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Abstract: A simple and fast 1H NMR method, without any pretreatment, was developed for quality control of gasoline. It is based on the average group molecular weight approach and relative-content concept involving aromatics, olefinics and paraffinics, including also ethanol and benzene contents. The ethanol content was evaluated for Brazilian samples, but the method can be easily adapted to any oxygenated compound (ex. MTBE), and to gasoline from other countries. Twenty two laboratory prepared gasoline samples (gasoline from Brazilian refineries plus hydrocarbon solvents) and thirty four real (i.e., Brazilian gas stations) gasoline samples were tested. The routine quality control carried out through the usual physicochemical analyses reached a level of confidence of 75% and 73% in detecting non conformity in laboratory and real gasoline samples, respectively. The NMR method was very superior reaching 100% and 97% of confidence, respectively. It was better suited for laboratories with high sample throughput since measurement time is short and only one NMR experiment is needed per sample. [Copyright &y& Elsevier]

• Influence of no-till on nutrient losses by runoff and erosion. • Monitoring of stormwater events at the hillslope and catchment scale. • Nutrient concentration in runoff is high regardless of management. • The losses depends essentially on runoff control practices such as terraces. No-till farming is widely used in grain production in Brazil. However, the lack of runoff control and the low phytomass input are major causes of soil degradation. In addition, surface runoff transports chemical elements, including carbon and nutrients, in dissolved and particulate forms impacting water quality. Given this scenario, this study sought to evaluate the influence of phytomass amount, chiseling, and terracing on nutrient loss (NH 4 +, NO 3 − + NO 2 −, total N, P, K, Ca, Mg, Cu, and Zn) associated with surface runoff, suspended sediments, and to quantify their presence in sediment deposits at the end of the monitoring unit. This study was based on hydrological monitoring in four macroplots and two paired zero-order catchments during rainfall events. The macroplots reproduce use or absence of chiseling with lower or higher phytomass input, and the catchments, presence or absence of terraces. Nutrient concentrations were determined in surface runoff and sediment. In surface runoff, the highest median values of NH 4 +, NO 3 − + NO 2 −, total N, P, K, Ca, Mg, Cu and Zn concentrations in the catchments were 0.9,1.0, 1.5, 0.1, 3.1, 3.9, 1.1, 0.0, and 0.01 mg/L, and in the macroplots 1.0, 1.2, 2.1, 0.2, 3.4, 5.3, 1.7, 0.0, and 0.02 mg/L. In the suspended sediments, the highest median values of P, K, Ca, and Mg concentrations in suspended sediment in the catchments were 0.6, 6.7, 3.4, and 0.8 g kg−1 and in the macroplots 0.6, 6.1, 1.9 and 0.7 g kg−1. Our findings revealed a wide variation in nutrient concentrations in runoff and sediments regardless of the management practices. Nevertheless, the dissolved fraction of surface runoff controls the loss of nutrients during high-magnitude rainfall events. The effects of the increased phytomass and the presence of terraces, affect nutrient losses due to runoff control. [ABSTRACT FROM AUTHOR]