EPA Method 508.1 includes many of the same components as Method 505, but it also contains several other compounds, including chlorinated pesticides, herbicides, and organohalides. In order to increase sample throughput, an optimized method is shown here using a dual column configuration with the Rtx-CLPesticides/Rtx-CLPesticides2 column pair. These columns, used under the conditions shown, offer a unique selectivity that allows the target analytes to be resolved in approximately half the analysis time of the original method. Further, both columns easily passed the comprehensive system performance criteria adapted from 508.1 (see table below). The unique selectivity of the Rtx-CLPesticides/Rtx-CLPesticides2 column pair offers an ideal balance of speed and resolution for chlorinated pesticide, herbicide, and organohalide analysis.
Rtx-CLPesticides and Rtx-CLPesticides2 columns easily pass Method 508.1 performance criteria.
80 °C (hold 0.5 min) to 155 °C at 19 °C/min (hold 1 min) to 210 °C at 4 °C/min to 310 °C at 25 °C/min (hold 0.5 min)
Carrier Gas
He, constant flow
Linear Velocity:
26 cm/sec
Detector
Micro-ECD @ 325 °C
Notes
This chromatogram was obtained using an Agilent micro-ECD. To obtain comparable results, you will need to employ a micro-ECD in addition to confirmational dual columns connected to a 5-meter guard column using a “Y” Press-Tight connector.
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