I. PURPOSE - The purpose of this document is to detail the standard operating procedure for the screening of cholinesterase
inhibiting carbamate insecticides in fruits, vegetables, and feeds using the SDI Food Prep Kit and InQuest OP/Carbamate Screening Kit.
NB - This is a screening technique designed to determine presence or absence of cholinesterase inhibiting pesticides, therefore,
positive results may indicate presence of a broad range of cholinesterase inhibiting compounds necessitating confirmation of
compound identity and concentration by P-703 - HPLC with Post column derivitization.
II. SCOPE - This standard operating procedure should be employed on all samples of fruits, vegetables, and feeds analyzed by the pesticide enforcement laboratories for carbamate insecticides.
III. RESPONSIBILITY - It is the responsibility of the Laboratory Associate to assure that all personnel analyzing fruits, vegetables, and feeds for carbamate insecticides follow this standard operating procedure without exception.
IV. REFERENCES -
Bull. Environ. Contam. Toxicol. (1990)45:120-124
A New Sample Preparation System for Immunoassay Detection of Pesticides on Fruit. Poster presented at the California Pesticide
Residue Workshop, February, 1994. Jourdan, Scutellaro, Hayes, and Herzog. Ohmicron.
V. RELATED DOCUMENTS -
Intra-Laboratory Method Validation for the Screening of Fruits, Vegetable and Feeds for Carbamate Residues using the SDI Food
Prep and InQuest OP/Carbamate Screening Kit., Ga. Dept. of Agri. - Chemical Laboratories Div. Farrow and Nuga. 1996.
VI. DEFINITIONS -
Extract Cleanup Reagent - A Food Prep Kit reagent (pre-packaged in tubes) containing a powdered adsorptive polymer
mixture which adsorbs interfering phenolic compounds such as flavenoids.
Salt Reagent - A Food Prep Kit reagent (in a bulk bottle) used to effect separation of the aqueous and organic phases (water:
acetone) so that an aliquot of the organic phase can be obtained.
Measuring Scoop - The scoop used to add the Salt Reagent to the Extract Cleanup Reagent tube.
Buffer/Chromogen Reagent - A OP/Carbamate Kit reagent consisting of buffer salts and color indicator reagent (prepackaged
NB - After this is mixed with the sample extract from the Food Prep Kit, this reagent will compete with any carbamate present
for reaction with the Cholinesterase Reagent.
Cholinesterase Reagent - An OP/Carbamate reagent containing lyophilized acetyl cholinesterase and preservatives (prepackaged
in blue top tubes).
NB - The Cholinesterase Reagent will complex with the Chromogen to form a dark blue to indigo color in the absence of a
cholinesterase inhibitor which might other wise out- compete the Chromogen for the Cholinesterase resulting in reduced
intensity of color.