Determination of bromoxynil octanoate in soil and corn by GC with electron capture and mass spectrometry detection under field conditions.

In this paper, a simple, and rapid analysis of bromoxynil octanoate is reported for soil, corn leaves, and corn seeds by utilizing one-step liquid-liquid extraction and partitioning, followed by GC with electron capture (ECD) and mass spectrometry (MS) detection. The method was validated by recovery experiments and assessment of matrix effects. Recoveries for GC-ECD and GC/MS were 82.3-110.7% with a relative standard deviation of <14% using matrix-matched calibration solutions for quantification. The limit of quantitation (LOQ) values were 0.005 and 0.2 mg/kg for the ECD and MS detector, respectively, depending on the sensitivity of the target compound. The concentration levels for bromoxynil octanoate residue found in soil, corn leaves, and corn seeds from field experiments were clearly below the LOQ of the ECD detector. The half-life times of bromoxynil octanoate were 2.2-4.2 days in soil and corn leaves. These results indicated that the developed method was appropriate for analysis of bromoxynil octanoate in soil and corn samples.