A novel method was developed for the sensitive, cheap and fast quantitation of glyphosate, glufosinate and aminomethylphosphonic acid (AMPA) in irrigation water by in situ derivatization and dispersive liquid–liquid microextraction (DLLME) combined with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Water samples were filtered with a 0.22 μm nylon filter, pH adjusted to 9 with ammonium bicarbonate and derivatized with fluorenylmethyloxycarbonyl chloride (FMOC-Cl). Afterwards, DLLME was applied to concentrate the compounds of interest, which were then analyzed by UPLC-MS/MS. The best results were obtained when acetone and dichloromethane were used as dispersive and extraction solvents, respectively. Two-level full factorial designs and a central composite design were applied to select the most appropriate derivatization and DLLME conditions. The method performance was evaluated according to the SANTE/11945/2015 guidelines and was linear in the 1.0 to 200 μg L⁻¹ range for glyphosate, glufosinate and AMPA, with r² ≥ 0.997 and individual residuals <13%. Repeatability (RSD_r) and within-laboratory reproducibility (RSD_wr) ranged from 2.7 to 9.1% and from 3.4 to 14.3%, respectively, and the trueness between 94.9 and 118.1%. The limits of detection were 0.35, 0.05 and 0.10 μg L⁻¹ for glyphosate, glufosinate and AMPA, respectively and the limit of quantitation was 1.0 μg L⁻¹ for all three compounds. The developed method was successfully applied to the analysis of irrigation water (surface and groundwater). No sign of the three compounds was detected in the groundwater samples but glyphosate was quantified in surface waters.

Agriculture and food science literature on waste-to-value applications that allow upcycling of by-product ingredients is increasing. However, this stream of research rarely takes an international trade and sustainability systems perspective. This focused review defines the term of waste-to-value and the sustainable development goals connected to it, and points to the tensions and questions arising when international trade is involved. Further, it exemplifies the challenges and opportunities of waste-to-value in tropical fruit trade through five cases of tropical fruit from South America: Green coconut, açaí, maracujá, cambuci, and jabuticaba. We present a model of the international supply chain that indicates where the opportunities of waste-to-value applications in international tropical fruit trade are situated, and discuss which future research questions need to be addressed to tackle the challenges of waste-to-value in global tropical fruit chains. Establishing the waste-to-value approach in the export of yet-underused tropical fruits can amongst others improve local employment, preserve natural resources, allow favorable use of side-streams in local energy production, environmentally friendly packaging material for transport, and add health functionalities to the end-consumer products, but challenges have to be solved in order to ensure these environmental and social benefits materialize.