Gas Chromatography-high Resolution Mass Spectrometry Research Articles

Simultaneous determination of three alternative flame retardants (dechlorane plus, 1,2-bis(2,4,6-tribromophenoxy) ethane, and decabromodiphenyl ethane) in soils by gas chromatography–high resolution mass spectrometry

A gas chromatography–high resolution mass spectrometry (GC–HRMS) method has been developed for the simultaneous determination of three alternative flame retardants, dechlorane plus (DP), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and decabromodiphenyl ethane (DBDPE) in soils. The soil samples were extracted by accelerated solvent extraction, followed by purification with concentrated sulfuric acid partitioning combined with acid–base silica gel column separation. The gas chromatography featured with a thermostable capillary column of short length and a thin stationary phase was operated in pulse injection mode. A double-focusing magnetic sector high resolution mass spectrometer with electron impact ionization was used for quantification of the analytes. The method detection limits were 0.27–0.33pg for DPs, 0.41pg for BTBPE, and 36pg for DBDPE. The mean recoveries for DPs, BTBPE, and DBDPE in spiked soils were 88–107%, 78–97%, and 74–113%, respectively, with relative standard deviations ranging from 5.2% to 18%. The recoveries of 13C-labeled standards for DPs, BTBPE, and DBDPE in soil samples were 45–110%, 67–118%, and 27–82%, respectively. These results met the acceptable range of labeled standards for analysis of polybrominated diphenyl ethers as specified by the USEPA 1614 method.

A sensitive, rapid, and simple DR-EcoScreen bioassay for the determination of PCDD/Fs and dioxin-like PCBs in environmental and food samples.

In developing countries in Asia, such as China, Vietnam, and Thailand, there is a strong need for the development of relatively rapid and low-cost bioassays for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in environmental and food samples. These compounds are known to induce a variety of toxic and biological effects through their ligand-specific binding of the aryl hydrocarbon receptor (AhR). Indeed, several AhR-mediated reporter gene assays are widely used as prescreening tools for high-resolution gas chromatography/high-resolution mass spectrometry (HRGC-HRMS) analysis, which individually measures 17 PCDD/Fs and 12 DL-PCBs. In 2008, we have developed a new sensitive and rapid reporter gene assay using a genetically engineered stable cell line, designated DR-EcoScreen cells. The DR-EcoScreen assay using these cells has a number of great advantages of its sensitivity to 2,3,7,8-tetrachlorodibenzo-p-dioxin and its simple procedure, which shows little variance in the data (within CV 10%) compared to other reporter gene assays. In this review, we summarize the application of the DR-EcoScreen assay to the determination of PCDD/Fs and DL-PCBs in ambient air samples, in fish and shellfish samples, and in flue gas samples from incinerators and provide potential usefulness of this bioassay for the determination of PCDD/Fs and DL-PCBs in various matrices.

Analysis of all 209 polychlorinated biphenyl (PCB) congeners (with special reference to dioxin-like PCB congeners) in Japanese seabass and related species by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS)

We subjected edible parts of Lateolabrax japonicus and three related species collected from western Japan in the period 2007–2012 to congener-specific concentration analysis of PCBs using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). Σ PCBs ranged from 1 ng/g wet wt in Lateolabrax sp. A aquacultured in Ehime to 80 ng/g wet wt in L. japonicus from Hyogo (facing the Seto Inland Sea). Although eutrophication of the Seto Inland Sea is almost homogeneous, high Σ PCB concentrations were restricted to the eastern sector. In most of the fish, penta- to hepta-chlorinated congeners were dominant. The low Σ PCB concentrations measured in aquacultured seabass from Ehime might be related to the provision of low-contaminant feeds. The toxic equivalent (TEQ) of dioxin-like PCBs ranged from <0.1 to 1.4 pg/g wet wt, values that are within the “safe levels for human-consumption criteria” used by the Japanese government.

