Analysis of methoxyfenozide residues in fruits, vegetables, and mint by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Methoxyfenozide [3-methoxy-2-methylbenzoic acid 2-(3,5-dimethylbenzoyl)-2-(1,1-dimethylethyl) hydrazide; RH-2485], in the formulation of INTREPID, was applied to various crops. Analysis of methoxyfenozide was accomplished by utilizing liquid-liquid extraction and partitioning, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validations for fruits, vegetables, and mint are reported. Methoxyfenozide mean recoveries ranged from 72 to 129% over three levels of fortification. The overall average of mean recoveries is 97 +/- 10%. The limit of quantitation for fruits, artichoke, cucumber, squash, and refined sugar was 0.010 ppm, with a detection limit of 0.005 ppm. For all other crops, the limit of quantitation was 0.050 ppm, with a detection limit of 0.025 ppm. No residues were found greater than the limit of quantitation in control samples. Residues above the limit of quantitation were found in all matrices except refined sugar. Foliage (bean, beet, pea, and radish) had greater residue levels of methoxyfenozide residue than their corresponding roots or pods. Other crop matrices contained <1.0 ppm of methoxyfenozide except artichoke, which had a mean of 1.10 ppm.

Analysis of fenhexamid in caneberry, blueberry, and pomegranate by liquid chromatography-tandem mass spectrometry.

An analytical method for the determination of fenhexamid [N-(2,3-dichloro-4-hydroxyphenyl)-1-methylcyclohexanecarboxamide] in caneberry, blueberry, and pomegranate was developed utilizing acetone extraction, column cleanup, liquid-liquid partitioning, and liquid chromatography-tandem mass spectroscopy (LC-MS/MS) for detection. Method validation recoveries ranged from 91 to 96% for caneberry, from 80 to 91% for blueberry, and from 74 to 95% for pomegranate. Control samples collected from IR-4 trials for all matrixes had residue levels of <0.020 ppm. Fenhexamid-treated field samples had residue levels that ranged from 0.46 to 16.11 ppm (caneberry), from 0.87 to 2.91 ppm (blueberry), and from 1.59 to 1.85 ppm (pomegranate). The method was validated to a limit of quantitation of 0.020 ppm, and the limit of detection was 0.009 ppm.