Measurements of polybrominated diphenyl ethers and polychlorinated biphenyls in a single drop of blood

Performance and storage integrity of dried blood spots for PCB, BFR and pesticide measurements

“…Contamination can arise throughout the card's lifecycle, e.g., manufacturing, packaging, handling, labeling, transportation, processing, and storage. The sources, types and concentrations of contaminants may vary over time, e.g., an analysis of cards manufactured from 1987 to 2009 showed significant declines of BDE-47, PCB-153 and PCB-194 concentrations, but constant levels of other PBDEs and PCBs [26]. This study reports levels of BDE-47 and PCB-194 on unused cards from 1987 (7,000 and 11,000 ng/L, respectively) that are two to three orders of magnitude higher than measured in the present study.…”

“…However, DBS have been used for other analytes. For example, in mostly pilot studies, human and avian DBS samples were used to measure additional trace metals [15], cotinine [19], perchlorates [20], cysteinyl adducts of benzene oxide [21], bisphenol A [14, 22], and persistent organic compounds, e.g., pesticides [23–25], PCBs [24, 26], PBDEs [9, 24, 26], and fluorinated compounds like PFOS [14, 24, 27, 28]. …”

“…A number of issues in the collection, storage, processing, analysis and use of DBSs have been recognized [7, 10, 12, 13, 18], and most pertain to environmental toxicants. These include: loss of analytes by enzymatic action (or other mechanisms) during the collection, spotting and drying stages [31, 32]; differences between analyte profiles measured using DBS and plasma [33]; effects of storage times and storage conditions on sample integrity [34, 35]; the consistency of blood spot punches and chromatographic considerations on sample cards [36]; variability, recovery, sorption and other issues involved in extracting analytes from sample cards [11, 26, 37]; variability in blood volumes, irregular geometry of the DBS itself, and punch size [8, 38, 39]; background (matrix) contamination on the filter paper [15, 20]; within- and between-lot variability of the sample card properties and contamination [40]; chromatographic, carryover and other separation issues in analysis and quantitation [41]; limited sensitivity of methods, which can be particularly acute given the small volume of sample available [5, 10]; and a lack of standard reference materials (SRMs) to help ensure that measurements meet quality assurance criteria. (For example, SRMs are available from NIST for (persistent) organic contaminants in non-fortified human serum [SRM-1957] and metals in caprine (goat) blood [SRM-955c]).…”

Cryogenic zone compression GC-HRTOFMS for the measurement of PCB-153 and DDE in 20 μL serum samples

“…1 Unlike the methodology recently developed by Lu et al, 2 our method was based on the combination of a miniaturized sample preparation procedure named micro-extraction by packed sorbent (MEPS) with the cryogenic modulation of gas chromatographic peaks for signal enhancement. This modulation process was reported earlier by Patterson et al 3 as cryogenic zone compression (CZC), a specic use of comprehensive two-dimensional gas chromatography (GC Â GC) for ultra-trace level measurements.…”

Dechlorination of polychlorinated biphenyls by iron and its oxides

“…of Chemical Substances and the Toxic Substances Control Act, respectively. However, a large fraction of the PCBs that were produced are still present in the environment (Bert and Esteban, 2008;Lu et al, 2012). From 1930 through to 1970, the cumulative losses of PCBs to the environment were estimated at 354,000 tons (Ackerman et al, 1983 Prior to 1980, the whole amounts of PCBs produced in China were 10,000 tons (MEPPRC, 1991;Chen et al, 2008).…”