Identification of non-host semiochemicals for the brown dog tick, Rhipicephalus sanguineus sensu lato (Acari: Ixodidae), from tick-resistant beagles, Canis lupus familiaris

Studies have shown that the brown dog tick, Rhipicephalus sanguineus sensu lato, when fed on the beagle breed of dog, Canis lupus familiaris, development negatively affected in comparison with tick development after feeding on the English cocker spaniel breed. Thus leading to the suggestion that beagle dogs are be tick-resistant dogs. Behavioural studies have demonstrated that more ticks are attracted by extracts from cocker spaniels than from beagles and that the odour of beagles is a repellent. To test the hypothesis that resistant hosts produce repellent compounds, we undertook comparative chemical analysis on beagle odour and cocker spaniel extracts using coupled high-resolution gas chromatography–mass spectrometry (GC–MS) and also used Petri-dish and olfactometer behavioural assays to assess the response of ticks to identified non-host compounds. The beagle odour extracts contained almost three times as many chemical compounds as cocker spaniel samples. Several non-host compounds were identified, i.e. 2-hexanone, benzaldehyde, nonane, decane and undecane. In Petri-dish assays, 2-hexanone was repellent at 30min at concentrations of 0.200 and 0.050mgcm−2, whilst at 10min, the 0.100mgcm−2 concentration was repellent. Benzaldehyde repelled ticks at 30min (0.200mgcm−2) and at 5min (0.050mgcm−2). Undecane was repellent for R. sanguineus s.l. ticks for the first 5min at the highest concentration tested. Nonane and decane did not show any significant repellency at any concentration or time evaluated. When 2-hexanone and benzaldehyde were combined, an increase in the repellency rate was observed, with activity comparable or better than N,N-diethyl-3-methylbenzamide (DEET). In olfactometer bioassays, a 1:1 mixture of 2-hexanone:benzaldehyde and DEET were repellent for R. sanguineus s.l. adults at the concentration of 0.200mgcm−2. This study identified non-host semiochemicals that mediate avoidance of the beagle dog breed by R. sanguineus s.l. This finding may enable development of new approaches to control this tick.

Investigation of photo-assisted and crude peroxidase mediated transformations of chlorinated phenols (CPs) from spiked and industrial wastewaters: identification of reaction products.

This work focused on photo-assisted crude peroxidase mediated transformations of chlorinated phenols (CPs) from spiked and industrial wastewaters and the identification of reaction products formed. Garden radish Raphanus sativus was the source of crude peroxidase. No chlorine bearing compounds were detected by gas chromatography-high resolution mass spectrometry analysis. Under identical test conditions, the concentrations of 4-chlorophenol and 2,4-dichlorophenol were demoted to zero from 514 mg/L, 652 mg/L and that of 2,4,6-trichlorophenol and pentachlorophenol were reduced to 18 mg/L and 37 mg/L from 790 mg/L and 1066 mg/L, respectively (high-pressure liquid chromatography analysis). Chloride ion release profiles also showed a progressively increasing trend. A neat chemical oxygen demand removal to the extent of 63-79% was achieved in the case of spiked wastewater sample and to the extent of 77% for industrial wastewaters. A hypothesis reaction scheme was also suggested to comprehend the mechanism of degradation reactions.

Reliable and sensitive adenovirus-based reporter system for high-throughput screening of dioxins

Dioxin-responsive element (DRE)-driven luciferase reporter assay is a rapid and cost-effective screening method for detection and semi-quantitation of dioxins and dioxin-like chemicals in samples from a variety of matrices. However, most of such stable cell lines gradually lose their dioxin responsiveness over time, possibly due to cellular degradation and/or silence of the transfected reporter gene. The study aimed to establish a recombinant adenovirus-based DRE-driven luciferase reporter system for easy maintenance and improvement of dioxin sensitivity/responsiveness. Both the Ad-4xDR adenovirus-based and the Huh7-4xDRE-Luc cell-based reporter systems carry a luciferase reporter gene driven by the same 4xDRE-TATA cassette, i.e., 4 copies of DRE and a TATA box. Comparison of the two reporter systems indicated that the adenovirus-based system was much more sensitive and responsive to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) than the cell-based system. Among the four recombinant adenoviruses, Ad-4xDR, Ad-6xDR, Ad-9xDR, and Ad-15xDR carrying 4, 6, 9, and 15 copies of DRE, respectively, the Ad-6xDR-infected H4IIE cells showed the highest TCDD responsiveness. Following optimization of assay conditions, including temperature, dimethyl sulfoxide (DMSO) concentration, and multiplicity of infection (MOI) of adenovirus, the Ad-6xDR-based system exhibited markedly superior performance in TCDD sensitivity (limit of detection (LOD) = 0.02 pM) and responsiveness (the half maximal effective concentration (EC50)=10.41 pM and a maximum of 409.34 folds of luciferase induction at 300 pM TCDD). Analysis of soil samples showed a high correlation between the Ad-6xDR-based reporter assay and high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The study reveals that, as compared with our previous cell-based system, the Ad-6xDR-based reporter system is more reliable and sensitive for high-throughput screening of dioxins.

