Residue detectable

Eddy current devices for detecting residual austenite comprise ... 

Pubhc concerns about pesticides in the diet of infants and children resulted in an expert committee convened by the U.S. National Academy of Sciences which devoted four years to the review of all available data. A consensus report was issued in 1993 (80). A number of recommendations for further work to more precisely define what constitutes the diet of infants and children were made. No risk could be estimated. The residue data reviewed by the panel were mainly from monitoring studies conducted by the PDA using multiresidue methods to analyze fresh produce and market basket samples collected from various geographic areas (81,82). These and other rehable scientific studies have demonstrated that relatively few food samples contain detectable residues. Most residues are far below estabhshed tolerances which are set above the maximum residue found in treated raw agricultural... 

For detection residue amounts of tetracyclines in dairy products widely used methods FIPLC, immunoaffinity chromatography, kinetic spectrophotometry, which are expensive and complicated. 

Lyvers M, Hashing P Have Halpern et al. (2004) detected residual neuropsychological effects of MDMA not likely. Drug Alcohol Depend 75 149-152, 2004 Mack RB Marching to a different cactus peyote (mescaline) intoxication. N Engl J Med 47 137-138, 1986... 

The definitions of method detection and quantification limits should be reliable and applicable to a variety of extraction procedures and analytical methods. The issue is of particular importance to the US Environmental Protection Agency (EPA) and also pesticide regulatory and health agencies around the world in risk assessment. The critical question central to risk assessment is assessing the risk posed to a human being from the consumption of foods treated with pesticides, when the amount of the residue present in the food product is reported nondetect (ND) or no detectable residues . 

Today, when a pesticide with no detectable residues is registered for use, a Tolerance or maximum residue limit (MRL) is established at the lowest concentration level at which the method was validated. However, for risk assessment purposes it would be wrong to use this number in calculating the risk posed to humans by exposure to the pesticide from the consumption of the food product. This would be assuming that the amount of the pesticide present in all food products treated with the pesticide and for which no detectable residues were found is just less than the lowest level of method validation (LLMV). The assumption is wrong, but there is no better way of performing a risk assessment calculation unless the limit of detection (LOD) and limit of quantification (LOQ) of the method were clearly defined in a uniformly acceptable manner. 

This policy seems to be rational and would be of tremendous help to registrants in getting more uses registered for their products. This would be especially useful when new uses (worth millions of dollars to the registrant) were to be added to the label in cases where no detectable residues were found in the food product and the risk cup (cumulative exposure risk) was nearly full. The following example highlights this point ... 

If no detectable residues were present, the value used for risk assessment purposes would be 0.05 mg kg This would allow only four uses with no detectable residues and even fewer uses where residues were present. If an appropriate LOD and LOQ had been calculated and reported as follows ... 

Information from the summary table in each workbook was directly imported into a master compilation of analytical results. The compilation could then be manipulated as desired to present the data in various ways. For example, the compilation could be searched for the number of apple samples that contained no detectable residues of any analyte or for the number of tomato samples that required dilution and reanalysis. 

Oxime carbamates are generally applied either directly to the tilled soil or sprayed on crops. One of the advantages of oxime carbamates is their short persistence on plants. They are readily degraded into their metabolites shortly after application. However, some of these metabolites have insecticidal properties even more potent than those of the parent compound. For example, the oxidative product of aldicarb is aldicarb sulfoxide, which is observed to be 10-20 times more active as a cholinesterase inhibitor than aldicarb. Other oxime carbamates (e.g., methomyl) have degradates which show no insecticidal activity, have low to negligible ecotoxicity and mammalian toxicity relative to the parent, and are normally nondetectable in crops. Therefore, the residue definition may include the parent oxime carbamate (e.g., methomyl) or parent and metabolites (e.g., aldicarb and its sulfoxide and sulfone metabolites). The tolerance or maximum residue limit (MRL) of pesticides on any food commodity is based on the highest residue concentration detected on mature crops at harvest or the LOQ of the method submitted for enforcement purposes if no detectable residues are found. For example, the tolerances of methomyl in US food commodities range from 0.1 to 6 mg kg for food items and up to 40 mg kg for feed items. ... 

