Organochlorine pesticides methoxychlor

As indicated in Table VII, 13 of the 18 OCPs were retrieved in excess of 90% recovery during the first extraction. The remaining four OCPs, endrin, endosulfan n, endosulfan sulfate, and methoxychlor were recovered at levels between 10-57%. Since no significant amount of any OCP was recovered during the follow-up extraction, breakdown of some organochlorine pesticides endrin in the injection port of the GC was suspected. 

Two organochlorine pesticides have also been evaluated in animal models using early life stage exposures. Methoxychlor (Chapin et al., 1997) and heptachlor (Smialowicz et al., 2001) were evaluated for immunotoxicity after perinatal plus juvenile exposure of rats. In the case of methoxychlor, T cell-dependent antibody responses were depressed persistently in males but not females (Chapin et al., 1997). For heptachlor, early exposure of Sprague-Dawley rats, using doses relevant to human exposure, produced persistent impairment of antibody responses in males but not females. No adult-exposure immunotoxicity was observed at the doses examined, suggesting that there is an increased susceptibility of the prenatal and/or early postnatal life stages to this pesticide (Smialowicz et al., 2001 Smialowicz, 2002). 

A large number of ubiquitous environmental pollutants are very toxic to the hypothalamic-pituitary-thyroid (HPT) axis when administered at high (greater than environmental) levels. To study low level effects on the HPT axis, laboratory animals were administered a mixture of 16 organochlorine pesticides and other chlorinated hydrocarbons and heavy metals, all at levels similar to those found environmentally, so as to simulate environmental exposure. The chemicals included DDT (6.91), HCB (5.73), TCDD (6.80), PCBs (6.29), methoxychlor (5.08), endosulfan (3.83), heptachlor (6.10), hexachlorocyclohexane (3.80), dieldrin (5.40), aldrin (6.50), mirex (7.18), several chlorinated benzenes (2.84-3.44), cadmium (-1.65), and lead (1.35). Effects were measured by monitoring thyroid activity. The study found that this mixture of environmental pollutants was toxic and can alter HPT physiology in sexually mature malesJ50 ... 

The trace enrichment of pesticides from groundwater is a straightforward problem for reversed-phase SPE. The following example uses the EMPORE disk (C-18) to isolate organochlorine pesticides including aldrin, chlordane, endrin, heptachlor, lindane, methoxychlor, pentachlorophenol, and toxaphene from groundwater (Fig. 4.15). 

At present, the pesticide soil monitoring is carried out by the Ministry of Environment and Waters (MoEW), has started in 1997 and covers the whole country. In the scope of the monitoring programme are the following persistent organochlorine pesticides aldrin, DDT, dieldrin, endrin, heptachlor, hexachlorbenzene (HCB), methoxychlor, cis-heptachlorepo-xide, alfa-HCH and lindane. 

Methoxychlor Pesticide - organochlorine - bioaccumulates - used as a replacement for DDT In the US, 3.7 million pounds manufactured in 1978. Use has declined significantly - regulated has a water contaminant... 

The phenomenal success of DDT stimulated further research, and by 1946 the two DDT analogs, DDD and methoxychlor (Table 1,A) had been produced (Tables are at the end of the chapter). The observation of greater insecticidal activity in those organochlorine compounds that lose their HC1 more easily led to yet another group of chlorinated derivatives, the condensed ring chlorocyclodienes (Table 1,B). Thus, nearly all of the chlorinated pesticides currently in use had been... 

The chlorinated compounds should be completely separated in the order listed in Section 2, with heptachlor nearest the solvent front and dicofol closest to the origin. Other common organochlorine insecticides that can be detected and identified by this TLC procedure include aldrin, DDE, DDT, TDE (DDD), endrin, BHC, daconil, methoxychlor, captan, toxaphene, and chlordane. Alternative mobile phases that should be tested for any particular mixture not separated by hexane-acetone (99 1) include hexane (recommended for aldrin, heptachlor, p,p -DDE, o,p and p,p -DDT and p,p -TDE) benzene-hexane (1 1) and hexane-methanol (99 1) (applicable to more polar pesticides). 

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