Concentrations and distributions of 18 organochlorine pesticides listed in the Stockholm Convention in surface sediments from the Liaohe River basin, China

Organochlorine pesticides (OCPs) were analyzed in 26 surface sediment samples from the Liaohe River basin, and the distributions of and potential environmental risks posed by OCPs in the basin were evaluated. Eighteen OCPs listed in the Stockholm Convention were determined using isotope-dilution gas chromatography–high resolution mass spectrometry. This is the first study of hexachlorobenzene (HCB) in the Liaohe River basin sediments. The total OCP concentrations were 0.39–68.06 ng g−1 dry weight. The total α-, β-, γ-, and δ-hexachlorocyclohexane (HCH), the total dichlorodiphenyltrichloroethane (DDT – p,p′-dichlorodiphenyldichloroethane (DDD), p,p′-dichlorodiphenyldichloroethylene (DDE), o,p'-DDT, and p,p′-DDT), and the HCB concentrations in the sediment samples were 0.1–28.48 ng g−1 (mean 4.01 ng g−1), 0.08–6.52 ng g−1 (mean 3.07 ng g−1), and 0.18–24.8 ng g−1 (mean 4.38 ng g−1), respectively. The HCB concentrations were higher than the concentrations of the other OCPs, and the HCHs and HCB together were the dominant OCPs. β-HCH was the most abundant HCH isomer. The concentrations of DDTs and other OCPs were relatively low, and the (DDE+DDD)/DDT ratios (>0.5) and DDD/DDE ratios (<1) indicated that no recent DDT inputs had occurred in the Liaohe River system. The main sources of HCHs were probably the historical production and agricultural use of HCH in the study area. The DDT and HCH concentrations were generally below or similar to the concentrations that have been found in other parts of the world. An ecotoxicological evaluation indicated that HCHs in surface sediments pose slight risks to human and ecological health in the Liaohe River basin.

Non-targeted analysis of electronics waste by comprehensive two-dimensional gas chromatography combined with high-resolution mass spectrometry: Using accurate mass information and mass defect analysis to explore the data

Comprehensive two-dimensional gas chromatography (GC×GC) and high-resolution mass spectrometry (HRMS) offer the best possible separation of their respective techniques. Recent commercialization of combined GC×GC–HRMS systems offers new possibilities for the analysis of complex mixtures. However, such experiments yield enormous data sets that require new informatics tools to facilitate the interpretation of the rich information content.This study reports on the analysis of dust obtained from an electronics recycling facility by using GC×GC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. New software tools for (non-traditional) Kendrick mass defect analysis were developed in this research and greatly aided in the identification of compounds containing chlorine and bromine, elements that feature in most persistent organic pollutants (POPs). In essence, the mass defect plot serves as a visual aid from which halogenated compounds are recognizable on the basis of their mass defect and isotope patterns. Mass chromatograms were generated based on specific ions identified in the plots as well as region of the plot predominantly occupied by halogenated contaminants. Tentative identification was aided by database searches, complementary electron-capture negative ionization experiments and elemental composition determinations from the exact mass data. These included known and emerging flame retardants, such as polybrominated diphenyl ethers (PBDEs), hexabromobenzene, tetrabromo bisphenol A and tris (1-chloro-2-propyl) phosphate (TCPP), as well as other legacy contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated terphenyls (PCTs).

