Avtor/Urednik		Vrecl, Milka; Uršič, Matjaž; Pogačnik, Azra; Zupančič-Kralj, Lucija; Jan, Janja
Naslov		Excretion pattern of co-planar and non-planar tetra- and hexa-chlorobiphenyls in ovine milk and faeces
Tip		članek
Vir		Toxicol Appl Pharmacol
Vol. in št.		, št. 204
Leto izdaje		2005
Obseg		str. 170-4
Jezik		eng
Abstrakt		This study employed the gas chromatography with electron capture detection to determine residual levels and excretion patterns of two pairs of stmcturally diverse polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 54, 80, 155, and 169) administered to lactating sheep by intramuscular injection. PCB levels and excretion pattems in blood, milk, and faeces were time-dependent and differed from the composition of PCB congeners administered. Lactational transfer substantially exceeded the faecal transfer. Between days 3 and 7, the amount of PCB congeners 54 and 169 excreted in milk was around 50- and 800-fold higher than the amount of these two congeners excreted via faeces. During the same period, the relative contribution of co-planar PCB congeners (80 and 169) in PCB pattern decreased in blood and increased in milk and faeces compared with non-planar PCBs (54 and 155). On day 3, the ratio PCB 169 to 54 was 7-fold higher in milk than in faeces. PCB congeners with log KoW values under 6.5 reached peaks of their excretion in milk within the first three days after administration, while the super-lipophilic PCB 169 congener with log Kow value of over 7 has not reached the plateau until day 10, but afterwards, its level remained relatively high throughout the observation period. During the 57-day follow-up period, the excretion of PCB 80, 155, and 169 in milk was 4.5-, 14-, and 46-fold greater compared with PCB 54. Differences in levels and patterns were explained with some physicochemical properties of individual PCB congeners, such as lipophilicity, planarity, metabolic stability, sorption/diffusion properties.
Deskriptorji		MILK POLYCHLORINATED BIPHENYLS FECES SHEEP TIME FACTORS INJECTIONS, INTRAMUSCULAR CHROMATOGRAPHY, GAS