Improved Resolution of Triazine Herbicides in Drinking Water and Wastewater

Often used for weed control, triazine herbicides have been found to have detrimental environmental and health effects. Much debate has focused on the level at which these compounds negatively impact health. To monitor and control human exposure to these herbicides, regulatory bodies have established allowable limits of triazines in drinking and wastewater.

In this study, two methods for triazine herbicide analysis are presented. They follow the Environmental Protection Agency's Method 536 for drinking water and Method 619 for wastewater, using LC–MSMS and GC–MS respectively.

Table 1: LC–MS-MS operating conditions.

Experimental Conditions

For EPA Method 536, an Applied Biosystems API 3000 LC/MS/MS was used. Operating parameters are displayed in Table 1. For EPA Method 619, an Agilent 6890/5975 was used. Operating parameters are displayed in Table 2.

Table 2: GC–MS operating conditions.

Results

LC–MS-MS provides the sensitivity needed to accurately quantitate and verify the identity of triazine herbicides in EPA Method 536. The conditions presented provide separation of the herbicides in less than 6 min, as shown in Figure 1. The narrow peaks observed result from the ultra-high efficiency of the Kinetex® 2.6 µm XB-C18 column. The short run time improves laboratory productivity and minimizes sample backlogs.

Figure 1: Resultant LC–MS-MS chromatogram of EPA Method 536 using Kinetex 2.6 µm XB-C18.

EPA Method 619 uses gas chromatographic means to detect a longer list of triazine herbicides by GC–MS, as shown in Figure 2. The Zebron™ ZB-50 column provides separation of all compounds, delivering confidence in qualitative and quantitative results.

Figure 2: Resultant chromatogram of EPA Method 619 using Zebron ZB-50.

Conclusions

Two successful methods have been presented to monitor triazine herbicides. The narrow peaks achieved with the Kinetex 2.6 µm XB-C18 core-shell technology column increased throughput without sacrificing resolution for LC-based EPA Method 536. The Zebron ZB-50 column provides separation of all 11 triazine herbicides for GC-based EPA Method 619.

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