No abstract

No abstract

Data presenting the environmental occurrence of ultra-short-chain perfluoroalkyl acids (PFAAs) are scarce and little is known about the potential sources. In this study, ultra-short-chain PFAAs were analyzed in water connected to potential point sources using supercritical fluid chromatography coupled with tandem mass spectrometry. Samples (n = 34) were collected in connection with firefighting training sites, landfills, and a hazardous waste management facility. Ultra-short-chain PFAAs were detected in all samples at concentrations up to 84 000 ng/L (∑C1–C3), representing up to 69% of the concentration of 29 per- and polyfluoroalkyl substances (PFASs). Trifluoroacetic acid (TFA), perfluoropropanoic acid (PFPrA), trifluoromethane sulfonic acid (TFMS), perfluoroethane sulfonic acid (PFEtS), and perfluoropropane sulfonic acid (PFPrS) were detected at concentrations up to 14 000, 53 000, 940, 1700, and 15 000 ng/L, respectively. Principal component analysis suggests that TFA is associated with landfills. PFPrS was associated with samples collected close to the source at all types of sites included in this study. These findings reveal the presence of high concentrations of ultra-short-chain PFAAs released into the environment from various sources and emphasize the large fraction of ultra-short-chain PFAAs to the total concentration of PFASs in water.

No abstract

Abstract. Exposure to some pesticides and persistent organic pollutants (POPs) has been indicated to be a risk factor for non-Hodgkin's lymphoma (NHL). Epstein-Barr virus (EBV) has been associated with some subgroups of NHL. In a previous study we found an interaction between high concentrations of some POPs and titres of antibodies to EBV early antigen (EA IgG) in relation to NHL. In the present study we measured lipid adjusted plasma concentrations of 35 congeners of polychlorinated biphenyls (PCB), p,p'-dichlorodiphenyldichloroethyelene (p,p'-DDE), hexachlorobenzene (HCB), seven subgroups of chlordanes (cisheptachlorepoxide, cis-chlordane, trans-chlordane, oxychlordane, MC6, trans-nonachlordane, cis-nonachlordane) and one polybrominated diphenylether (PBDE) congener (no. 47) in 99 cases with NHL and 99 population based controls. Odds ratios (OR) for NHL were estimated. Sum of PCBs > median in the controls gave odds ratio (OR) 2.0, 95% confidence interval (CI) 0.99-3.9. High sum of chlordanes yielded OR 2.3, 95% CI 1.2-4.5. An interaction with EBV EA IgG was found. High sum of PCB gave OR 5.2, 95% CI 1.9-14 in the group with EA IgG > 40. Similarly HCB yielded OR 5.3, 95% CI 1.9-15, pp'-DDE gave OR 3.3, 95% CI 1.4-7.7 and sum of chlordanes yielded OR 6.8, 95% CI 2.3-20, whereas no association was found with PBDE. In summary, this study confirmed an association between certain POPs and NHL with an interaction with titre of IgG antibody to EBV EA.

No abstract

The use of a new atmospheric-pressure chemical ionization source for gas chromatography (APGC) coupled with a tandem quadrupole mass spectrometry (MS/MS) system, as an alternative to high-resolution mass spectrometry (HRMS), for the determination of PCDDs/PCDFs is described. The potential of using atmospheric-pressure chemical ionization (APCI) coupled to a tandem quadrupole analyzer has been validated for the identification and quantification of dioxins and furans in different complex matrices. The main advantage of using the APCI source is the soft ionization at atmospheric pressure, which results in very limited fragmentation. APCI mass spectra are dominated by the molecular ion cluster, in contrast with the high energy ionization process under electron ionization (EI). The use of the molecular ion as the precursor ion in MS/MS enhances selectivity and, consequently, sensitivity by increasing the signal-to-noise ratios (S/N). For standard solutions of 2,3,7,8-TCDD, injections of 10 fg in the splitless mode on 30-or 60-m-length, 0.25 mm inner diameter (id), and 25 μm film thickness low-polarity capillary columns (DB5MS type), signal-to-noise (S/N) ratios of >10:1 were routinely obtained. Linearity was achieved in the region (correlation coefficient of r 2 > 0.998) for calibration curves ranging from 100 fg/μL to 1000 pg/μL. The results from a wide variety of complex samples, including certified and standard reference materials and samples from several QA/QC studies, which were previously analyzed by EI HRGC/HRMS, were compared with the results from the APGC/MS/MS system. Results between instruments showed good agreement both in individual congeners and toxic equivalence factors (TEQs). The data show that the use of APGC in combination with MS/MS for the analysis of dioxins has the same potential, in terms of sensitivity and selectivity, as the traditional HRMS instrumentation used for this analysis. However, the APCI/MS/MS system, as a benchtop system, is much easier to use.

Ultra-short-chain perfluoroalkyl acids have recently gained attention due to increasing environmental concentrations being observed. The most well-known ultra-short-chain perfluoroalkyl acid is trifluoroacetic acid (TFA) which has been studied since the 1990s. Potential sources and the fate of ultra-short-chain perfluoroalkyl acids other than TFA are not well studied and data reporting their environmental occurrence is scarce. The analytical determination of ultra-short-chain perfluoroalkyl acids is challenging due to their high polarity resulting in low retention using reversed-phase liquid chromatography. Furthermore, recent studies have reported varying extraction recoveries in water samples depending on the water matrix and different methods have been suggested to increase the extraction recovery. The present review gives an overview of the currently used analytical methods and summarizes the findings regarding potential analytical challenges. In addition, the current state of knowledge regarding TFA and other ultra-short-chain perfluoroalkyl acids, namely perfluoropropanoic acid, trifluoromethane sulfonic acid, perfluoroethane sulfonic acid, and perfluoropropane sulfonic acid‚ are reviewed. Both known and potential sources as well as environmental concentrations are summarized and discussed together with their fate and the environmental and human implications.