Interlaboratory Comparison Study on Dioxins in Cow's Milk (original) (raw)
Related papers
Validation and use of the CALUX‐bioassay for the determination of dioxins and PCBs in bovine milk
Food Additives and Contaminants, 1998
There is a strong need for the development of relatively cheap and rapid bioassays for the determination of dioxins and related compounds in food. A newly developed CALUX (Chemical-Activated LUciferase gene expression) bioassay was tested for its possible use to determine low levels of dioxins in bovine milk. Data show that this mammalian cell-based test is very sensitive for 2,3,7,8-substituted dioxins and related PCBs, thereby reflecting the relative potencies of these compounds in comparison to TCDD (TEF-values). The limit of detection was about 50 fg of TCDD. Furthermore, the response obtained with a mixture of dioxins was additive, in accordance with the TEFprinciple. Milk fat was isolated by centrifugation followed by clean-up of the fat with n-pentane, removal of the fat on a 33% H 2 SO 4 silica column, and determination of Ah receptor agonist activity with the CALUX-bioassay. An equivalent of 67 mg fat was tested per experimental unit, resulting in a limit of quantification around 1 pg i-TEQ/g fat. To investigate the performance of the method, butter fat was cleaned and spiked with a mixture of 17 different 2, 3,7,8substituted PCDD and PCDF congeners at 1, 3, 6, 9, 12 and 15 pg TEQ/g fat, as confirmed by GC/MS. In this concentration range, the method showed a recovery of TEQs around 67% (58-87%). The reproducibility, determined in three independent series showed a CV varying between 4% and 54%, with the exception of the sample spiked at 1 pg i-TEQ (CV 97%). The repeatability determined with the sample spiked at 6pg i-TEQ/g showed a CV of 10%. Testing of 22 bovine milk samples, taken at different sites in The Netherlands, in the CALUX-assay showed combined dioxin and dioxin-like PCB levels equivalent to 1.6 pg TCDD/g fat (range 0.2-4.6). GC/MS analysis of these samples revealed an average level of 1.7 pg i-TEQ/g fat, varying between 0.5 and 4.7 pg i-TEQ/g fat. All five samples showing a GC/MS determined dioxin content of more than 2 pg i-TEQ/g fat gave a response in the CALUX-assay corresponding to more than 2 pg TCDD/g fat. These data clearly show that the CA-LUX-bioassay is a promising method for the rapid and low cost screening of dioxins in bovine milk.
Chemosphere, 2010
Quantitative exposure assessment is a useful technique to investigate the risk from contaminants in the food chain. The objective of this study was to develop a probabilistic exposure assessment model for dioxins (PCDD/Fs) and dioxin-like PCBs (DL-PCBs) in pasteurised bovine milk. Mean dioxins and DL-PCBs (non-ortho and mono-ortho PCBs) concentrations (pg WHO-TEQ g À1 ) in bovine milk were estimated as 0.06 ± 0.07 pg WHO-TEQ g À1 for dioxins and 0.08 ± 0.07 pg WHO-TEQ g À1 for DL-PCBs using Monte Carlo simulation. The simulated model estimated mean exposure for dioxins was 0.19 ± 0.29 pg WHO-TEQ kg À1 bw d À1 and 0.14 ± 0.22 pg WHO-TEQ kg À1 bw d À1 and for DL-PCBs was 0.25 ± 0.30 pg WHO-TEQ kg À1 bw d À1 and 0.19 ± 0.22 pg WHO-TEQ kg À1 bw d À1 for men and women, respectively. This study showed that the mean dioxins and DL-PCBs exposure from consumption of pasteurised bovine milk is below the provisional maximum tolerable monthly intake of 70 pg TEQ kg À1 bw month À1 (equivalent of 2.3 pg TEQ kg À1 bw d À1 ) recommended by the Joint FAO/WHO Expert Committee on Food Additives and Contaminants (JECFA). Results from this study also showed that the estimated dioxins and DL-PCBs concentration in pasteurised bovine milk is comparable to those reported in previous studies.
