Rodent bait

Two representative examples of single-column SMGPC separations are presented in Figures 2 and 3. The sample for Figure 2 was a rodent bait from which the active ingredient warfarin was to be determined. Quantitation of this component by SMGPC was shown to be as reliable as for the reversed-phase method which is commonly used (35), with the advantage of a several-fold faster sample clean-up U2). 

Under these conditions, warfarin elutes in approximately eight minutes. The minimum detectable quantity of material is approximately 5 ng. Warfarin can be extracted from rodent baits or from field wipe samples using a mixture of dioxane plus 15% water and 1% Nai Oy (27). The extract is injected directly into the HPLC system. Figure 7 is comprised of chromatograms of (a) warfarin standard and (b) an extract of commercial rat bait. 

The presence of abnormal colours may indicate the presence of inorganic pigments (e.g. copper, nickel, or cobalt salts), dyestuffs from tablets, capsules, medicines, pesticides, and rodent baits, especially those containing warfarin, reserpine, chloralose, or diphenadione. Common rat-bait coloms are blue, green, or red and are usually associated wifti oafrneal or cereal grain. 

The concentration of bromethalin in rodent baits is 0.005% or 0.01%. It is effective against rodents that are resistant to anticoagulant rodenticides and does not induce bait shyness. Anorexia and neurological effects occur after an effective dose has been consumed. 

Use of rubber gloves is recommended when handling rodent baits containing this compound. 

Warren [4] showed a determination of warfarin in rodent bait. The bait is of higher molecular mass and is clearly separated from warfarin in a 12-minute analysis on a single Ultrastyragel 100 A column with tetrahydrofuran as solvent. 

Toxicosis is most often the result of accidental ingestion of rodent baits or maiicious baiting of dogs. 

In museums, the placement of rodent bait stations can lead to outbreaks of odd beetles when the bait is based on dried animal food. The presence of dead insects in a museum can contribute to an odd beetle infestation. The vacuuming of floor areas can reduce the number of dead insects and odd beetles. All windows should be... 

Toxicity. Sodium fluoroacetate is one of the most effective all-purpose rodenticides known (18). It is highly toxic to all species of rats tested and can be used either in water solution or in bait preparations. Its absence of objectionable taste and odor and its delayed effects lead to its excellent acceptance by rodents. It is nonvolatile, chemically stable, and not toxic or irritating to the unbroken skin of workers. Rats do not appear to develop any significant tolerance to this compound from nonlethal doses. However, it is extremely dangerous to humans, to common household pets, and to farm animals, and should only be used by experienced personnel. The rodent carcasses should be collected and destroyed since they remain poisonous for a long period of time to any animal that eats them. 

A 17 amino acid long peptide sequentially related to opioid peptides in particular dynorphin A. OFQ/N is inactive at the 5, k, and p opioid receptors, but binds to its own NOP receptor (formerly ORL-1, for opioid receptor like-1). In contrast to opioid peptides, OFQ/N has no direct analgesic properties. OFQ/N is the first example for the discovery of a novel neurotransmitter from tissue extracts by using an orphan receptor as bait. Centrally administered in rodents, OFQ/N exerts anxiolytic properties. OFQ/N agonists and antagonists... 

In contrast to the controlled use of these compounds in the neighborhood of farms and human habitation, they have sometimes been used in a less controlled way against rodents and vertebrate predators, which causes problems in conserved areas. In a number of conserved islands in New Zealand, for example, bait containing brodiphacoum has been used for rodent control, both at bait stations and by aerial distribution (Eason et al. 2002). In the latter case, poisoned bait is freely available, and herbivores and omnivores, as well as predators and scavengers are at high risk. This problem will be discussed further in Section 11.6. 

When ARs have been used to control rodents and vertebrate predators in conserved areas, there have been instances of both primary and secondary poisoning. In New Zealand, such incidents have been observed on islands where bait treated with brodifacoum has been used. Casualties have included native raptors, such as the Australasian harrier (Circus approximans) and morepork (Ninox novaeseelaniae), as well as other species, such as the pukeko. Western weka (Galliralus australis), and... 

Used industrially in poison baits to control rodents, wild pigs, and predators. 

Compound 1080 was also effective against jackrabbits, foxes, and moles. Baits containing 0.05 to 0.1% 1080 on vegetables were used in California to kill jackrabbits (Lepus spp.) and various rodents (Schitoskey 1975). The Arctic fox (Alopex lagopus), intentionally introduced onto the Aleutian Islands in 1835 (Bailey 1993), almost eliminated the Aleutian Canada goose (Branta canadensis leucoparlia) by 1967. 1080-tallow baits were successfully used to control fox populations (Byrd et al. 1988 Tietjen et al. 1988 Bailey 1993). Earthworm baits are used to kill moles. The earthworms are soaked for 45 min in a 2.5% solution of 1080 and placed in mole burrows. The solution can be used several times for additional lots of worms however, the use of the manure worm (Eisenia foetida) should be avoided because it is seldom eaten by moles (Peacock 1964). 

Conspecific secretions and excretions may stimulate pest rodents to consume bait. An example is the metad, or soft-furred rzt, RattusmeltadapalUdior, of the grasslands and crop fields of India. In a laboratory test, 1% conspecific urine from males or females added to the diet of millet increased food consumption by 32 to 70%. The metads also stayed longer in the half of the cage with the urine-treated food than in that with untreated food, and scent marked more there. The males marked with sebum, the females with urine. Male urine tended to be more effective, and males responded more than females (Soni and Prakash, 1987). 

A novel odor for attracting rats or mice to bait is carbon disulfide. It is found in the breath of rats, serves in communication about food, attracts rodents to bait, and increases bait consumption (Bean etal, 1988). Use of carbon disulfide and carbonyl sulfide in baits attracts mice and rats and prevents bait shyness from... 

These materials, as well as more recent poisons like zinc phosphide and fluoroacetic acid, work as acute rodenticides and can be effective when a rodent consumes a lethal quantity of poison in a single dose in its food or drink. Unfortunately, animals often consume less than a lethal dose, which produces side effects which the animals associate with the bait. The result is that they become "bait shy" and are likely to be wary of the same poison bait a second time. 

Very rapidly, a number of other anticoagulants, including the indanediones (4), (Structure 2), were developed as rodenticides. Warfarin first came into wide usage as a rodenticide in 1950 and virtually supplanted all other materials then in use. In the case of all these early materials, multiple bait applications were needed to control rodent populations which, while making the materials safer to use than the available acute poisons, curtailed their use in underdeveloped and less affluent countries because of the large quantities of bait that must be placed to destroy the populations of rodents. 

Once bromethalin had been identified as a compound that was both toxic to rodents at low dose levels and acceptable to them in bait, it was necessary to develop information on its performance under field conditions and to learn more about the mode of action. 

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