Pesticide Analytical Manual Vol. I SECTION 102 102: PREPARATION OF ANALYTICAL SAMPLES 102 A: INTRODUCTION This section contains directions for preparation of test samples of food from labo- ratory samples collected for pesticide residue analysis. The following topics are considered, but not all are pertinent to every sample situation: (1)instructions for portion of commodity to be analyzed for pesticide residues,(2)directions for compositing and comminuting food items, ( 3)procedures for samples that are to undergo special analyses, and(4)requirements for retention of reserve portions of test samples 102 B: PORT/ON OF FOOD COMMODITY TO BE ANALYZED As a general approach, the"portion of commodity"composited to create the test sample consists of the entire food commodity(e.g, whole cantaloupe). For many raw and processed foods, however, only specific portions of the food are included in the composite for the test sample to ensure uniformity and consistency in tolerance enforcement and related monitoring, it is necessary to adhere to the following instructions on the portion of comm odity to be analyzed Raw Agricultural Commodities EPA regulations [1] specify that a raw agricultural commodity examined for com- pliance with a pesticide tolerance consist of the " whole raw agricultural commod- ity. The regulations contain some specific instructions on what constitutes the hole raw agricultural commodity; e.g,"caps(hulls) shall be removed and dis- carded from strawberries before examination for pesticide residues. " Such instruc- tions are provided for only nine individual food commodities(e.g, bananas) and crop group commodities (e.g, root vegetables) Recognizing the limitation of these regulations, FDA developed directions for additional commodities, taking into account practical considerations of sample preparation (e.g, removal of stones from peaches to facilitate preparation of a homogenate). Table 102-a is a compilation of EPA regulations and FDa direc- tions(An EPA rulemaking is expected to be initiated that would amend the above existing regulation to incorporate FDA's more complete instructions on the por tion of commodity to which a tolerance applies and that is to be analyzed.) In some instances, a pesticide tolerance regulation specifies an exception to direc- tions in Table 102-a. For example, the tolerance for mevinphos residues on mel- ons states that compliance with the tolerance is to be "determined on the edible portion with rind removed, [2] even though the tolerances for most other pes- ticides on melons apply to the whole commodity including the rind. Follow these directions to prepare test samples of raw agricultural commodities Use the entire raw agricultural commodity, as specified in Table 102-a. When a pesticide residue is found in a commodity for which the tolerance applies to a portion different from that specified in Table 102-a, prepare a new test sample in accordance with the pesticide's tolerance regulation. mittal No.94101/94 m FDA 2905a(6/92 102-1SECTION 102 102–1 Transmittal No. 94-1 (1/94) Form FDA 2905a (6/92) Pesticide Analytical Manual Vol. I 102: PREPARATION OF ANALYTICAL SAMPLES 102 A: INTRODUCTION This section contains directions for preparation of test samples of food from labo￾ratory samples collected for pesticide residue analysis. The following topics are considered, but not all are pertinent to every sample situation: (1) instructions for portion of commodity to be analyzed for pesticide residues, (2) directions for compositing and comminuting food items, (3) procedures for samples that are to undergo special analyses, and (4) requirements for retention of reserve portions of test samples. 102 B: PORTION OF FOOD COMMODITY TO BE ANALYZED As a general approach, the “portion of commodity” composited to create the test sample consists of the entire food commodity (e.g., whole cantaloupe). For many raw and processed foods, however, only specific portions of the food are included in the composite for the test sample. To ensure uniformity and consistency in tolerance enforcement and related monitoring, it is necessary to adhere to the following instructions on the portion of commodity to be analyzed. Raw Agricultural Commodities EPA regulations [1] specify that a raw agricultural commodity examined for com￾pliance with a pesticide tolerance consist of the “whole raw agricultural commod￾ity.” The regulations contain some specific instructions on what constitutes the whole raw agricultural commodity; e.g., “caps (hulls) shall be removed and dis￾carded from strawberries before examination for pesticide residues.” Such instruc￾tions are provided for only nine individual food commodities (e.g., bananas) and crop group commodities (e.g., root vegetables). Recognizing the limitation of these regulations, FDA developed directions for additional commodities, taking into account practical considerations of sample preparation (e.g., removal of stones from peaches to facilitate preparation of a homogenate). Table 102-a is a compilation of EPA regulations and FDA direc￾tions. (An EPA rulemaking is expected to be initiated that would amend the above existing regulation to incorporate FDA’s more complete instructions on the por￾tion of commodity to which a tolerance applies and that is to be analyzed.) In some instances, a pesticide tolerance regulation specifies an exception to direc￾tions in Table 102-a. For example, the tolerance for mevinphos residues on mel￾ons states that compliance with the tolerance is to be “determined on the edible portion with rind removed,” [2] even though the tolerances for most other pes￾ticides on melons apply to the whole commodity including the rind. Follow these directions to prepare test samples of raw agricultural commodities: • Use the entire raw agricultural commodity, as specified in Table 102-a. • When a pesticide residue is found in a commodity for which the tolerance applies to a portion different from that specified in Table 102-a, prepare a new test sample in accordance with the pesticide’s tolerance regulation