Levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in breast milk in Shanghai, China: A temporal upward trend

A validated method for rapid determination of dibenzo-p-dioxins/furans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in human milk: focus on utility of tandem solid phase extraction (SPE) cleanup

“…The mean lipid content of human milk is about 5 % and comparable to that of the common fish. Almost no obvious matrix interferences in 150 human milk samples were observed in our previous PCDD/Fs and DL-PCBs study using ASCS method [8]. These results make it interesting for us to expand and validate the tandem SPE method covering not only PBDEs and PCBs but also PCDDs/Fs in the sample matrix of human milk.…”

“…The procedure of lyophilization, ASE extraction, and defatting was similar to our previous study [8]. Briefly, 40 g of human milk samples were lyophilized (-52°C and 0.03 mbar for 48 h), and then extracted using ASE based on the following conditions: hexane and dichloromethane (1:1, v/ v) as extraction solvents, 100°C of extraction temperature and 1500 psi of extraction pressure.…”

“…These POPs, including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs), marker PCBs (M-PCBs), and polybrominated diphenyl ethers (PBDEs) are generally accumulated in the human body of the general population at ultra-trace levels (pg/g) [4][5][6][7][8][9]. Therefore, in an attempt to achieve a high-sensitive measurement of these POPs for the accurate assessment of their internal exposure risk on the general population, several tens of milliliters (generally Yuanjie Lin and Chao Feng contributed equally to this work.…”

“…40-50 mL) of human milk are normally needed to enrich the target POPs in a highly reduced volume (10-20 μL) [4,8]. Simultaneously, this enrichment will undoubtedly result in large amounts of lipids and other interferences presented at the concentrations several orders of magnitude higher than the analytes [10].…”

“…The traditional sample pretreatment method, based on a Soxhlet extraction and a cleanup through multiple chromatographic columns using silica, acid silica, florisil, and alumina as adsorbents, has limited use because of its well-known disadvantages in manual operation, much time and organic solvent consuming, and large deviations (e.g., QC and measured results) frequently occurred from batch to batch or even from sample to sample in the same batch [10,[14][15][16][17][18][19]]. An integrated method, based on accelerated solvent extraction (ASE) of lyophilized human milk, defatting based on the sulfuric acid silica gel, and cleaning up with a fluid management system (FMS, based on acid multilayer silica, basic alumina, and carbon columns) [4,14,18,20,21], or a FMS liked technique-automate sample clean-up system (ASCS, with the same columns as FMS) [8], has been widely adopted in sample pretreatment with the characters of high effectiveness and automation. However, the cleanup method via FMS or ASCS would use large amounts of solvents to quantitatively recover analytes and remove crosscontamination by washing with extra solvents [14,18,19].…”