Levels and Congener Profiles of PBDEs in Edible Baltic, Freshwater, and Farmed Fish in Finland

Fish is the major source of polybrominated diphenyl ethers (PBDEs) for Finnish consumers. To estimate the PBDE contamination in fish that Finns regularly consume as food, a large-scale sampling was undertaken in 2009-2010. Altogether 207 samples of 17 edible fish species were collected from commercially and recreationally important fishing areas in the Baltic Sea, freshwater lakes, and farming facilities. The analysis of 15 PBDE congeners was performed in an accredited testing laboratory with high-resolution gas chromatography mass spectrometry. In all of the samples, the Σ15PBDE varied between 0.029 and 73 ng/g fw. The most abundant congeners were BDE-47 (average proportion 42%), -99 (8.4%), -100 (11%), -154 (5.6%), and -209 (27%). High levels of BDE-209 were observed in the Baltic Sea, off the coast of Pori, in Baltic herring, perch, pike, and pike-perch. Overall, the PBDE levels in Baltic and freshwater fish were low. The levels in farmed whitefish were slightly higher than in wild whitefish. The reasons for the high BDE-209 levels in Baltic herring in Pori and the elevated levels of PBDEs in farmed whitefish should be investigated more thoroughly.

Blood levels of polychlorinated biphenlys and organochlorinated pesticides in women from Istanbul, Turkey.

The human body is not a chemically uncontaminated system. Every simple action that humans undertake, such as drinking water, eating, nursing, and even breathing air, puts the system under environmental xenobiotic exposure stress. Environmental chemicals have been shown to produce unwanted effects on health and remove the right to healthy living, starting from the first encounter in utero to geriatrics, throughout the lifespan. Organochlorine pesticides (OCPs) and polychlorinated biphenyl (PCB) levels, important members of the persistent organic pollutants (POPs), have been detected before in human breast milk and also in the adipose tissue of women from different regions of Turkey; however, there was no information about the blood levels of these chemicals. This study generated the first information that evaluates OCP and PCB contamination levels in the blood of the women living in Turkey. The current study measured the blood concentrations of OCPs and PCBs in 58 healthy women (age 20-41 years; mean age 28 years) who were living in Istanbul, Turkey, in the years 2010-2012. Samples were analyzed for 29 OCPs and 18 PCB congeners using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). PCB 153 was the predominant congener (643.2 pg/g lipid), followed by PCB 138 and PCB 180. 4,4'-DDE (24872.8 pg/g lipid) was the most common organochlorinated pesticide contaminant in studied blood samples. Results for analyzed chlorinated compounds were as follows: ∑PCB 2682 ± 3300 pg/g lipid; ∑DDT 25,938 ± 28,644 pg/g lipid; and ∑HCH 2930 ± 2222 pg/g lipid, respectively. The mean concentration of ∑WHOPCB-TEQ was 0.037 pg/g on a lipid basis. This information will be important base data during the assessment of the general health concerns of women, as well as for studies about how endocrine disruptors affect humans for forthcoming studies.

Polychlorinated naphthalene concentrations and profiles in cheese and butter, and comparisons with polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran and polychlorinated biphenyl concentrations

