Comparative Study of Glyphosate and AMPA Determination in Environmental Samples by Two Green Methods

Glyphosate, N-phosphonomethyl-glycine (GLY), is a systemic post-emergence herbicide that controls weeds with great efficiency whose low cost is reflected in its wide application. In the environment, the presence of aminomethylphosphonic acid (AMPA), its main degradation product, is indicative of the application of GLY to the land. The aim of this study was to develop two analytical methods for the determination of GLY by HPLC-UV and GLY and AMPA by GC-MS, in water, soil and sediment samples. The proposed HPLC-UV method proved to be an efficient way of determining GLY in environmental samples of water, soil and sediment, eliminating the step of extraction and clean-up. On the other hand, the GC-MS method can be used to determine both GLY and AMPA simultaneously. The limits of detection (LOD) and quantitation (LOQ) for GLY by the HPLC method were 9.93 and 30.1 μg·L^﹣1 for water samples, and 0.040 and 0.120 mg·kg^﹣1 for soil and sediment samples, respectively. By the GC-MS method, the LOD and LOQ for GLY were 0.67 and 2.02 μg·L^﹣1 for water samples, and 0.0027 and 0.0081 mg·kg^﹣1 for soil and sediment samples, respectively. For AMPA, these limits were 0.15 and 0.45 μg·L^﹣1 for water samples and 0.0006 and 0.0018 mg·kg^﹣1 for soil and sediment samples, respectively. The recoveries ranged from 70% to 120% for water, soil and sediment samples.