Dermal bioaccessibility of plasticizers in indoor dust and clothing.

Several studies indicate that human exposure to plasticizers via dermal pathway is not negligible, but the dermal bioaccessibility of phthalates and alternative plasticizers from the important environmental matrix including indoor dust and clothing and the importance weight of dermal exposure to those pollutants have been poorly studied. An in vitro physiologically based extraction test was employed to investigate the dermal bioaccessibility of target phthalates and alternative plasticizers from indoor dust and clothing. Temperature, incubation time, sweat/sebum ratio and solid/liquid ratio were selected to study their effects on the bioaccessibility. The bioaccessibility of Diethyl phthalates (DEP), dibutyl phthalate (DBP), bis-2-ethylhexyl phthalate (DEHP), Acetyl tributyl citrate (ATBC), bis-2-ethylhexyladipate (DEHA) and bis-2-ethylhexyl terephthalate (DEHT) in indoor dust were 66.20 ±â€¯1.93%, 94.27 ±â€¯1.31%, 80.37 ±â€¯8.09%, 75.02 ±â€¯2.12%, 94.50 ±â€¯3.42% and 74.09 ±â€¯3.79%, respectively, under the condition of 1:1 sweat/sebum ratio, 1/100 solid/liquid ratio (indoor dust), 1:1 area/area ratio (1:1, clothing) and 90 min incubation time at 36.3 °C which are chosen based on the experimental results and human physical conditions. DBP showed the highest bioaccessibility in all samples. The time course of the plasticizer release was fitted to a first-order one-compartment model. DBP showed the highest release rate (k1) calculated from the model, which was consistent with the bioaccessibility result. Risk assessment indicated that dermal exposure of DBP was an important exposure route, accounting for about 21.58% of total intake, and indoor dust was an important exposure media when considering the dermal bioaccessibility.

A metal nebulizer capillary electrophoresis/Fourier transform infrared spectrometric interface.

A capillary electrophoretic (CE) system has been successfully interfaced to a Fourier transform infrared spectrometer. The advantage of such an interface is that analytes may be detected and often unequivocally identified without analyte derivatization. The interface consists of a stainless steel tube in which the CE capillary is placed and the two are held in contact with the use of a metal tee. A solvent elimination approach is used with the interface, so that analytes are deposited onto an infrared transparent window, that is, CaF2, and measured with the use of an infrared microscope. A critical component of this design is to provide an electrical connection at the end of the CE column to permit stable separations that allow for efficient transport of the sample onto the window. The interface produces an aerosol that is directed at the surface of the infrared transparent window. The use of a volatile electrolyte, along with the flow of helium, allows for partial evaporation of the electrolyte in flight and complete evaporation of the solvent and electrolyte on the surface of the window to produce a "dry", or neat, analyte deposit.