Polychlorinated naphthalenes (PCNs) are candidates for inclusion in the Stockholm Convention on persistent organic pollutants. PCNs are structurally and toxicologically similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and its analogues. Intake in food is considered to be an important human exposure pathway for PCNs. In this preliminary study, cheese and butter samples were analysed for PCNs, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) using an isotope dilution gas chromatography high-resolution mass spectrometry method. The aim of this study was to evaluate the PCN concentrations in the cheese and butter samples and to compare them with the PCDD, PCDF and PCB concentrations. The PCN concentrations were 5.6–103 pg g−1 of wet weight in the seven cheese samples tested and 5.0–199 pg g−1 of wet weight in the seven butter samples tested. The mass concentrations of lower chlorinated congeners were greater than those of the higher chlorinated congeners. Congeners of CN45/36, CN27/30 and CN33/34/37 were much more abundant than other congeners found in tetrachlorinated PCNs. Congeners of CN51, CN66/67 and CN73 were determined to be the predominant congeners in penta-, hexa- and heptachlorinated homologs, respectively. The PCNs contributed around 5% of the total PCN, PCDD, PCDF and PCB toxic equivalence (TEQ) values. CN73 was found to be the dominant PCN congener and contributed more than 40% to the PCN TEQ value. Congeners CN66/67, CN69 and CN63 were also found at relatively high levels. The PCB congener CB118 was the predominant congener (by mass-based concentration) of the 12 dioxin-like PCBs (dl-PCBs). The PCBs contributed 53.8% of the total TEQ, and congener CB126 contributed more than any other compound that was analysed to the total TEQ. The PCDDs and PCDFs contributed 11.6% and 29.7% of the total TEQ values, respectively.

Effective evaluation of catalytic deoxygenation for in situ catalytic fast pyrolysis using gas chromatography–high resolution mass spectrometry

Effective deoxygenation in catalytic fast pyrolysis (CFP) is crucial for bio-oil stabilization and its successful commercialization. Herein, we utilize a new analytical platform that couples gas chromatography (GC) to dopant-assisted atmospheric pressure chemical ionization (dAPCI) time-of-flight mass spectrometry (TOF MS) to evaluate catalytic deoxygenation of cellulose pyrolysis. Soft ionization and accurate mass measurement through dAPCI-TOF MS allows direct chemical composition analysis of GC-separated molecules, regardless of their presence in the database. The analytical approach was successfully demonstrated for its ability to evaluate catalytic efficiency of different catalysts and to monitor the change in CFP reaction products with catalyst-to-biomass load ratio. A total of 142 compounds could be analyzed with this approach compared to 38 compounds in traditional Py-GC-EI-MS analysis.

Study on the mass fragmentation pathway of the synthetic cannabinoids JWH-018 and JWH-073

Two potent synthetic cannabinoid receptor agonists, JHW-018 and JWH-073, were recently detected as some of the most prominent active agents in abusively used incenses such as ‘spice’ and other herbal blends. Many countries took legal action to ban or control these substances and some of its analogues, and also the world Anti-Doping Agency prohibited them in elite sports during competition. However, few mass spectrometric fragmentation pathway studies of these compounds exist using a high-resolution mass spectrometer and lack of an assigned fragmentation pathway hindering attempts to detect them. Therefore, there is an urgent need to research the synthetic cannabinoid receptor agonist fragmentation pathways. In this study, we studied the fragmentation pathways of two types of synthetic cannabinoid receptor agonists (JWH-018 and JWH-073) using Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS) and Gas Chromatography-High Resolution Mass Spectrometry (GC-HRMS). The accurate ion masses from the GC-HRMS and the product ions from the GC-MS/MS were combined and used to obtain the MS fragmentation pathways for these compounds. Most ions were assigned according to the collected high-resolution accurate mass data, and we proposed typical fragmentation pathways of the two types of synthetic cannabinoid receptor agonists. Furthermore, a series of characteristic ions, such as m/z 324, 254, 270, and 241, were explained for the first time. These findings are valuable for identifying synthetic cannabinoid receptor agonists and could also provide a theoretical basis for pharmaceutical and metabolites analysis.

Combinatorial biochemical and chemical analyses of polychlorinated dibenzo-p-dioxins and dibenzofurans in agricultural soils from Chongming Island, Shanghai, China.

We compared polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations [expressed as toxic equivalent quantities (TEQs)] in agricultural soil samples from Chongming Island (Shanghai, China) determined using two analytical approaches, an enzyme-linked immunoassay (EIA) method and a high resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) method. The PCDD/F concentrations in all 31 soil samples were at background levels (7.30-16.7pg EIA-TEQ/g from the EIA analysis and 0.526-1.99pg WHO-TEQ/g from the HRGC/HRMS analysis). Although, the EIA method overestimated the PCDD/F concentrations compared with the concentrations determined using the HRGC/HRMS method. The absence of false-negatives showed by the EIA analysis verified that this method is useful for preliminary sample screening (prior to HRGC/HRMS analysis) and the preliminary characterization of potentially contaminated sites.