Cell link was dosed to Loop 1 water and after eight hours it was possible to detect residual HP in water going into the common filtrate tank. After two days residual HP was detected even in the water going into the pulper. 

Type and quanity of residuals No residuals remain remaining after treatment None No detectable residuals in Area 2 remain carbon from gaseous treatment requires regeneration No detectable residuals in Area 2 remain 30 000 cy of fixed soils remain in Area 1 Incinerated soil (18,000 cy) and fixed soil (30,000 cy) remain incinerated soil expected to nonhazardous carbon from gaseous treatment remains requiring regeneration... 

The acceptable operator exposure level (AOEL) for each route of exposure is assigned from the no effect level (NOEL) in a specific toxicity test multiplied by a safety factor. The value for samples containing no detectable residues is assumed to be one half the limit of detection. For cyromazine, the seasonal use pattern indicates that the exposure is most comparable to the 21-day dermal exposure interval, and a value of 2000 mg/kg bw/day was taken as the dermal AOEL. The inhalation AOEL was obtained from a 28-day inhalation study with rats. As cyromazine is not a carcinogen, the safety margin used for calculation of the of the results using the EEC method... 

Houk RJT, Wallace KJ, Hewage HS, Anslyn EV (2008) A colorimetric chemodosimeter for Pd(II) a method for detecting residual palladium in cross-coupling reactions. Tetrahedron 64 8271-8278... 

Production method No detectable Residues below Residues above... 

Tobacco homworms (Manduca sexta) from a field sprayed with 840 mg diazinon/ha contained no detectable residues of diazoxon. Only one sample, collected about 4 h after spraying, exceeded 1.0 mg diazinon/kg body weight. No diazinon residues in these insects were detectable after 18 days. 

Oral treatment of sheep and cattle (Bos spp.) with diflubenzuron is followed by absorption of the compound through the gastrointestinal tract, metabolism, and elimination of residues through the urine, feces, and, to a very limited extent, milk. Intact diflubenzuron is eliminated in the feces of orally dosed cattle and sheep (Ivie 1978). Major metabolites of diflubenzuron excreted by cattle and sheep result from hydroxylation on the difluorobenzoyl and chlorophenyl rings, and by cleavage between the carbonyl and amide groups to produce metabolites that are excreted free or as conjugates (Ivie 1978). Cattle dosed repeatedly with diflubenzuron had detectable residues only in liver... 

No detectable residues in milk and tissues, except liver (0.01 mg/kg FW) liver residues remained detectable after a 7-day withdrawal period No detectable residues in milk and tissues, except liver (0.08 mg/kg FW) liver residues remained detectable after a 7-day withdrawal period Liver residue of 0.54 mg/kg FW remained elevated after a 7-day withdrawal period residues in milk reached 0.013 mg/L within the first few days of feeding and declined to nondetectable (ND) levels after a 4-day withdrawal period No detectable residues in any tissue. Tb 1/2 of 4-5 days in manure manure gave >95% control of larvae of the face fly, Musca autumnalis No detectable residues in any tissue except omental fat (0.1 mg/kg FW). No houseflies (Musca domestica) or face flies developed in manure No detectable diflubenzuron residues in heart, muscle, or kidney 130 pg/kg FW in liver about 250 pg/kg FW in subcutaneous fat... 

Results from imported foods were somewhat similar, although violation rates were higher and the rates of residue detection were lower. Of the 4374 imported samples analyzed for pesticide residues, 72.0% had no detectable residues, 23.2% had detectable residues within legal limits, and 4.8% had violative residues. Violations were observed in the other category (8.1%), vegetables (6.4%), fruits (2.8%), and fish, shellfish, other aquatic products (0.3%). 

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