A fast and simple SPE-LC-MS/MS procedure for extraction and quantitative analysis of 1,2,4-triazole, N,N-dimethylsulfamide, and other small polar organic compounds in groundwater

Small polar organic pollutants have been discovered to be great threats to the groundwater‚ as they often are highly mobile and persistent in the environment. 1,2,4-Triazole and N,N-dimethylsulfamide, two well-known examples of small polar compounds, are frequent pollutants of upper groundwater. Both are degradation products of several fungicides commonly or previously used in agriculture‚ but also in wood-preserving paints. A common trait in the analysis of these small polar compounds is the lack of sufficient pre-concentration methods to lower the limit of detection and enable quantitative analysis at nano-scale concentrations. To date, they are analyzed only by direct injection in HPLC-MS/MS, with detection limits just below the European threshold value for pesticides in groundwater of 0.1 μg/L. Based on a comprehensive method development, a solid phase extraction method was developed. As known LC methods for analysis of 1,2,4-triazole are based on Thermo Fisher’s Hypercarb column, emphasis was placed on testing various carbon-based materials. The final, thoroughly validated extraction protocol is based on Supelco’s ENVI-Carb Plus cartridges. With extraction recoveries close to 100% for 1,2,4-triazole and N,N-dimethylsulfamide and quantification limits of around 0.003 μg/L, the method enables extraction and quantification of polar pollutants at nano-scale concentration from groundwater samples. In addition, the method is very promising to be used for other small polar pollutants.