Evaluation of dioxin-like chemicals in pooled human milk samples collected in Australia
Chemosphere, 2007
Design: Human milk samples were collected and analysed for the levels of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and selected dioxin-like polychlorinated biphenyls (PCBs). In total, 157 individual samples collected during 2002 and 2003 as well as 24 samples collected in 1993 were analysed as 20 pools. Results: PCDDs, PCDFs and dioxin-like PCBs were detected in all pooled samples. For samples collected during 2002/2003, the TEQ DFP ranged from 6.0 to 15.2 pg TEQ g À1 lipid with an average of 9.0 pg TEQ g À1 lipid. The average lipid content was 3.7 ± 0.5%. No systematic differences were observed in the levels of PCDDs, PCDFs and PCBs in human milk samples collected from different regions of Australia during 2002/2003. For samples collected in 1993 and analysed as pools, the mean level, expressed as TEQ DFP was 16 ± 1.4 pg TEQ g À1 lipid. The average lipid content was 3.9 ± 0.7%. Conclusion: The levels of PCDDs, PCDFs and dioxin-like PCBs in the human milk of Australian women are both low compared to international levels and similar across all regions of Australia. Consistent with worldwide trends, the levels of PCDDs, PCDFs and dioxin-like PCBs have decreased over a 10 year period from 1993 to 2003 by approximately 40%.
Talanta, 2013
Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast and inexpensive tool for the determination of dioxin-like compounds in a large number of samples and requires only small sample volumes, the use of this technique in human biomonitoring programs provides a good alternative to GC-HRMS. In this study, a new CALUX method for the separate analysis of PCDD/Fs and dioxin-like PCBs (dl-PCBs) in small amounts of human milk samples with the new sensitive H1L7.5c1 cell line was used to analyze 84 human milk samples, collected from mothers residing in the Flemish rural communities. The geometric mean CALUX-Bioanalytical Equivalent (CALUX-BEQ) values, reported for the 84 mothers from the study area were 10.4 (95% CI: 9.4-11.4) pg CALUX-BEQ per gram lipid or 0.41 (95% CI: 0.37-0.45) pg CALUX-BEQ per gram milk for the PCDD/Fs and 1.73 (1.57-1.91) pg CALUX-BEQ per gram lipid or 0.07 (95% CI: 0.06-0.08) pg CALUX-BEQ per gram milk for the dioxin-like PCBs. Multiple regression analysis showed significant associations between PCDD/Fs and weight change after pregnancy, smoking and consumption of local eggs. One pooled human milk sample was analyzed with both CALUX and GC-HRMS. The ratio of CALUX and GC-HRMS results for this sample were respectively 1.60, 0.58 and 1.23 for the PCDD/Fs, the dl-PCBs and the sum of both fractions, when using the 2005-TEF values. Additionally, also low levels of certain brominated dioxins and furans were detected in the pooled sample with GC-HRMS.
Bulletin of Environmental Contamination and Toxicology, 2009
dibenzo-p-dioxin (HpCDD) in milk is presented. Limit of detection (LOD) was found to be 0.002 ng for PeCDD while for other three it was found to be 0.005 ng. Recoveries for PeCDD were checked by spiking the milk at 0.020, 0.050 and 0.10 ng g-1 levels and recovered in the range of 81.03%-120.17%. TCDD, HxCDD and HpCDD were checked at 0.05, 0.10 and 0.5 ng g-1 spiked levels and recovered in the range of 80.47%-133.30%, 88.40%-128.02% and 76.97%-132.55% respectively. Limit of quantification (LOQ) was found to be 0.1 ng g-1 for PeCDD whereas 0.5 ng g-1 for others. %RSD was in the range of 4.30-15.79.
