Separate Analysis of Loquat Fruit Pulp, Peel, and Pits to Calculate Pesticide Residue Levels in the Whole Commodity.

To evaluate the effects of handling "not detectable" residues (ND: <0.01 mg/kg) in the pulp and detectable residues in the pits on the calculation of pesticide residue in the whole fruit, residue levels in the pulp, peel, and pits of loquat fruits were separately analyzed. Following conventional Japanese agricultural practices, 16 pesticides were sprayed at the maximum application rates in three test fields.

Influences of sample homogenization time and standing time before extraction on the determination of incurred pesticide residue levels in grapes.

To estimate the influence of sample processing with a blender, we conducted a homogeneity test using a bulk sample of pre-harvest grapes. Relative standard deviations (RSDs) were calculated from the concentrations of pesticides in the portions from the top, middle, and bottom of the homogenate with fine and rough particles. The results from adequate sample processing showed that the RSDs of the residue levels of all five pesticides in the fine-particle homogenate were lower than 10%.

Effect of sample preparation on the estimation of residue levels of sprayed pesticides in separate analyses of turnip roots and leaves: inclusion or exclusion of the root-shoot junction.

The effect of inclusion or exclusion of the root-shoot junction on the estimation of pesticide residue levels in turnip roots and leaves was investigated. Turnips grown at two experimental sites were sprayed with six pesticides. At residue analysis, the turnips were divided in three segments: roots (R), leaves (L), and root-shoot junctions (J).

Influence of various parts of sweet corn ears on pesticide residue levels.

Pesticide residue levels in various parts of sweet corn ears were analyzed. For this purpose, five pesticides were sprayed on corn in two different fields, and the harvested samples were separated into four portions, namely kernels, cobs, silks, and husks. Each of these portions was then separately analyzed.

Effect of sampling size on the determination of accurate pesticide residue levels in Japanese agricultural commodities.

The uncertainty in pesticide residue levels (UPRL) associated with sampling size was estimated using individual acetamiprid and cypermethrin residue data from preharvested apple, broccoli, cabbage, grape, and sweet pepper samples. The relative standard deviation from the mean of each sampling size (n = 2(x), where x = 1-6) of randomly selected samples was defined as the UPRL for each sampling size. The estimated UPRLs, which were calculated on the basis of the regulatory sampling size recommended by the OECD Guidelines on Crop Field Trials (weights from 1 to 5 kg, and commodity unit numbers from 12 to 24), ranged from 2.

Comparison of the variability in the levels of pesticide residue observed in Japanese cabbage and grape units.

To estimate variations in pesticide residue levels in crops, the variability factors (VFs, the 97.5th percentile of the residue levels in the sample divided by the average residue levels in the lot) in residue levels of acetamiprid and cypermethrin applied to cabbage and grapes were investigated, respectively. The VFs in the residue levels of both pesticides in cabbage (2.