₆ in ethanol. The subsequent crystallization of ( 1 ) from heptane, ( 2 ) from ethanol and ( 3 ) from an ethanol/benzene mixture allowed us to obtain crystals of ( 1 )·2(heptane), ( 2 )·EtOH and ( 3 )·2C₆H₆, whose structures have the monoclinic P2₁, orthorhombic P2₁2₁2₁ and triclinic P space groups, respectively. All three complexes have binuclear cores with a single Cr—Cr bond, i.e. Cr₂O₆P₂ in ( 1 ), Cr₂PO₄ in ( 2 ) and Cr₂O₂ in ( 3 ), where the Cr atoms are in distorted octahedral environments, formally having 16 ē per Cr atom. The complexes have bridging ligands μ₂‐OH in ( 1 ) or μ₂‐OEt in ( 2 ) and ( 3 ). The organophosphate ligands demonstrate terminal κO coordination modes in ( 1 )–( 3 ) and bridging μ₂‐κO:κO′ coordination modes in ( 1 ) and ( 2 ). All the complexes exhibit hydrogen bonding: two intramolecular O_phos…H—O_phos interactions in ( 1 ) and ( 3 ) form two {H[PO₂(OR)₂]₂} associates; two intramolecular Cl…H—O_Et hydrogen bonds additionally stabilize the Cr₂O₂ core in ( 3 ); two intramolecular O_phos…H—O_Et interactions and two O…H—O intermolecular hydrogen bonds with a noncoordinating ethanol molecule are observed in ( 2 )·EtOH. The presence of both basic ligands (OH^? or OEt^?) and acidic [H(phosphate)₂]^? associates at the same metal centres in ( 1 ) and ( 3 ) is rather unusual. Complexes may serve as precatalysts for ethylene polymerization under mild conditions, providing polyethylene with a small amount of short‐chain branching. The formation of a small amount of α‐olefins has been detected in this reaction.     

Determination of polybrominated diphenyl ethers in indoor dust standard reference materials

Polybrominated diphenyl ethers (PBDEs) have been measured for the first time in three different indoor dust Standard Reference Materials (SRMs) prepared by the National Institute of Standards and Technology (NIST). Two of these, SRM 2583 (Trace Elements in Indoor Dust) and SRM 2584 (Trace Elements in Indoor Dust), have been certified previously for lead and other inorganic constituents. A third, SRM 2585 (Organics in Indoor Dust), is a new indoor dust reference material prepared by NIST which will be certified for various organic compounds (polycyclic aromatic hydrocarbons, pesticides and polychlorinated biphenyls) in 2005 including certified concentrations for 16 individual PBDE congeners and reference values for an additional three PBDE congeners. Dust SRMs were analyzed for 30 PBDE congeners using high-resolution gas chromatography combined with low-resolution mass spectrometry operated in both negative chemical ionization (GC/ECNI–MS) and electron impact ionization (GC/EI–MS) modes. Sensitivity was an order of magnitude higher using GC/ECNI–MS relative to GC/EI–MS. These SRMs have been characterized and compared to the three PBDE commercial products (pentaBDE, octaBDE and decaBDE). PentaBDE and DecaBDE were present in all three SRMs and were the dominant commercial products, making up approximately 33% and 58%, respectively. Recent studies suggest that house dust may be a leading source of human exposure to PBDEs. These SRMs are the first reference materials with certified concentrations for PBDEs, which will aid in validating future measurements of PBDEs in house dust and other similar matrices. Electronic Supplementary Material Supplementary material is available for this article at http://dx.doi.org/ 10.1007/s00216-005-0227-y     

C_(18)膜萃取/液相色谱-质谱联用法测定极地水体中有机磷酸酯

建立了C_(18)膜萃取/液相色谱-质谱联用技术测定极地水体中10种有机磷酸酯(OPEs)的方法。根据优化后的样品前处理及仪器方法,利用C_(18)膜富集4 L水体中的10种OPEs,经二氯甲烷超声提取,在电喷雾正离子模式下,采用选择反应监测(SRM)模式进行分析,线性相关系数为0.994 4~0.999 9。10种OPEs的加标回收率为64.1%~115%,方法检出限为0.08~0.55 ng/L。该方法适用于极地水体中10种OPEs的分析,利用该方法对北极水体样品中的10种OPEs进行检测,测得冰川融水中∑OPEs的质量浓度为0.64~6.64 ng/L,海水中∑OPEs的质量浓度为0.09~2.03 ng/L。     

An analytical multi-residue approach for the determination of semi-volatile organic pollutants in pine needles

Vegetation (and pine needles in particular) has been widely used as an alternative to other conventional sampling devices to assess the atmospheric presence of semi-volatile organic contaminants (SVOCs). While most analytical procedures developed focus only on one or two chemical classes, this this work intends to establish a multi-component protocol to quantify brominated flame-retardants (BFRs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polynuclear aromatic hydrocarbons (PAHs) and one class of contaminant of emerging concern, the synthetic musks fragrances (SMCs). Pine needles extracts were obtained by ultrasonic solvents extraction (USE), and different cleanup approaches using solid-phase extraction (SPE) employing combinations of sorbents and solvents as well as gel permeation chromatography (GPC) were tested. SPE with alumina followed by GCP yielded the best results, with average recoveries over 80%.