Temporal and local trends of PCDD/F levels in cow’s milk in Switzerland
Chemosphere, 2003
Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were determined in 30 Swiss cowÕs milk samples collected at dairy farms in the vicinity to point sources, in rural/alpine areas distant to known sources, and from tanks in large industrial milk processing plants. The contaminant concentrations in samples collected in 2001 were compared to data from analyses conducted in 1984 and 1990/1991 at the same sites. In 2001, the PCDD/F levels in milk from farms near point sources (0.63 AE 0.26 ng I-TEQ/kg milk fat) are slightly but significantly higher in than milk from remote areas (0.36 AE 0.09 ng I-TEQ/kg milk fat). Consumer milk collected at the processing plants had intermediary levels (0.51 AE 0.19 ng I-TEQ/kg milk fat). However, milk in 2001 was significantly less contaminated than the samples collected in 1990/1991 and 1984. This trend is particularly pronounced near point sources but is also apparent in consumer milk and milk from remote areas. No geographical gradient in the atmospheric input of PCDD/F in Switzerland was found. The reduction in PCDD/F levels in dairy milk is paralleled by and correlated to the remediation of known PCDD/F emitting industries, as enforced by federal authorities.
Determination of polychlorinated dibenzodioxins and dibenzofurans in human milk
Chemosphere, 1986
Background: Currently, release of highly toxic polychlorinated dibenzo-p-dioxins (PCDDs) from combustion processes and industrial activities in the environment, their persistence and bioaccumulation in human attracted more attention and dairy products are among the most important sources of human exposure. This study was aimed to determine the most toxic congeners of dioxins in fresh cow's milk samples collected from the Southwest of Iran. Materials and Methods: 15 composite samples of pasteurized milk from the each of 3 major dairy factories of Khuzestan Province in spring, summer and autumn from July 2011 to March 2012 (3 seasons) were collected. After precipitation of the proteins, fat phase was reduced and extracted with hexane and ether. After dehydration, furans existed in fat percolated with hexane through a column chromatography which contained silica gel/silver nitrate, silica gel, silica gel/sulfuric acid respectively and with percolating output through another column contained activated charcoal and silica gel and washing the lower column with a mixture of dichloromethane-hexane and toluene, concentrated and dissolved in mobile phase and analyzed using HPLC: 150 mm × 4.6 mm ID, 5 µm cosmosil 5 NPE column equipped with a UV detector at 254 and 267 nm, mobile phase:methanol/water (80:20, v/v) at flow rate of 1 ml/min. Results: All samples were found to be contaminated with dioxins comparatively. The concentration of 2, 3, 7, 8 TCDD and 1, 2, 3, 7, 8 PCDD in lipid content (2-3%) were detected in the range of 0.96-3.17 TEQ pg/g and 0.59-2.87 TEQ pg/g respectively. The mean concentrations of dioxins during summer were higher for all factories than other seasons and the lowest content were obtained during winter.
Organohalogen Compounds, 2011
In the first Flemish Environment and Health survey run by the Flemish Centre of Expertise on Environment and Health (FLEHS I 2002(FLEHS I -2006 increased concentrations of PCBs, dioxin-like substances and chlorinated pesticides (a metabolite of DDT and hexachlorobenzene) were observed in cord blood of newborns and in blood of 14-15 year-old adolescents and 50-65 year-old adults living in low populated rural communities of East and West Flanders and Flemish Brabant compared to other Flemish regions. Due to the health concern associated with chlorinated compounds follow-up of pollutant levels in this area is of importance. Therefore, human breast milk from mothers living in these regions was collected (2009-2010) for analysis of different POPs. For the quantification of PCDD/Fs and/or dioxin-like PCBs in (human) milk samples both GC-HRMS and the CALUX bioassay are used in routine analysis. However, most CALUX methods use high amounts of milk (varying between 10 and 60 mL) 1, 2 . Since for the Flemish human breast milk survey in the rural areas not only PCDD/F and dioxin-like PCBs were analyzed, but also other POPs like DDE, PBDEs, marker PCBs, HCB, HCH, perfluorinated compounds, etc., the amount of milk available for the CALUX bioassay was limited. Therefore, a new method was developed for the analysis of PCDD/Fs and dioxin-like PCBs in only 5 mL milk.