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polybrominated diphenyl ethers in sediments and fish species from the Murchison Bay of Lake Victoria, Uganda

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polybrominated diphenyl ethers (PBDEs) were analyzed in sediments and fish from the Murchison Bay of Lake Victoria by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Average concentrations of total (Σ) PCDD/Fs and ΣPBDEs in sediments ranged from 68.8 to 479pgg−1 dry weight (dw) and 60.8 to 179pgg−1 dw, respectively. Contamination levels of sedimentary PCDD/Fs and PBDEs were low to moderate compared to other urbanized regions worldwide. The concentrations in different fish species (Nile perch; Lates niloticus and Nile tilapia; Oreochromis niloticus) were 5.32 to 49.0pgg−1 wet weight (ww) for PCDD/Fs and 59.3 to 495pgg−1 ww for PBDEs. Higher concentrations of the pollutants were found in L. niloticus than O. niloticus, which could be attributed to species differences in feeding habits and lifestyles. World Health Organization-toxic equivalents (WHO2005-TEQs) for PCDD/Fs ranged from 0.08 to 0.33pgTEQg−1 dw and 0.001–0.14pgTEQg−1 ww in sediments and fish, respectively. The TEQ values were low compared to the data for fresh water fish reported in literature and within a permissible level of 3.5pgg−1 ww recommended by the European Commission. Based on the Commission set value and minimum risk level criteria formulated by the Agency for Toxic Substances and Disease Registry, the fish from the Murchison Bay was fit for human consumption.

Identification of black market products and potential doping agents in Germany 2010-2013.

The desire to increase the athletic performance, to 'optimize' an individual's appearance, and to complement but also to arguably substitute exercise by means of drugs and drug candidates has generated a considerable (illicit) market for compounds such as anabolic-androgenic steroids, stimulants, growth promoting peptide hormones, and so on. Genuinely developed for therapeutic use, their abuse/misuse generates enormous health risks, which has necessitated comprehensive controls of compound trafficking by customs and anti-doping authorities. From 2012 to 2013, the Bureau of Customs Investigation confiscated products containing anabolic-androgenic steroids (AAS; 259 kg), stimulants (13 kg), selective estrogen receptor modulators (SERMs; 24 kg), and human growth hormone (hGH; 3500 ampules). In cooperation with the Bureau and under the umbrella of the European Monitoring Center for Emerging Doping Agents (EuMoCEDA), the Cologne Anti-Doping Laboratory analyzed an additional 337 (black market) products between 2010 and 2013, allowing to monitor developments in drug use and, hence, the anticipation of new challenges in sports drug testing. Main tools utilized in characterizing confiscated materials were liquid chromatography-high resolution mass spectrometry (LC-HRMS), gas chromatography-high resolution mass spectrometry (GC-HRMS), and polyacrylamide gel electrophoresis (PAGE) with subsequent bottom-up identification of peptidic compounds using nano liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS). Among the 337 substances analyzed in the doping control laboratory in Cologne, 67 active ingredients were found, 49 of which being categorized as doping agents by the World Anti-Doping Agency (WADA). A total of 83.7 % accounted for steroidal substances (predominantly testosterone, trenbolone, and nandrolone and corresponding esters), 12.8 % accounted for peptide hormones and growth factors (predominantly hGH and growth hormone releasing peptides (GHRPs)), 3.2 % of the products contained hormones and metabolic modulators, and 0.3 % accounted for diuretic agents. Outstanding findings were the detection of the selective androgen receptor modulator (SARM) LGD-4033, the thymic hormone thymosin β4, and a fusion protein of unknown biological activity. Trafficking of considerable amounts of arguably performance and/or body-enhancing compounds has been observed during the past 4 years, the majority of which is categorized as relevant to sports drug testing. Several substances are of fake/non-approved nature and represent enormous health risks to the 'customer'.

