The same amount of product was washed under different conditions; 40 °C and 70 °C under constant stirring and ultrasonic extraction with different washing times (2, 4, 6, and 8 h) and two (14:1 and 28:1) water to α-CD-NS ratios.
To perform the experiments, 0.14 g of product were initially rinsed with 10 mL of Milli Q water to dissolve the unreacted CDI. The solution was then centrifuged at 4350 rpm using a VWR Mega Star 600R centrifuge (Radnor, PA, USA), and the supernatant was taken for further analysis. Then, the product was washed, changing only one of the above conditions at a time. At every time point, the solution was centrifuged using the same conditions as above, and the supernatant and pellet were kept for HPLC-DAD and nitrogen content analysis, respectively. The pellet was dried at 50 °C until a constant weight was obtained, and its nitrogen content was determined via elemental analysis on a Perkin Elmer 2400 Series II CHNS/O Organic Elemental Analyzer (Waltham, MA, USA) using optimum burning conditions and pure oxygen atmosphere.
To perform the experiments, 0.14 g of product were initially rinsed with 10 mL of Milli Q water to dissolve the unreacted CDI. The solution was then centrifuged at 4350 rpm using a VWR Mega Star 600R centrifuge (Radnor, PA, USA), and the supernatant was taken for further analysis. Then, the product was washed, changing only one of the above conditions at a time. At every time point, the solution was centrifuged using the same conditions as above, and the supernatant and pellet were kept for HPLC-DAD and nitrogen content analysis, respectively. The pellet was dried at 50 °C until a constant weight was obtained, and its nitrogen content was determined via elemental analysis on a Perkin Elmer 2400 Series II CHNS/O Organic Elemental Analyzer (Waltham, MA, USA) using optimum burning conditions and pure oxygen atmosphere.