Determination of spinosad and its metabolites in food and environmental matrices. 1. High-performance liquid chromatography with ultraviolet detection

Spinosad is an insect control agent that is derived from a naturally occurr ing soil bacterium and is effective on several classes of insects, especial ly Lepidoptera larvae. Spinosad is registered in many countries for use on a variety of crops, including cotton, corn, soybeans, fruits, and vegetable s. Residue methods utilizing high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection have been described for determining spinosa d and its metabolites in environmental and food matrices. These residue met hods typically involve an extraction with organic solvents, followed by pur ification using Liquid-liquid partitioning and/or solid phase extraction pr ior to measurement by HPLC-UV. The residue methods determine the active ing redients (spinosyns A and D) and up to three minor metabolites (spinosyn B, spinosyn K, and N-demethylspinosyn D). The methods have validated limits o f quantitation ranging from 0.010 to 0.040 mug/g. This paper briefly review s the residue methodology for spinosad and metabolites in food and environm ental matrices and provides a summary of method validation results for 61. different sample types, including newly published results for 37 additional crop matrices and processed commodities.