Strong Associations Between the Pesticide Hexachlorocyclohexane and Type 2 Diabetes in Saudi Adults

Pesticide exposure has been implicated as an environmental risk factor for the development of type 2 diabetes mellitus (T2DM). The aim of this study was to investigate the association of the body burden of the pesticide hexachlorocyclohexane (HCH) with the risk of T2DM in a sample of adults from Saudi Arabia. Serum samples were obtained from 280 adult subjects. Hexachlorocyclohexane isomer residues were measured by high-resolution gas chromatography-mass spectrometry. Data on lifestyle, dietary habits, and health status were gathered. Associations between exposure and T2DM were analyzed by logistic regression. Around 49% of adults enrolled in this study were diagnosed with T2DM. Among various HCH isomers, serum concentrations of the pesticides β and γ-HCH were most strongly and consistently linked to T2DM in our studied subjects. Associations of HCH varied across five components of the metabolic syndrome. It positively and significantly associated with four out of the five components, especially elevated triglycerides, high fasting glucose, high blood pressure and HOMA-IR but negatively and significantly with HDL-cholesterol. This study in line with earlier ones about diabetes associated with HCH pesticide exposure and proposes possible hormonal pathways worthy of further investigation.

Analysis of polychlorinated biphenyls and organochlorine pesticides in archived dried blood spots and its application to track temporal trends of environmental chemicals in newborns

Dried blood spots (DBS) collected from infants shortly after birth for the newborn screening program (NSP) in the United States are valuable resources for the assessment of exposure to environmental chemicals in newborns. The NSP was debuted as a public health program in the United States in the 1960s; and the DBS samples collected over a period of time can be used in tracking temporal trends in exposure to environmental chemicals by newborns. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in DBS samples collected from newborns in Upstate New York from 1997 to 2011 by gas chromatography–high resolution mass spectrometry (GC–HRMS). Twelve PCBs and two OCPs were found in DBS samples at a detection rate above 50% (n=51). The mean whole blood concentration of ΣPCBs (sum of 12 congeners) over the 15-year period was 1.06ng/mL, followed by p,p′-DDE (0.421ng/mL) and HCB (0.065ng/mL). The measured concentrations of PCBs and p,p′-DDE in infants׳ blood were comparable to those reported in cord blood, suggesting maternal/trans-placental transfer of these compounds from mothers to fetuses. The concentrations of ΣPCBs and p,p′-DDE in blood samples of infants decreased significantly between 1997 and 2001, and no significant reduction was found thereafter. This observation is consistent with the trends reported for these chemicals in other human tissues in the United States.

Dioxins in the semen of men with infertility.

The purpose of the present study was to assess ejaculate contamination by polychlorinated dibenzo-p-dioxins/furans in male infertility. The database of 168 infertile and 49 fertile men was included in the study. Dioxin content was determined using gas chromatography/high-resolution mass spectrometry (GC/HRMS). In the ejaculate of infertile men, the content of dioxins and furans was 2.2-2.3 times higher than in fertile donors. The maximum level of the most toxic dioxin congener was detected in pathospermia. Contamination of semen of infertile men by polychlorinated dibenzo-p-dioxins/furans supports the hypothesis about the relationship between environmental factors and reproductive health.

Effect of column bleed on trueness of high-resolution mass spectrometric determination of dibenzo-p-dioxins, dibenzofuranes, and polychlorinated biphenyls

Summary Effect of column bleed on trueness of determination of trace levels of dibenzofuranes (PCDD/F) and biphenyls (PCB) by gas chromatography-high-resolution mass spectrometry (GC-HRMS) was studied. As a result of extensive bleed of an arylenesiloxane capillary column, fluctuations of abundance ratios of monitored ions were observed, making exact determination of target analytes impossible. These effects were observed on food samples as well as on pure standard mixtures. The column bleed affected the abundance ratios of PCDD/F and PCB within the range of 13–328 pg of target analyte/mL, and higher levels of analytes remained intact. An analysis of diluted calibration mixtures is recommended as a tool for detection of column bleed.