Plant residue analytical methods

Nature of residue in plants, Hvestock Residue analytical method (plants, animals)... 

Annex VI to Directive 91/414/EEC concerning the placing of plant protection products on the market. The section concerning residue analytical methods was not fully finalized when the Directive was first adopted. There were no provisions for methods to determine residues from a.i. and relevant metabolites in soil, water, and air. The criteria for foodstuffs partly proved to be not helpful for the practice of assessment (e.g., with regard to reproducibility, ISO 5725 requires validation in at least eight independent laboratories). 

OPPTS 860.1000 Background OPPTS 860.1100 Chemical Identity OPPTS 860.1200 Directions for Use OPPTS 860.1300 Nature of Residue - Plants, Livestock OPPTS 860.1340 Residue Analytical Method OPPTS 860.1360 Multiresidue Method OPPTS 860.1380 Storage Stability Data OPPTS 860.1400 Water, Fish, Irrigated Crops OPPTS 860.1460 Food Handling OPPTS 860.1480 Meat/Milk/Poultry/Eggs OPPTS 860.1500 Crop Field Trials OPPTS 860.1520 Processed Food/Feed OPPTS 860.1550 Proposed Tolerances... 

A The Multi-residue analytical method is provided for plant, soil and water samples. 

All of the compounds (pyraflufen-ethyl and its metabolites) are converted to E-2 and quantified as the total toxic residue of pyraflufen-ethyl. The conversion to E-2 is carried out by oxidative decomposition with concentrated sulfuric acid. The reaction mixture is extracted with a solvent and subjected to simple cleanup, followed by GC/NPD analysis. This method is rapid and simple compared with the Multi-residue analytical method , and has wide applicability to different varieties of the samples, such as plant materials, soils and water, with only minor adjustment of the analytical method. 

Four different types of residue analytical methods of flutolanil and its metabolites are developed for plant (potato and rice), soil and water ... 

Total toxic residue analytical method (for rice plant)... 

Buprofezin and its metabolites, p-OH-buprofezin and BF12, are hydrophobic under neutral conditions. Having the organic base part in their chemical structure, these compounds form water-soluble salts under strongly acidic conditions. The change in solubilities of these compounds influences the cleanup procedure. Four different residue analytical methods have been developed to measure buprofezin and its metabolites in plants (rice, citrus and tomato cucumber, pepper, tomato, squash and eggplant), soil and water ... 

A Multi-residue analytical method (for plants) is used for rice, citrus and tomato. Buprofezin and p-OH-buprofezin (as the acetylated derivative, p-AcO-buprofezin) are analyzed simultaneously using gas chromatography/nitrogen-phosphorus detection (GC/NPD). 

Multi-residue analytical method (for plant and soil) is provided for plants (apple, grape etc.) and soil samples. After GPC cleanup, fenpyroximate and M-1 are analyzed simultaneously using gas chromatography (GC)/NPD. 

Multi-residue analytical method (for plants and soil) 3.1 Apparatus... 

ImperialChemical Industries Ltd., Plant Protection Division Residue Analytical Method No. 62. August 1981. 

An independent laboratory validation (ILV) must be submitted for a primary method with monitoring purposes and used to determine residues in plants, plant products, foodstuff, and feedingstuff. The LOQ of the primary method shall be confirmed by the ELV, but at least the MRL. If validation data for the residue analytic method of an analyte in at least one of the commodities of the respective matrix group have been provided by an international official standardization body and if these data have been generated in more than one laboratory with the required LOQ, acceptable recovery, and acceptable relative standard deviation (RSD) data, no additional ELV is required [45]. 

Another quaHty control problem of multipurpose plants is the clean out for a product change. A test for residual cleaning solvents in the ppm level is a necessity. The best vaHdation of the cleaning process is to develop an analytical method that is able to find the previous product in the new product at a level of not more than 1 ppm. Tests should be mn on at least the first three batches. 

As a special service, the German authority has published reviews on residue analysis concerning new a.i. contained in plant protection since 1996, including selected physical-chemical data. Recoveries obtained in fortification experiments and LOQs for analytical methods for determination in crops, food of plant and animal origin. 

Residues of alachlor and acetochlor are determined by similar methods involving extraction, hydrolysis to the common aniline moieties, and separation and quantitation by reversed-phase FIPLC with electrochemical detection. The analytical method for acetochlor is included as a representative method for residue determination of alachlor and acetochlor in plant and animal commodities. Propachlor and butachlor residues, both parent and metabolite, are determined by similar analytical methods involving extraction, hydrolysis to common aniline moieties, and separation and quantitation by capillary GC. The analytical method for propachlor is included as a representative method. The details of the analytical methods for acetochlor and propachlor are presented in Sections 4 and 5, respectively. Confirmation of the residue in a crop or... 

The minimum detectable level is estimated with the dinifroaniline signal-to-noise ratios (S/N). With fortification levels between 0.2 and 0.5mgkg the recovery of trifluralin from plant matrices is 70-99% with the LOD/LOQ being 0.005 mg kg according to the analytical method of the Ministry of the Environment, Japan. In multiresidue analysis by GC/NPD, the percent recoveries of pendimethalin from each crop with a fortification level of 0.25 mg kg were brown rice 70, potato 70, cabbage 80, letmce 89, carrot 84, cucumber 64, shiitake 74, apple 76, strawberry 99, and banana 99%. The LOD for each sample was 0.01 mg kg for pendimethalin. In residue analysis by GC/ECD, recoveries of the majority of dinifroaniline herbicides from fortified samples of carrot, melon, and tomato at fortification levels of 0.04—0.10 mg kg ranged from 79 to 92%. The LODs were benfluralin 0.001, pendimethalin 0.002 and trifluralin 0.001 mg kg for the GC/ECD method. ... 

The aforementioned series of reactions provides a basis for a colorimetric analytical method for Compound 118 in which the commonly used agricultural chemicals do not interfere. The procedure described herein permits the estimation of as little as 10 micrograms of Compound 118, and has been successfully applied to the analysis of this insect toxicant in insecticidal dusts, in film residues on glass and paper, in human and animal urine, and in mixture with other insecticides. Application of this procedure to the determination of Compound 118 in milk and in spray and dust residues on plants appears promising. 

Nash RG, Wells MJ, Smith AE, et al. 1986. Pesticide residues in environmental samples. In Zweig G, ShermaJ, eds. Analytical methods for pesticides and plant growth regulators. Vol 15. New York, NY Academic Press, 247-286. 

The determination of diazinon in foods is important because this chemical is used as a pesticide on plant crops and, at least in some cases, in pesticide dips for the control of parasitic infestations in animals (Brown et al. 1987 Miyahara et al. 1992). Because animals are exposed to this compound, both via pesticide dips and by ingestion of crops to which diazinon has been applied, some methods have been reported for animal products. The majority of methods, however, deal with the determination of residues in plant products. Most of the analytical methods found that describe the extraction from, and determination of, diazinon residues in various crops (plant materials) were developed as part of multiresidue methods. They are based on homogenization of the sample with an organic solvent (polar or non-polar) the isolation of the residues from this initial extract and, usually, some additional cleanup prior to the analysis of the extract by GC. The most common non-MS modes of detection exploit the... 

---