Analysis of a new herbicide (pyribenzoxim) residues in soil using direct-extract-injection HLPC with column switching

A simple and efficient analysis method of the herbicide residues in soil has been developed and applied to residual analysis of a new herbicide, pyribenzoxim. Extraction and separation were performed in sequential mode by on-line column switching. On-line analysis shows better specificity than off-line analysis does. The analyte was well separated without interference and baseline distortion. Recovery yields for standard spiking were 97.9 ± 1 (S.D.) and 92.1 ± 4 (S.D.) % at the concentration of 0.04 and 0.1 ppm in soil, respectively (n=3). The correlation coefficient was greater than 0.999 over the range between 0.1 and 10/mL. The on-line solid phase extraction (SPE) analysis is described, as compared to off-line SPE analysis.