2.1. Chemicals All chemicals and solvents used were HPLC spectral grade, and obtained from Sigma (St. Louis, USA) from Merck – Shcuchrdt (Munich, Germany).
2.1. ChemicalsAll chemicals and solvents used were HPLC spectral grade,and obtained from Sigma (St. Louis, USA) from Merck –Shcuchrdt (Munich, Germany).